6.4.1-rc1 review
Greg Kroah-Hartman
maintainercover 6.4.1-rc1 review
This is the start of the stable review cycle for the 6.4.1 release. There are 28 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.
Responses should be made by Sat, 01 Jul 2023 18:41:39 +0000. Anything received after that time might be too late.
The whole patch series can be found in one patch at:
https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.4.1-rc1.gz
or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.4.y
and the diffstat can be found below.
thanks,
greg k-h
-------------
Pseudo-Shortlog of commits:
Greg Kroah-Hartman <[email protected]>
Linux 6.4.1-rc1
Ricardo Cañuelo <[email protected]>
Revert "thermal/drivers/mediatek: Use devm_of_iomap to avoid resource leak in mtk_thermal_probe"
Mike Hommey <[email protected]>
HID: logitech-hidpp: add HIDPP_QUIRK_DELAYED_INIT for the T651.
Ludvig Michaelsson <[email protected]>
HID: hidraw: fix data race on device refcount
Zhang Shurong <[email protected]>
fbdev: fix potential OOB read in fast_imageblit()
Hugh Dickins <[email protected]>
mm/khugepaged: fix regression in collapse_file()
Linus Torvalds <[email protected]>
gup: add warning if some caller would seem to want stack expansion
Jason Gerecke <[email protected]>
HID: wacom: Use ktime_t rather than int when dealing with timestamps
Linus Torvalds <[email protected]>
mm: always expand the stack with the mmap write lock held
Linus Torvalds <[email protected]>
execve: expand new process stack manually ahead of time
Liam R. Howlett <[email protected]>
mm: make find_extend_vma() fail if write lock not held
Linus Torvalds <[email protected]>
powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
Linus Torvalds <[email protected]>
mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
Ben Hutchings <[email protected]>
arm/mm: Convert to using lock_mm_and_find_vma()
Ben Hutchings <[email protected]>
riscv/mm: Convert to using lock_mm_and_find_vma()
Ben Hutchings <[email protected]>
mips/mm: Convert to using lock_mm_and_find_vma()
Michael Ellerman <[email protected]>
powerpc/mm: Convert to using lock_mm_and_find_vma()
Linus Torvalds <[email protected]>
arm64/mm: Convert to using lock_mm_and_find_vma()
Linus Torvalds <[email protected]>
mm: make the page fault mmap locking killable
Linus Torvalds <[email protected]>
mm: introduce new 'lock_mm_and_find_vma()' page fault helper
Peng Zhang <[email protected]>
maple_tree: fix potential out-of-bounds access in mas_wr_end_piv()
Oliver Hartkopp <[email protected]>
can: isotp: isotp_sendmsg(): fix return error fix on TX path
Wyes Karny <[email protected]>
cpufreq: amd-pstate: Make amd-pstate EPP driver name hyphenated
Thomas Gleixner <[email protected]>
x86/smp: Cure kexec() vs. mwait_play_dead() breakage
Thomas Gleixner <[email protected]>
x86/smp: Use dedicated cache-line for mwait_play_dead()
Thomas Gleixner <[email protected]>
x86/smp: Remove pointless wmb()s from native_stop_other_cpus()
Tony Battersby <[email protected]>
x86/smp: Dont access non-existing CPUID leaf
Thomas Gleixner <[email protected]>
x86/smp: Make stop_other_cpus() more robust
Borislav Petkov (AMD) <[email protected]>
x86/microcode/AMD: Load late on both threads too
-------------
Diffstat:
Makefile | 4 +- arch/alpha/Kconfig | 1 + arch/alpha/mm/fault.c | 13 +-- arch/arc/Kconfig | 1 + arch/arc/mm/fault.c | 11 +-- arch/arm/Kconfig | 1 + arch/arm/mm/fault.c | 63 ++++----------- arch/arm64/Kconfig | 1 + arch/arm64/mm/fault.c | 47 ++--------- arch/csky/Kconfig | 1 + arch/csky/mm/fault.c | 22 ++---- arch/hexagon/Kconfig | 1 + arch/hexagon/mm/vm_fault.c | 18 +---- arch/ia64/mm/fault.c | 36 ++------- arch/loongarch/Kconfig | 1 + arch/loongarch/mm/fault.c | 16 ++-- arch/m68k/mm/fault.c | 9 ++- arch/microblaze/mm/fault.c | 5 +- arch/mips/Kconfig | 1 + arch/mips/mm/fault.c | 12 +-- arch/nios2/Kconfig | 1 + arch/nios2/mm/fault.c | 17 +--- arch/openrisc/mm/fault.c | 5 +- arch/parisc/mm/fault.c | 23 +++--- arch/powerpc/Kconfig | 1 + arch/powerpc/mm/copro_fault.c | 14 +--- arch/powerpc/mm/fault.c | 39 +-------- arch/riscv/Kconfig | 1 + arch/riscv/mm/fault.c | 31 +++----- arch/s390/mm/fault.c | 5 +- arch/sh/Kconfig | 1 + arch/sh/mm/fault.c | 17 +--- arch/sparc/Kconfig | 1 + arch/sparc/mm/fault_32.c | 32 ++------ arch/sparc/mm/fault_64.c | 8 +- arch/um/kernel/trap.c | 11 +-- arch/x86/Kconfig | 1 + arch/x86/include/asm/cpu.h | 2 + arch/x86/include/asm/smp.h | 2 + arch/x86/kernel/cpu/microcode/amd.c | 2 +- arch/x86/kernel/process.c | 28 ++++++- arch/x86/kernel/smp.c | 73 ++++++++++------- arch/x86/kernel/smpboot.c | 81 ++++++++++++++++--- arch/x86/mm/fault.c | 52 +----------- arch/xtensa/Kconfig | 1 + arch/xtensa/mm/fault.c | 14 +--- drivers/cpufreq/amd-pstate.c | 2 +- drivers/hid/hid-logitech-hidpp.c | 2 +- drivers/hid/hidraw.c | 9 ++- drivers/hid/wacom_wac.c | 6 +- drivers/hid/wacom_wac.h | 2 +- drivers/iommu/amd/iommu_v2.c | 4 +- drivers/iommu/iommu-sva.c | 2 +- drivers/thermal/mediatek/auxadc_thermal.c | 14 +--- drivers/video/fbdev/core/sysimgblt.c | 2 +- fs/binfmt_elf.c | 6 +- fs/exec.c | 38 +++++---- include/linux/mm.h | 16 ++-- lib/maple_tree.c | 11 +-- mm/Kconfig | 4 + mm/gup.c | 14 +++- mm/khugepaged.c | 7 +- mm/memory.c | 127 ++++++++++++++++++++++++++++++ mm/mmap.c | 121 ++++++++++++++++++++++++---- mm/nommu.c | 17 ++-- net/can/isotp.c | 5 +- 66 files changed, 605 insertions(+), 531 deletions(-)
Greg Kroah-Hartman
maintainerPATCH 1/28 x86/microcode/AMD: Load late on both threads too
From: Borislav Petkov (AMD) <[email protected]>
commit a32b0f0db3f396f1c9be2fe621e77c09ec3d8e7d upstream.
Do the same as early loading - load on both threads.
--- arch/x86/kernel/cpu/microcode/amd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/kernel/cpu/microcode/amd.c +1 -1
@@ -705,7 +705,7 @@ static enum ucode_state apply_microcode_rdmsr (MSR_AMD64_PATCH_LEVEL , rev, dummy);/* need to apply patch? */ -if (rev >= mc_amd->hdr.patch_id) { +if (rev > mc_amd->hdr.patch_id) { ret =UCODE_OK ; goto out; }
Greg Kroah-Hartman
maintainerPATCH 2/28 x86/smp: Make stop_other_cpus() more robust
In reply to Greg Kroah-HartmanFrom: Thomas Gleixner <[email protected]>
commit 1f5e7eb7868e42227ac426c96d437117e6e06e8e upstream.
Tony reported intermittent lockups on poweroff. His analysis identified the wbinvd() in stop_this_cpu() as the culprit. This was added to ensure that on SME enabled machines a kexec() does not leave any stale data in the caches when switching from encrypted to non-encrypted mode or vice versa.
That wbinvd() is conditional on the SME feature bit which is read directly from CPUID. But that readout does not check whether the CPUID leaf is available or not. If it's not available the CPU will return the value of the highest supported leaf instead. Depending on the content the "SME" bit might be set or not.
That's incorrect but harmless. Making the CPUID readout conditional makes the observed hangs go away, but it does not fix the underlying problem:
CPU0 CPU1
stop_other_cpus()
send_IPIs(REBOOT); stop_this_cpu()
while (num_online_cpus() > 1); set_online(false);
proceed... -> hang
wbinvd()
WBINVD is an expensive operation and if multiple CPUs issue it at the same time the resulting delays are even larger.
But CPU0 already observed num_online_cpus() going down to 1 and proceeds which causes the system to hang.
This issue exists independent of WBINVD, but the delays caused by WBINVD make it more prominent.
Make this more robust by adding a cpumask which is initialized to the online CPU mask before sending the IPIs and CPUs clear their bit in stop_this_cpu() after the WBINVD completed. Check for that cpumask to become empty in stop_other_cpus() instead of watching num_online_cpus().
The cpumask cannot plug all holes either, but it's better than a raw counter and allows to restrict the NMI fallback IPI to be sent only the CPUs which have not reported within the timeout window.
--- arch/x86/include/asm/cpu.h | 2 + arch/x86/kernel/process.c | 23 +++++++++++++++- arch/x86/kernel/smp.c | 62 +++++++++++++++++++++++++++++---------------- 3 files changed, 64 insertions(+), 23 deletions(-)
arch/x86/include/asm/cpu.h +2 -0
@@ -98,4 +98,6 @@ extern u64 x86_read_arch_cap_msr(void);int intel_find_matching_signature (void *mc,unsigned int csig,int cpf);int intel_microcode_sanity_check (void *mc,bool print_err,int hdr_type); +extern struct cpumask cpus_stop_mask; +#endif /* _ASM_X86_CPU_H */
arch/x86/kernel/process.c +21 -2
@@ -759,13 +759,23 @@ bool xen_set_default_idle(void) }#endif +struct cpumask cpus_stop_mask; +void __noreturn stop_this_cpu (void *dummy) { +unsigned int cpu =smp_processor_id (); +local_irq_disable (); +/* -* Remove this CPU: +* Remove this CPU from the online mask and disable it +* unconditionally. This might be redundant in case that the reboot +* vector was handled late and stop_other_cpus() sent an NMI. +* +* According to SDM and APM NMIs can be accepted even after soft +* disabling the local APIC. */ -set_cpu_online (smp_processor_id (), false); +set_cpu_online (cpu, false);disable_local_APIC ();mcheck_cpu_clear (this_cpu_ptr (&cpu_info));
@@ -783,6 +793,15 @@ void __noreturn stop_this_cpu(void *dumm*/ if (cpuid_eax (0x8000001f ) &BIT (0 ))native_wbinvd (); + +/* +* This brings a cache line back and dirties it, but +* native_stop_other_cpus() will overwrite cpus_stop_mask after it +* observed that all CPUs reported stop. This write will invalidate +* the related cache line on this CPU. +*/ +cpumask_clear_cpu (cpu, &cpus_stop_mask); +for (;;) {/* * Use native_halt() so that memory contents don't change
arch/x86/kernel/smp.c +41 -21
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Greg Kroah-Hartman
maintainerPATCH 3/28 x86/smp: Dont access non-existing CPUID leaf
In reply to Greg Kroah-HartmanFrom: Tony Battersby <[email protected]>
commit 9b040453d4440659f33dc6f0aa26af418ebfe70b upstream.
stop_this_cpu() tests CPUID leaf 0x8000001f::EAX unconditionally. Intel CPUs return the content of the highest supported leaf when a non-existing leaf is read, while AMD CPUs return all zeros for unsupported leafs.
So the result of the test on Intel CPUs is lottery.
While harmless it's incorrect and causes the conditional wbinvd() to be issued where not required.
Check whether the leaf is supported before reading it.
[ tglx: Adjusted changelog ]
--- arch/x86/kernel/process.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
arch/x86/kernel/process.c +3 -2
@@ -763,6 +763,7 @@ struct cpumask cpus_stop_mask;void __noreturn stop_this_cpu (void *dummy) { +struct cpuinfo_x86 *c =this_cpu_ptr (&cpu_info);unsigned int cpu =smp_processor_id ();local_irq_disable ();
@@ -777,7 +778,7 @@ void __noreturn stop_this_cpu(void *dumm*/ set_cpu_online (cpu, false);disable_local_APIC (); -mcheck_cpu_clear (this_cpu_ptr (&cpu_info)); +mcheck_cpu_clear (c);/* * Use wbinvd on processors that support SME. This provides support
@@ -791,7 +792,7 @@ void __noreturn stop_this_cpu(void *dumm* Test the CPUID bit directly because the machine might've cleared * X86_FEATURE_SME due to cmdline options. */ -if (cpuid_eax (0x8000001f ) &BIT (0 )) +if (c->extended_cpuid_level >=0x8000001f && (cpuid_eax (0x8000001f ) &BIT (0 )))native_wbinvd ();/*
Greg Kroah-Hartman
maintainerPATCH 4/28 x86/smp: Remove pointless wmb()s from native_stop_other_cpus()
In reply to Greg Kroah-HartmanFrom: Thomas Gleixner <[email protected]>
commit 2affa6d6db28855e6340b060b809c23477aa546e upstream.
The wmb()s before sending the IPIs are not synchronizing anything.
If at all then the apic IPI functions have to provide or act as appropriate barriers.
Remove these cargo cult barriers which have no explanation of what they are synchronizing.
--- arch/x86/kernel/smp.c | 6 ------ 1 file changed, 6 deletions(-)
arch/x86/kernel/smp.c +0 -6
@@ -184,9 +184,6 @@ static void native_stop_other_cpus(int wcpumask_clear_cpu (cpu, &cpus_stop_mask);if (!cpumask_empty (&cpus_stop_mask)) { -/* sync above data before sending IRQ */ -wmb (); -apic_send_IPI_allbutself (REBOOT_VECTOR );/*
@@ -208,9 +205,6 @@ static void native_stop_other_cpus(int w* CPUs to stop. */ if (!smp_no_nmi_ipi && !register_stop_handler ()) { -/* Sync above data before sending IRQ */ -wmb (); -pr_emerg ("Shutting down cpus with NMI\n" );for_each_cpu (cpu, &cpus_stop_mask)
Greg Kroah-Hartman
maintainerPATCH 5/28 x86/smp: Use dedicated cache-line for mwait_play_dead()
In reply to Greg Kroah-HartmanFrom: Thomas Gleixner <[email protected]>
commit f9c9987bf52f4e42e940ae217333ebb5a4c3b506 upstream.
Monitoring idletask::thread_info::flags in mwait_play_dead() has been an obvious choice as all what is needed is a cache line which is not written by other CPUs.
But there is a use case where a "dead" CPU needs to be brought out of
MWAIT: kexec().
This is required as kexec() can overwrite text, pagetables, stacks and the monitored cacheline of the original kernel. The latter causes MWAIT to resume execution which obviously causes havoc on the kexec kernel which results usually in triple faults.
Use a dedicated per CPU storage to prepare for that.
--- arch/x86/kernel/smpboot.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
arch/x86/kernel/smpboot.c +14 -10
@@ -101,6 +101,17 @@ EXPORT_PER_CPU_SYMBOL(cpu_die_map); DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);EXPORT_PER_CPU_SYMBOL (cpu_info); +struct mwait_cpu_dead { +unsigned int control; +unsigned int status; +}; + +/* +* Cache line aligned data for mwait_play_dead(). Separate on purpose so +* that it's unlikely to be touched by other CPUs. +*/ +static DEFINE_PER_CPU_ALIGNED(struct mwait_cpu_dead, mwait_cpu_dead); +/* Logical package management. We might want to allocate that dynamically */ unsigned int __max_logical_packages__read_mostly ;EXPORT_SYMBOL (__max_logical_packages);
@@ -1758,10 +1769,10 @@ EXPORT_SYMBOL_GPL(cond_wakeup_cpu0);*/ static inline void mwait_play_dead (void ) { +struct mwait_cpu_dead *md =this_cpu_ptr (&mwait_cpu_dead);unsigned int eax, ebx, ecx, edx;unsigned int highest_cstate =0 ;unsigned int highest_subcstate =0 ; -void *mwait_ptr;int i; if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
@@ -1796,13 +1807,6 @@ static inline void mwait_play_dead(void) (highest_subcstate -1 ); } -/* -* This should be a memory location in a cache line which is -* unlikely to be touched by other processors. The actual -* content is immaterial as it is not actually modified in any way. -*/ - mwait_ptr = ¤t_thread_info ()->flags; -wbinvd ();while (1 ) {
@@ -1814,9 +1818,9 @@ static inline void mwait_play_dead(void)* case where we return around the loop. */ mb (); -clflush (mwait_ptr); +clflush (md);mb (); -__monitor (mwait_ptr,0 ,0 ); +__monitor (md,0 ,0 );mb ();__mwait (eax,0 );
Greg Kroah-Hartman
maintainerPATCH 6/28 x86/smp: Cure kexec() vs. mwait_play_dead() breakage
In reply to Greg Kroah-HartmanFrom: Thomas Gleixner <[email protected]>
commit d7893093a7417527c0d73c9832244e65c9d0114f upstream.
TLDR: It's a mess.
When kexec() is executed on a system with offline CPUs, which are parked in mwait_play_dead() it can end up in a triple fault during the bootup of the kexec kernel or cause hard to diagnose data corruption.
The reason is that kexec() eventually overwrites the previous kernel's text, page tables, data and stack. If it writes to the cache line which is monitored by a previously offlined CPU, MWAIT resumes execution and ends up executing the wrong text, dereferencing overwritten page tables or corrupting the kexec kernels data.
Cure this by bringing the offlined CPUs out of MWAIT into HLT.
Write to the monitored cache line of each offline CPU, which makes MWAIT resume execution. The written control word tells the offlined CPUs to issue HLT, which does not have the MWAIT problem.
That does not help, if a stray NMI, MCE or SMI hits the offlined CPUs as those make it come out of HLT.
A follow up change will put them into INIT, which protects at least against NMI and SMI.
--- arch/x86/include/asm/smp.h | 2 + arch/x86/kernel/smp.c | 5 +++ arch/x86/kernel/smpboot.c | 59 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 66 insertions(+)
arch/x86/include/asm/smp.h +2 -0
@@ -132,6 +132,8 @@ void wbinvd_on_cpu(int cpu);int wbinvd_on_all_cpus (void );void cond_wakeup_cpu0 (void ); +void smp_kick_mwait_play_dead (void ); +void native_smp_send_reschedule (int cpu);void native_send_call_func_ipi (const struct cpumask *mask);void native_send_call_func_single_ipi (int cpu);
arch/x86/kernel/smp.c +5 -0
@@ -21,6 +21,7 @@#include <linux/interrupt.h> #include <linux/cpu.h> #include <linux/gfp.h> +#include <linux/kexec.h> #include <asm/mtrr.h> #include <asm/tlbflush.h>
@@ -157,6 +158,10 @@ static void native_stop_other_cpus(int wif (atomic_cmpxchg (&stopping_cpu,-1 , cpu) !=-1 )return ; +/* For kexec, ensure that offline CPUs are out of MWAIT and in HLT */ +if (kexec_in_progress) +smp_kick_mwait_play_dead (); +/* * 1) Send an IPI on the reboot vector to all other CPUs. *
arch/x86/kernel/smpboot.c +59 -0
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Greg Kroah-Hartman
maintainerPATCH 7/28 cpufreq: amd-pstate: Make amd-pstate EPP driver name hyphenated
In reply to Greg Kroah-HartmanFrom: Wyes Karny <[email protected]>
commit f4aad639302a07454dcb23b408dcadf8a9efb031 upstream.
amd-pstate passive mode driver is hyphenated. So make amd-pstate active mode driver consistent with that rename "amd_pstate_epp" to "amd-pstate-epp".
--- drivers/cpufreq/amd-pstate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/cpufreq/amd-pstate.c +1 -1
@@ -1356,7 +1356,7 @@ static struct cpufreq_driver amd_pstate_ .online = amd_pstate_epp_cpu_online, .suspend = amd_pstate_epp_suspend, .resume = amd_pstate_epp_resume, - .name = "amd_pstate_epp", + .name = "amd-pstate-epp", .attr = amd_pstate_epp_attr, };
Greg Kroah-Hartman
maintainerPATCH 8/28 can: isotp: isotp_sendmsg(): fix return error fix on TX path
In reply to Greg Kroah-HartmanFrom: Oliver Hartkopp <[email protected]>
commit e38910c0072b541a91954682c8b074a93e57c09b upstream.
With commit d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return error on FC timeout on TX path") the missing correct return value in the case of a protocol error was introduced.
But the way the error value has been read and sent to the user space does not follow the common scheme to clear the error after reading which is provided by the sock_error() function. This leads to an error report at the following write() attempt although everything should be working.
--- net/can/isotp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
net/can/isotp.c +3 -2
@@ -1112,8 +1112,9 @@ wait_free_buffer:if (err) goto err_event_drop; -if (sk->sk_err) -return -sk->sk_err; + err =sock_error (sk); +if (err) +return err; }return size;
Greg Kroah-Hartman
maintainerPATCH 9/28 maple_tree: fix potential out-of-bounds access in mas_wr_end_piv()
In reply to Greg Kroah-HartmanFrom: Peng Zhang <[email protected]>
commit cd00dd2585c4158e81fdfac0bbcc0446afbad26d upstream.
Check the write offset end bounds before using it as the offset into the pivot array. This avoids a possible out-of-bounds access on the pivot array if the write extends to the last slot in the node, in which case the node maximum should be used as the end pivot.
akpm: this doesn't affect any current callers, but new users of mapletree may encounter this problem if backported into earlier kernels, so let's fix it in -stable kernels in case of this.
--- lib/maple_tree.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
lib/maple_tree.c +6 -5
@@ -4263,11 +4263,13 @@ done:static inline void mas_wr_end_piv (struct ma_wr_state *wr_mas) { -while ((wr_mas->mas->last > wr_mas->end_piv) && - (wr_mas->offset_end < wr_mas->node_end)) - wr_mas->end_piv = wr_mas->pivots[++wr_mas->offset_end]; +while ((wr_mas->offset_end < wr_mas->node_end) && + (wr_mas->mas->last > wr_mas->pivots[wr_mas->offset_end])) + wr_mas->offset_end++; -if (wr_mas->mas->last > wr_mas->end_piv) +if (wr_mas->offset_end < wr_mas->node_end) + wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end]; +else wr_mas->end_piv = wr_mas->mas->max; }
@@ -4424,7 +4426,6 @@ static inline void *mas_wr_store_entry(s }/* At this point, we are at the leaf node that needs to be altered. */ - wr_mas->end_piv = wr_mas->r_max;mas_wr_end_piv (wr_mas);if (!wr_mas->entry)
Greg Kroah-Hartman
maintainerPATCH 10/28 mm: introduce new lock_mm_and_find_vma() page fault helper
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit c2508ec5a58db67093f4fb8bf89a9a7c53a109e9 upstream.
.. and make x86 use it.
This basically extracts the existing x86 "find and expand faulting vma" code, but extends it to also take the mmap lock for writing in case we actually do need to expand the vma.
We've historically short-circuited that case, and have some rather ugly special logic to serialize the stack segment expansion (since we only hold the mmap lock for reading) that doesn't match the normal VM locking.
That slight violation of locking worked well, right up until it didn't:
the maple tree code really does want proper locking even for simple extension of an existing vma.
So extract the code for "look up the vma of the fault" from x86, fix it up to do the necessary write locking, and make it available as a helper function for other architectures that can use the common helper.
Note: I say "common helper", but it really only handles the normal stack-grows-down case. Which is all architectures except for PA-RISC and IA64. So some rare architectures can't use the helper, but if they care they'll just need to open-code this logic.
It's also worth pointing out that this code really would like to have an optimistic "mmap_upgrade_trylock()" to make it quicker to go from a read-lock (for the common case) to taking the write lock (for having to extend the vma) in the normal single-threaded situation where there is no other locking activity.
But that _is_ all the very uncommon special case, so while it would be nice to have such an operation, it probably doesn't matter in reality. I did put in the skeleton code for such a possible future expansion, even if it only acts as pseudo-documentation for what we're doing.
--- arch/x86/Kconfig | 1 arch/x86/mm/fault.c | 52 ---------------------- include/linux/mm.h | 2 mm/Kconfig | 4 + mm/memory.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 130 insertions(+), 50 deletions(-)
arch/x86/Kconfig +1 -0
@@ -276,6 +276,7 @@ config X86 select HAVE_GENERIC_VDSO select HOTPLUG_SMT if SMP select IRQ_FORCED_THREADING + select LOCK_MM_AND_FIND_VMA select NEED_PER_CPU_EMBED_FIRST_CHUNK select NEED_PER_CPU_PAGE_FIRST_CHUNK select NEED_SG_DMA_LENGTH
arch/x86/mm/fault.c +2 -50
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include/linux/mm.h +2 -0
@@ -2325,6 +2325,8 @@ void unmap_mapping_pages(struct address_ pgoff_t start, pgoff_t nr, bool even_cows);void unmap_mapping_range (struct address_space *mapping,loff_t const holebegin,loff_t const holelen,int even_cows); +struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, +unsigned long address,struct pt_regs *regs);#else static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, unsigned int flags,
mm/Kconfig +4 -0
@@ -1206,6 +1206,10 @@ config PER_VMA_LOCK This feature allows locking each virtual memory area separately when handling page faults instead of taking mmap_lock. +config LOCK_MM_AND_FIND_VMA + bool + depends on !STACK_GROWSUP + source "mm/damon/Kconfig" endmenu
mm/memory.c +121 -0
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Greg Kroah-Hartman
maintainerPATCH 11/28 mm: make the page fault mmap locking killable
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit eda0047296a16d65a7f2bc60a408f70d178b2014 upstream.
This is done as a separate patch from introducing the new lock_mm_and_find_vma() helper, because while it's an obvious change, it's not what x86 used to do in this area.
We already abort the page fault on fatal signals anyway, so why should we wait for the mmap lock only to then abort later? With the new helper function that returns without the lock held on failure anyway, this is particularly easy and straightforward.
--- mm/memory.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
mm/memory.c +2 -4
@@ -5279,8 +5279,7 @@ static inline bool get_mmap_lock_carefulreturn false; } -mmap_read_lock (mm); -return true; +return !mmap_read_lock_killable (mm); }static inline bool mmap_upgrade_trylock (struct mm_struct *mm)
@@ -5304,8 +5303,7 @@ static inline bool upgrade_mmap_lock_carif (!search_exception_tables (ip))return false; } -mmap_write_lock (mm); -return true; +return !mmap_write_lock_killable (mm); }/*
Greg Kroah-Hartman
maintainerPATCH 12/28 arm64/mm: Convert to using lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit ae870a68b5d13d67cf4f18d47bb01ee3fee40acb upstream.
This converts arm64 to use the new page fault helper. It was very straightforward, but still needed a fix for the "obvious" conversion I initially did. Thanks to Suren for the fix and testing.
--- arch/arm64/Kconfig | 1 + arch/arm64/mm/fault.c | 47 ++++++++--------------------------------------- 2 files changed, 9 insertions(+), 39 deletions(-)
arch/arm64/Kconfig +1 -0
@@ -225,6 +225,7 @@ config ARM64 select IRQ_DOMAIN select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE select NEED_SG_DMA_LENGTH
arch/arm64/mm/fault.c +8 -39
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Greg Kroah-Hartman
maintainerPATCH 13/28 powerpc/mm: Convert to using lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Michael Ellerman <[email protected]>
commit e6fe228c4ffafdfc970cf6d46883a1f481baf7ea upstream.
--- arch/powerpc/Kconfig | 1 + arch/powerpc/mm/fault.c | 41 ++++------------------------------------- 2 files changed, 5 insertions(+), 37 deletions(-)
arch/powerpc/Kconfig +1 -0
@@ -278,6 +278,7 @@ config PPC select IRQ_DOMAIN select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN && MODULES + select LOCK_MM_AND_FIND_VMA select MMU_GATHER_PAGE_SIZE select MMU_GATHER_RCU_TABLE_FREE select MMU_GATHER_MERGE_VMAS
arch/powerpc/mm/fault.c +4 -37
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Greg Kroah-Hartman
maintainerPATCH 14/28 mips/mm: Convert to using lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Ben Hutchings <[email protected]>
commit 4bce37a68ff884e821a02a731897a8119e0c37b7 upstream.
--- arch/mips/Kconfig | 1 + arch/mips/mm/fault.c | 12 ++---------- 2 files changed, 3 insertions(+), 10 deletions(-)
arch/mips/Kconfig +1 -0
@@ -91,6 +91,7 @@ config MIPS select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP select IRQ_FORCED_THREADING select ISA if EISA + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_REL if MODULES select MODULES_USE_ELF_RELA if MODULES && 64BIT select PERF_USE_VMALLOC
arch/mips/mm/fault.c +2 -10
@@ -99,21 +99,13 @@ static void __do_page_fault(struct pt_reperf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; + goto bad_area_nosemaphore;/* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: si_code =SEGV_ACCERR ;if (write) {
Greg Kroah-Hartman
maintainerPATCH 15/28 riscv/mm: Convert to using lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Ben Hutchings <[email protected]>
commit 7267ef7b0b77f4ed23b7b3c87d8eca7bd9c2d007 upstream.
--- arch/riscv/Kconfig | 1 + arch/riscv/mm/fault.c | 31 +++++++++++++------------------ 2 files changed, 14 insertions(+), 18 deletions(-)
arch/riscv/Kconfig +1 -0
@@ -126,6 +126,7 @@ config RISCV select IRQ_DOMAIN select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA if MODULES select MODULE_SECTIONS if MODULES select OF
arch/riscv/mm/fault.c +13 -18
@@ -84,13 +84,13 @@ static inline void mm_fault_error(structBUG (); } -static inline void bad_area (struct pt_regs *regs,struct mm_struct *mm,int code,unsigned long addr) +static inline void +bad_area_nosemaphore (struct pt_regs *regs,int code,unsigned long addr) {/* * Something tried to access memory that isn't in our memory map. * Fix it, but check if it's kernel or user first. */ -mmap_read_unlock (mm);/* User mode accesses just cause a SIGSEGV */ if (user_mode (regs)) {do_trap (regs,SIGSEGV , code, addr);
@@ -100,6 +100,15 @@ static inline void bad_area(struct pt_reno_context (regs, addr); } +static inline void +bad_area (struct pt_regs *regs,struct mm_struct *mm,int code, +unsigned long addr) +{ +mmap_read_unlock (mm); + +bad_area_nosemaphore (regs, code, addr); +} +static inline void vmalloc_fault (struct pt_regs *regs,int code,unsigned long addr) {pgd_t *pgd, *pgd_k;
@@ -287,23 +296,10 @@ void handle_page_fault(struct pt_regs *relse if (cause ==EXC_INST_PAGE_FAULT ) flags |=FAULT_FLAG_INSTRUCTION ; retry: -mmap_read_lock (mm); - vma =find_vma (mm, addr); + vma =lock_mm_and_find_vma (mm, addr, regs);if (unlikely (!vma)) { tsk->thread.bad_cause = cause; -bad_area (regs, mm, code, addr); -return ; - } -if (likely (vma->vm_start <= addr)) - goto good_area; -if (unlikely (!(vma->vm_flags &VM_GROWSDOWN ))) { - tsk->thread.bad_cause = cause; -bad_area (regs, mm, code, addr); -return ; - } -if (unlikely (expand_stack (vma, addr))) { - tsk->thread.bad_cause = cause; -bad_area (regs, mm, code, addr); +bad_area_nosemaphore (regs, code, addr);return ; }
@@ -311,7 +307,6 @@ retry:* Ok, we have a good vm_area for this memory access, so * we can handle it. */ -good_area: code =SEGV_ACCERR ;if (unlikely (access_error (cause, vma))) {
Greg Kroah-Hartman
maintainerPATCH 16/28 arm/mm: Convert to using lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Ben Hutchings <[email protected]>
commit 8b35ca3e45e35a26a21427f35d4093606e93ad0a upstream.
arm has an additional check for address < FIRST_USER_ADDRESS before expanding the stack. Since FIRST_USER_ADDRESS is defined everywhere (generally as 0), move that check to the generic expand_downwards().
--- arch/arm/Kconfig | 1 arch/arm/mm/fault.c | 63 +++++++++++----------------------------------------- mm/mmap.c | 2 - 3 files changed, 16 insertions(+), 50 deletions(-)
arch/arm/Kconfig +1 -0
@@ -125,6 +125,7 @@ config ARM select HAVE_UID16 select HAVE_VIRT_CPU_ACCOUNTING_GEN select IRQ_FORCED_THREADING + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_REL select NEED_DMA_MAP_STATE select OF_EARLY_FLATTREE if OF
arch/arm/mm/fault.c +14 -49
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mm/mmap.c +1 -1
@@ -2036,7 +2036,7 @@ int expand_downwards(struct vm_area_struint error =0 ; address &=PAGE_MASK ; -if (address < mmap_min_addr) +if (address < mmap_min_addr || address <FIRST_USER_ADDRESS )return -EPERM ;/* Enforce stack_guard_gap */
Greg Kroah-Hartman
maintainerPATCH 17/28 mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit a050ba1e7422f2cc60ff8bfde3f96d34d00cb585 upstream.
This does the simple pattern conversion of alpha, arc, csky, hexagon, loongarch, nios2, sh, sparc32, and xtensa to the lock_mm_and_find_vma() helper. They all have the regular fault handling pattern without odd special cases.
The remaining architectures all have something that keeps us from a straightforward conversion: ia64 and parisc have stacks that can grow both up as well as down (and ia64 has special address region checks).
And m68k, microblaze, openrisc, sparc64, and um end up having extra rules about only expanding the stack down a limited amount below the user space stack pointer. That is something that x86 used to do too (long long ago), and it probably could just be skipped, but it still makes the conversion less than trivial.
Note that this conversion was done manually and with the exception of alpha without any build testing, because I have a fairly limited cross- building environment. The cases are all simple, and I went through the changes several times, but...
--- arch/alpha/Kconfig | 1 + arch/alpha/mm/fault.c | 13 +++---------- arch/arc/Kconfig | 1 + arch/arc/mm/fault.c | 11 +++-------- arch/csky/Kconfig | 1 + arch/csky/mm/fault.c | 22 +++++----------------- arch/hexagon/Kconfig | 1 + arch/hexagon/mm/vm_fault.c | 18 ++++-------------- arch/loongarch/Kconfig | 1 + arch/loongarch/mm/fault.c | 16 ++++++---------- arch/nios2/Kconfig | 1 + arch/nios2/mm/fault.c | 17 ++--------------- arch/sh/Kconfig | 1 + arch/sh/mm/fault.c | 17 ++--------------- arch/sparc/Kconfig | 1 + arch/sparc/mm/fault_32.c | 32 ++++++++------------------------ arch/xtensa/Kconfig | 1 + arch/xtensa/mm/fault.c | 14 +++----------- 18 files changed, 45 insertions(+), 124 deletions(-)
arch/alpha/Kconfig +1 -0
@@ -30,6 +30,7 @@ config ALPHA select HAS_IOPORT select HAVE_ARCH_AUDITSYSCALL select HAVE_MOD_ARCH_SPECIFIC + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select ODD_RT_SIGACTION select OLD_SIGSUSPEND
arch/alpha/mm/fault.c +3 -10
@@ -119,20 +119,12 @@ do_page_fault(unsigned long address, uns flags |=FAULT_FLAG_USER ;perf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; + goto bad_area_nosemaphore;/* Ok, we have a good vm_area for this memory access, so we can handle it. */ - good_area: si_code =SEGV_ACCERR ;if (cause <0 ) {if (!(vma->vm_flags &VM_EXEC ))
@@ -192,6 +184,7 @@ retry: bad_area:mmap_read_unlock (mm); + bad_area_nosemaphore:if (user_mode (regs)) goto do_sigsegv;
arch/arc/Kconfig +1 -0
@@ -41,6 +41,7 @@ config ARC select HAVE_PERF_EVENTS select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select OF select OF_EARLY_FLATTREE
arch/arc/mm/fault.c +3 -8
@@ -113,15 +113,9 @@ void do_page_fault(unsigned long addressperf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (unlikely (address < vma->vm_start)) { -if (!(vma->vm_flags &VM_GROWSDOWN ) ||expand_stack (vma, address)) - goto bad_area; - } + goto bad_area_nosemaphore;/* * vm_area is good, now check permissions for this memory access
@@ -161,6 +155,7 @@ retry: bad_area:mmap_read_unlock (mm); +bad_area_nosemaphore:/* * Major/minor page fault accounting * (in case of retry we only land here once)
arch/csky/Kconfig +1 -0
@@ -96,6 +96,7 @@ config CSKY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS + select LOCK_MM_AND_FIND_VMA select MAY_HAVE_SPARSE_IRQ select MODULES_USE_ELF_RELA if MODULES select OF
arch/csky/mm/fault.c +5 -17
@@ -97,13 +97,12 @@ static inline void mm_fault_error(structBUG (); } -static inline void bad_area (struct pt_regs *regs,struct mm_struct *mm,int code,unsigned long addr) +static inline void bad_area_nosemaphore (struct pt_regs *regs,struct mm_struct *mm,int code,unsigned long addr) {/* * Something tried to access memory that isn't in our memory map. * Fix it, but check if it's kernel or user first. */ -mmap_read_unlock (mm);/* User mode accesses just cause a SIGSEGV */ if (user_mode (regs)) {do_trap (regs,SIGSEGV , code, addr);
@@ -238,20 +237,9 @@ asmlinkage void do_page_fault(struct pt_if (is_write (regs)) flags |=FAULT_FLAG_WRITE ; retry: -mmap_read_lock (mm); - vma =find_vma (mm, addr); + vma =lock_mm_and_find_vma (mm, address, regs);if (unlikely (!vma)) { -bad_area (regs, mm, code, addr); -return ; - } -if (likely (vma->vm_start <= addr)) - goto good_area; -if (unlikely (!(vma->vm_flags &VM_GROWSDOWN ))) { -bad_area (regs, mm, code, addr); -return ; - } -if (unlikely (expand_stack (vma, addr))) { -bad_area (regs, mm, code, addr); +bad_area_nosemaphore (regs, mm, code, addr);return ; }
@@ -259,11 +247,11 @@ retry:* Ok, we have a good vm_area for this memory access, so * we can handle it. */ -good_area: code =SEGV_ACCERR ;if (unlikely (access_error (regs, vma))) { -bad_area (regs, mm, code, addr); +mmap_read_unlock (mm); +bad_area_nosemaphore (regs, mm, code, addr);return ; }
arch/hexagon/Kconfig +1 -0
@@ -28,6 +28,7 @@ config HEXAGON select GENERIC_SMP_IDLE_THREAD select STACKTRACE_SUPPORT select GENERIC_CLOCKEVENTS_BROADCAST + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select GENERIC_CPU_DEVICES select ARCH_WANT_LD_ORPHAN_WARN
arch/hexagon/mm/vm_fault.c +4 -14
@@ -57,21 +57,10 @@ void do_page_fault(unsigned long addressperf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - vma =find_vma (mm, address); -if (!vma) - goto bad_area; + vma =lock_mm_and_find_vma (mm, address, regs); +if (unlikely (!vma)) + goto bad_area_nosemaphore; -if (vma->vm_start <= address) - goto good_area; - -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; - -if (expand_stack (vma, address)) - goto bad_area; - -good_area:/* Address space is OK. Now check access rights. */ si_code =SEGV_ACCERR ;
@@ -143,6 +132,7 @@ good_area: bad_area:mmap_read_unlock (mm); +bad_area_nosemaphore:if (user_mode (regs)) {force_sig_fault (SIGSEGV , si_code, (void __user *)address);return ;
arch/loongarch/Kconfig +1 -0
@@ -130,6 +130,7 @@ config LOONGARCH select HAVE_VIRT_CPU_ACCOUNTING_GEN if !SMP select IRQ_FORCED_THREADING select IRQ_LOONGARCH_CPU + select LOCK_MM_AND_FIND_VMA select MMU_GATHER_MERGE_VMAS if MMU select MODULES_USE_ELF_RELA if MODULES select NEED_PER_CPU_EMBED_FIRST_CHUNK
arch/loongarch/mm/fault.c +6 -10
@@ -169,22 +169,18 @@ static void __kprobes __do_page_fault(stperf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - vma =find_vma (mm, address); -if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (!expand_stack (vma, address)) - goto good_area; + vma =lock_mm_and_find_vma (mm, address, regs); +if (unlikely (!vma)) + goto bad_area_nosemaphore; + goto good_area; +/* * Something tried to access memory that isn't in our memory map.. * Fix it, but check if it's kernel or user first.. */ bad_area:mmap_read_unlock (mm); +bad_area_nosemaphore:do_sigsegv (regs, write, address, si_code);return ;
arch/nios2/Kconfig +1 -0
@@ -16,6 +16,7 @@ config NIOS2 select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_KGDB select IRQ_DOMAIN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select OF select OF_EARLY_FLATTREE
arch/nios2/mm/fault.c +2 -15
@@ -86,27 +86,14 @@ asmlinkage void do_page_fault(struct pt_perf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); -if (!mmap_read_trylock (mm)) { -if (!user_mode (regs) && !search_exception_tables (regs->ea)) - goto bad_area_nosemaphore; retry: -mmap_read_lock (mm); - } - - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; + goto bad_area_nosemaphore;/* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: code =SEGV_ACCERR ;switch (cause) {
arch/sh/Kconfig +1 -0
@@ -59,6 +59,7 @@ config SUPERH select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select IRQ_FORCED_THREADING + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select NEED_SG_DMA_LENGTH select NO_DMA if !MMU && !DMA_COHERENT
arch/sh/mm/fault.c +2 -15
@@ -439,21 +439,9 @@ asmlinkage void __kprobes do_page_fault( } retry: -mmap_read_lock (mm); - - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (unlikely (!vma)) { -bad_area (regs, error_code, address); -return ; - } -if (likely (vma->vm_start <= address)) - goto good_area; -if (unlikely (!(vma->vm_flags &VM_GROWSDOWN ))) { -bad_area (regs, error_code, address); -return ; - } -if (unlikely (expand_stack (vma, address))) { -bad_area (regs, error_code, address); +bad_area_nosemaphore (regs, error_code, address);return ; }
@@ -461,7 +449,6 @@ retry:* Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area:if (unlikely (access_error (error_code, vma))) {bad_area_access_error (regs, error_code, address);return ;
arch/sparc/Kconfig +1 -0
@@ -57,6 +57,7 @@ config SPARC32 select DMA_DIRECT_REMAP select GENERIC_ATOMIC64 select HAVE_UID16 + select LOCK_MM_AND_FIND_VMA select OLD_SIGACTION select ZONE_DMA
arch/sparc/mm/fault_32.c +8 -24
@@ -143,28 +143,19 @@ asmlinkage void do_sparc_fault(struct ptif (pagefault_disabled () || !mm) goto no_context; +if (!from_user && address >=PAGE_OFFSET ) + goto no_context; +perf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - -if (!from_user && address >=PAGE_OFFSET ) - goto bad_area; - - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; + goto bad_area_nosemaphore;/* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: code =SEGV_ACCERR ;if (write) {if (!(vma->vm_flags &VM_WRITE ))
@@ -321,17 +312,9 @@ static void force_user_fault(unsigned lo code =SEGV_MAPERR ; -mmap_read_lock (mm); - vma =find_vma (mm, address); + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; -good_area: + goto bad_area_nosemaphore; code =SEGV_ACCERR ;if (write) {if (!(vma->vm_flags &VM_WRITE ))
@@ -350,6 +333,7 @@ good_area:return ; bad_area:mmap_read_unlock (mm); +bad_area_nosemaphore:__do_fault_siginfo (code,SIGSEGV , tsk->thread.kregs, address);return ;
arch/xtensa/Kconfig +1 -0
@@ -49,6 +49,7 @@ config XTENSA select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING_GEN select IRQ_DOMAIN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select PERF_USE_VMALLOC select TRACE_IRQFLAGS_SUPPORT
arch/xtensa/mm/fault.c +3 -11
@@ -130,23 +130,14 @@ void do_page_fault(struct pt_regs *regs)perf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, address); retry: -mmap_read_lock (mm); - vma =find_vma (mm, address); - + vma =lock_mm_and_find_vma (mm, address, regs);if (!vma) - goto bad_area; -if (vma->vm_start <= address) - goto good_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; + goto bad_area_nosemaphore;/* Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: code =SEGV_ACCERR ;if (is_write) {
@@ -205,6 +196,7 @@ good_area:*/ bad_area:mmap_read_unlock (mm); +bad_area_nosemaphore:if (user_mode (regs)) {force_sig_fault (SIGSEGV , code, (void *) address);return ;
Greg Kroah-Hartman
maintainerPATCH 18/28 powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit 2cd76c50d0b41cec5c87abfcdf25b236a2793fb6 upstream.
This is one of the simple cases, except there's no pt_regs pointer. Which is fine, as lock_mm_and_find_vma() is set up to work fine with a NULL pt_regs.
Powerpc already enabled LOCK_MM_AND_FIND_VMA for the main CPU faulting, so we can just use the helper without any extra work.
--- arch/powerpc/mm/copro_fault.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)
arch/powerpc/mm/copro_fault.c +3 -11
@@ -33,19 +33,11 @@ int copro_handle_mm_fault(struct mm_struif (mm->pgd ==NULL )return -EFAULT ; -mmap_read_lock (mm); - ret = -EFAULT ; - vma =find_vma (mm, ea); + vma =lock_mm_and_find_vma (mm, ea,NULL );if (!vma) - goto out_unlock; - -if (ea < vma->vm_start) { -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto out_unlock; -if (expand_stack (vma, ea)) - goto out_unlock; - } +return -EFAULT ; + ret = -EFAULT ; is_write = dsisr &DSISR_ISSTORE ;if (is_write) {if (!(vma->vm_flags &VM_WRITE ))
Greg Kroah-Hartman
maintainerPATCH 19/28 mm: make find_extend_vma() fail if write lock not held
In reply to Greg Kroah-HartmanFrom: Liam R. Howlett <[email protected]>
commit f440fa1ac955e2898893f9301568435eb5cdfc4b upstream.
Make calls to extend_vma() and find_extend_vma() fail if the write lock is required.
To avoid making this a flag-day event, this still allows the old read-locking case for the trivial situations, and passes in a flag to say "is it write-locked". That way write-lockers can say "yes, I'm being careful", and legacy users will continue to work in all the common cases until they have been fully converted to the new world order.
--- fs/binfmt_elf.c | 6 +++--- fs/exec.c | 5 +++-- include/linux/mm.h | 10 +++++++--- mm/memory.c | 2 +- mm/mmap.c | 50 +++++++++++++++++++++++++++++++++----------------- mm/nommu.c | 3 ++- 6 files changed, 49 insertions(+), 27 deletions(-)
fs/binfmt_elf.c +3 -3
@@ -320,10 +320,10 @@ create_elf_tables(struct linux_binprm *b* Grow the stack manually; some architectures have a limit on how * far ahead a user-space access may be in order to grow the stack. */ -if (mmap_read_lock_killable (mm)) +if (mmap_write_lock_killable (mm))return -EINTR ; - vma =find_extend_vma (mm, bprm->p); -mmap_read_unlock (mm); + vma =find_extend_vma_locked (mm, bprm->p, true); +mmap_write_unlock (mm);if (!vma)return -EFAULT ;
fs/exec.c +3 -2
@@ -205,7 +205,8 @@ static struct page *get_arg_page(struct#ifdef CONFIG_STACK_GROWSUP if (write) { - ret =expand_downwards (bprm->vma, pos); +/* We claim to hold the lock - nobody to race with */ + ret =expand_downwards (bprm->vma, pos, true);if (ret <0 )return NULL ; }
@@ -853,7 +854,7 @@ int setup_arg_pages(struct linux_binprm stack_base = vma->vm_end - stack_expand;#endif current->mm->start_stack = bprm->p; - ret =expand_stack (vma, stack_base); + ret =expand_stack_locked (vma, stack_base, true);if (ret) ret = -EFAULT ;
include/linux/mm.h +7 -3
@@ -3192,11 +3192,13 @@ extern vm_fault_t filemap_page_mkwrite(sextern unsigned long stack_guard_gap;/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */ -extern int expand_stack (struct vm_area_struct *vma,unsigned long address); +int expand_stack_locked (struct vm_area_struct *vma,unsigned long address, +bool write_locked); +#define expand_stack (vma,addr) expand_stack_locked(vma,addr,false)/* CONFIG_STACK_GROWSUP still needs to grow downwards at some places */ -extern int expand_downwards (struct vm_area_struct *vma, -unsigned long address); +int expand_downwards (struct vm_area_struct *vma,unsigned long address, +bool write_locked);#if VM_GROWSUP extern int expand_upwards (struct vm_area_struct *vma,unsigned long address);#else
@@ -3297,6 +3299,8 @@ unsigned long change_prot_numa(struct vm#endif struct vm_area_struct *find_extend_vma (struct mm_struct *,unsigned long addr); +struct vm_area_struct *find_extend_vma_locked (struct mm_struct *, +unsigned long addr,bool write_locked);int remap_pfn_range (struct vm_area_struct *,unsigned long addr,unsigned long pfn,unsigned long size,pgprot_t ); int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr,
mm/memory.c +1 -1
@@ -5368,7 +5368,7 @@ struct vm_area_struct *lock_mm_and_find_ goto fail; } -if (expand_stack (vma, addr)) +if (expand_stack_locked (vma, addr, true)) goto fail; success:
mm/mmap.c +33 -17
112 lines not on this page · raw message
mm/nommu.c +2 -1
@@ -643,7 +643,8 @@ struct vm_area_struct *find_extend_vma(s* expand a stack to a given address * - not supported under NOMMU conditions */ -int expand_stack (struct vm_area_struct *vma,unsigned long address) +int expand_stack_locked (struct vm_area_struct *vma,unsigned long address, +bool write_locked) {return -ENOMEM ; }
Greg Kroah-Hartman
maintainerPATCH 20/28 execve: expand new process stack manually ahead of time
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit f313c51d26aa87e69633c9b46efb37a930faca71 upstream.
This is a small step towards a model where GUP itself would not expand the stack, and any user that needs GUP to not look up existing mappings, but actually expand on them, would have to do so manually before-hand, and with the mm lock held for writing.
It turns out that execve() already did almost exactly that, except it didn't take the mm lock at all (it's single-threaded so no locking technically needed, but it could cause lockdep errors). And it only did it for the CONFIG_STACK_GROWSUP case, since in that case GUP has obviously never expanded the stack downwards.
So just make that CONFIG_STACK_GROWSUP case do the right thing with locking, and enable it generally. This will eventually help GUP, and in the meantime avoids a special case and the lockdep issue.
--- fs/exec.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-)
fs/exec.c +21 -16
@@ -200,34 +200,39 @@ static struct page *get_arg_page(struct int write) {struct page *page; +struct vm_area_struct *vma = bprm->vma; +struct mm_struct *mm = bprm->mm;int ret; -unsigned int gup_flags =0 ; -#ifdef CONFIG_STACK_GROWSUP -if (write) { -/* We claim to hold the lock - nobody to race with */ - ret =expand_downwards (bprm->vma, pos, true); -if (ret <0 ) +/* +* Avoid relying on expanding the stack down in GUP (which +* does not work for STACK_GROWSUP anyway), and just do it +* by hand ahead of time. +*/ +if (write && pos < vma->vm_start) { +mmap_write_lock (mm); + ret =expand_downwards (vma, pos, true); +if (unlikely (ret <0 )) { +mmap_write_unlock (mm);return NULL ; - } -#endif - -if (write) - gup_flags |=FOLL_WRITE ; + } +mmap_write_downgrade (mm); + }else +mmap_read_lock (mm);/* * We are doing an exec(). 'current' is the process -* doing the exec and bprm->mm is the new process's mm. +* doing the exec and 'mm' is the new process's mm. */ -mmap_read_lock (bprm->mm); - ret =get_user_pages_remote (bprm->mm, pos,1 , gup_flags, + ret =get_user_pages_remote (mm, pos,1 , + write ?FOLL_WRITE :0 , &page,NULL ,NULL ); -mmap_read_unlock (bprm->mm); +mmap_read_unlock (mm);if (ret <=0 )return NULL ;if (write) -acct_arg_size (bprm,vma_pages (bprm->vma)); +acct_arg_size (bprm,vma_pages (vma));return page; }
Greg Kroah-Hartman
maintainerPATCH 21/28 mm: always expand the stack with the mmap write lock held
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit 8d7071af890768438c14db6172cc8f9f4d04e184 upstream.
This finishes the job of always holding the mmap write lock when extending the user stack vma, and removes the 'write_locked' argument from the vm helper functions again.
For some cases, we just avoid expanding the stack at all: drivers and page pinning really shouldn't be extending any stacks. Let's see if any strange users really wanted that.
It's worth noting that architectures that weren't converted to the new lock_mm_and_find_vma() helper function are left using the legacy "expand_stack()" function, but it has been changed to drop the mmap_lock and take it for writing while expanding the vma. This makes it fairly straightforward to convert the remaining architectures.
As a result of dropping and re-taking the lock, the calling conventions for this function have also changed, since the old vma may no longer be valid. So it will now return the new vma if successful, and NULL - and the lock dropped - if the area could not be extended.
--- arch/ia64/mm/fault.c | 36 ++---------- arch/m68k/mm/fault.c | 9 ++- arch/microblaze/mm/fault.c | 5 + arch/openrisc/mm/fault.c | 5 + arch/parisc/mm/fault.c | 23 +++----- arch/s390/mm/fault.c | 5 + arch/sparc/mm/fault_64.c | 8 +- arch/um/kernel/trap.c | 11 ++- drivers/iommu/amd/iommu_v2.c | 4 - drivers/iommu/iommu-sva.c | 2 fs/binfmt_elf.c | 2 fs/exec.c | 4 - include/linux/mm.h | 16 +---- mm/gup.c | 6 +- mm/memory.c | 10 +++ mm/mmap.c | 121 ++++++++++++++++++++++++++++++++++--------- mm/nommu.c | 18 ++---- 17 files changed, 169 insertions(+), 116 deletions(-)
arch/ia64/mm/fault.c +6 -30
@@ -110,10 +110,12 @@ retry:* register backing store that needs to expand upwards, in * this case vma will be null, but prev_vma will ne non-null */ -if (( !vma && prev_vma ) || (address < vma->vm_start) ) - goto check_expansion; +if (( !vma && prev_vma ) || (address < vma->vm_start) ) { + vma =expand_stack (mm, address); +if (!vma) + goto bad_area_nosemaphore; + } - good_area: code =SEGV_ACCERR ;/* OK, we've got a good vm_area for this memory area. Check the access permissions: */
@@ -177,35 +179,9 @@ retry:mmap_read_unlock (mm);return ; - check_expansion: -if (!(prev_vma && (prev_vma->vm_flags &VM_GROWSUP ) && (address == prev_vma->vm_end))) { -if (!vma) - goto bad_area; -if (!(vma->vm_flags &VM_GROWSDOWN )) - goto bad_area; -if (REGION_NUMBER (address) !=REGION_NUMBER (vma->vm_start) - ||REGION_OFFSET (address) >=RGN_MAP_LIMIT ) - goto bad_area; -if (expand_stack (vma, address)) - goto bad_area; - }else { - vma = prev_vma; -if (REGION_NUMBER (address) !=REGION_NUMBER (vma->vm_start) - ||REGION_OFFSET (address) >=RGN_MAP_LIMIT ) - goto bad_area; -/* -* Since the register backing store is accessed sequentially, -* we disallow growing it by more than a page at a time. -*/ -if (address > vma->vm_end +PAGE_SIZE -sizeof (long )) - goto bad_area; -if (expand_upwards (vma, address)) - goto bad_area; - } - goto good_area; - bad_area:mmap_read_unlock (mm); + bad_area_nosemaphore:if ((isr &IA64_ISR_SP ) || ((isr &IA64_ISR_NA ) && (isr &IA64_ISR_CODE_MASK ) ==IA64_ISR_CODE_LFETCH )) {
arch/m68k/mm/fault.c +6 -3
@@ -105,8 +105,9 @@ retry:if (address +256 <rdusp ()) goto map_err; } -if (expand_stack (vma, address)) - goto map_err; + vma =expand_stack (mm, address); +if (!vma) + goto map_err_nosemaphore;/* * Ok, we have a good vm_area for this memory access, so
@@ -196,10 +197,12 @@ bus_err: goto send_sig; map_err: +mmap_read_unlock (mm); +map_err_nosemaphore: current->thread.signo =SIGSEGV ; current->thread.code =SEGV_MAPERR ; current->thread.faddr = address; - goto send_sig; +return send_fault_sig (regs); acc_err: current->thread.signo =SIGSEGV ;
arch/microblaze/mm/fault.c +3 -2
@@ -192,8 +192,9 @@ retry: && (kernel_mode(regs) || !store_updates_sp(regs))) goto bad_area; } -if (expand_stack (vma, address)) - goto bad_area; + vma =expand_stack (mm, address); +if (!vma) + goto bad_area_nosemaphore; good_area: code =SEGV_ACCERR ;
arch/openrisc/mm/fault.c +3 -2
@@ -127,8 +127,9 @@ retry:if (address +PAGE_SIZE < regs->sp) goto bad_area; } -if (expand_stack (vma, address)) - goto bad_area; + vma =expand_stack (mm, address); +if (!vma) + goto bad_area_nosemaphore;/* * Ok, we have a good vm_area for this memory access, so
arch/parisc/mm/fault.c +11 -12
@@ -288,15 +288,19 @@ void do_page_fault(struct pt_regs *regs, retry:mmap_read_lock (mm); vma =find_vma_prev (mm, address, &prev_vma); -if (!vma || address < vma->vm_start) - goto check_expansion; +if (!vma || address < vma->vm_start) { +if (!prev || !(prev->vm_flags &VM_GROWSUP )) + goto bad_area; + vma =expand_stack (mm, address); +if (!vma) + goto bad_area_nosemaphore; + } +/* * Ok, we have a good vm_area for this memory access. We still need to * check the access permissions. */ -good_area: -if ((vma->vm_flags & acc_type) != acc_type) goto bad_area;
@@ -347,17 +351,13 @@ good_area:mmap_read_unlock (mm);return ; -check_expansion: - vma = prev_vma; -if (vma && (expand_stack (vma, address) ==0 )) - goto good_area; -/* * Something tried to access memory that isn't in our memory map.. */ bad_area:mmap_read_unlock (mm); +bad_area_nosemaphore:if (user_mode (regs)) {int signo, si_code;
@@ -449,7 +449,7 @@ handle_nadtlb_fault(struct pt_regs *regs {unsigned long insn = regs->iir;int breg, treg, xreg, val =0 ; -struct vm_area_struct *vma, *prev_vma; +struct vm_area_struct *vma;struct task_struct *tsk;struct mm_struct *mm;unsigned long address;
@@ -485,7 +485,7 @@ handle_nadtlb_fault(struct pt_regs *regs/* Search for VMA */ address = regs->ior;mmap_read_lock (mm); - vma =find_vma_prev (mm, address, &prev_vma); + vma =vma_lookup (mm, address);mmap_read_unlock (mm);/*
@@ -494,7 +494,6 @@ handle_nadtlb_fault(struct pt_regs *regs*/ acc_type = (insn &0x40 ) ?VM_WRITE :VM_READ ;if (vma - && address >= vma->vm_start && (vma->vm_flags & acc_type) == acc_type) val =1 ; }
arch/s390/mm/fault.c +3 -2
@@ -457,8 +457,9 @@ retry:if (unlikely (vma->vm_start > address)) {if (!(vma->vm_flags &VM_GROWSDOWN )) goto out_up; -if (expand_stack (vma, address)) - goto out_up; + vma =expand_stack (mm, address); +if (!vma) + goto out; }/*
arch/sparc/mm/fault_64.c +5 -3
@@ -383,8 +383,9 @@ continue_fault: goto bad_area; } } -if (expand_stack (vma, address)) - goto bad_area; + vma =expand_stack (mm, address); +if (!vma) + goto bad_area_nosemaphore;/* * Ok, we have a good vm_area for this memory access, so * we can handle it..
@@ -487,8 +488,9 @@ exit_exception:* Fix it, but check if it's kernel or user first.. */ bad_area: - insn =get_fault_insn (regs, insn);mmap_read_unlock (mm); +bad_area_nosemaphore: + insn =get_fault_insn (regs, insn); handle_kernel_fault:do_kernel_fault (regs, si_code, fault_code, insn, address);
arch/um/kernel/trap.c +6 -5
@@ -47,14 +47,15 @@ retry: vma =find_vma (mm, address);if (!vma) goto out; -else if (vma->vm_start <= address) +if (vma->vm_start <= address) goto good_area; -else if (!(vma->vm_flags &VM_GROWSDOWN )) +if (!(vma->vm_flags &VM_GROWSDOWN )) goto out; -else if (is_user && !ARCH_IS_STACKGROW (address)) - goto out; -else if (expand_stack (vma, address)) +if (is_user && !ARCH_IS_STACKGROW (address)) goto out; + vma =expand_stack (mm, address); +if (!vma) + goto out_nosemaphore; good_area: *code_out =SEGV_ACCERR ;
drivers/iommu/amd/iommu_v2.c +2 -2
@@ -485,8 +485,8 @@ static void do_fault(struct work_struct flags |=FAULT_FLAG_REMOTE ;mmap_read_lock (mm); - vma =find_extend_vma (mm, address); -if (!vma || address < vma->vm_start) + vma =vma_lookup (mm, address); +if (!vma)/* failed to get a vma in the right range */ goto out;
drivers/iommu/iommu-sva.c +1 -1
@@ -175,7 +175,7 @@ iommu_sva_handle_iopf(struct iommu_faultmmap_read_lock (mm); - vma =find_extend_vma (mm, prm->addr); + vma =vma_lookup (mm, prm->addr);if (!vma)/* Unmapped area */ goto out_put_mm;
fs/binfmt_elf.c +1 -1
@@ -322,7 +322,7 @@ create_elf_tables(struct linux_binprm *b*/ if (mmap_write_lock_killable (mm))return -EINTR ; - vma =find_extend_vma_locked (mm, bprm->p, true); + vma =find_extend_vma_locked (mm, bprm->p);mmap_write_unlock (mm);if (!vma)return -EFAULT ;
fs/exec.c +2 -2
@@ -211,7 +211,7 @@ static struct page *get_arg_page(struct*/ if (write && pos < vma->vm_start) {mmap_write_lock (mm); - ret =expand_downwards (vma, pos, true); + ret =expand_downwards (vma, pos);if (unlikely (ret <0 )) {mmap_write_unlock (mm);return NULL ;
@@ -859,7 +859,7 @@ int setup_arg_pages(struct linux_binprm stack_base = vma->vm_end - stack_expand;#endif current->mm->start_stack = bprm->p; - ret =expand_stack_locked (vma, stack_base, true); + ret =expand_stack_locked (vma, stack_base);if (ret) ret = -EFAULT ;
include/linux/mm.h +4 -12
@@ -3192,18 +3192,11 @@ extern vm_fault_t filemap_page_mkwrite(sextern unsigned long stack_guard_gap;/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */ -int expand_stack_locked (struct vm_area_struct *vma,unsigned long address, -bool write_locked); -#define expand_stack (vma,addr) expand_stack_locked(vma,addr,false) +int expand_stack_locked (struct vm_area_struct *vma,unsigned long address); +struct vm_area_struct *expand_stack (struct mm_struct * mm,unsigned long addr);/* CONFIG_STACK_GROWSUP still needs to grow downwards at some places */ -int expand_downwards (struct vm_area_struct *vma,unsigned long address, -bool write_locked); -#if VM_GROWSUP -extern int expand_upwards (struct vm_area_struct *vma,unsigned long address); -#else -#define expand_upwards (vma, address) (0) -#endif +int expand_downwards (struct vm_area_struct *vma,unsigned long address);/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ extern struct vm_area_struct *find_vma (struct mm_struct * mm,unsigned long addr);
@@ -3298,9 +3291,8 @@ unsigned long change_prot_numa(struct vm unsigned long start, unsigned long end);#endif -struct vm_area_struct *find_extend_vma (struct mm_struct *,unsigned long addr);struct vm_area_struct *find_extend_vma_locked (struct mm_struct *, -unsigned long addr,bool write_locked); +unsigned long addr);int remap_pfn_range (struct vm_area_struct *,unsigned long addr,unsigned long pfn,unsigned long size,pgprot_t ); int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr,
mm/gup.c +3 -3
@@ -1096,7 +1096,7 @@ static long __get_user_pages(struct mm_s/* first iteration or cross vma bound */ if (!vma || start >= vma->vm_end) { - vma =find_extend_vma (mm, start); + vma =vma_lookup (mm, start);if (!vma &&in_gate_area (mm, start)) { ret = get_gate_page(mm, start & PAGE_MASK, gup_flags, &vma,
@@ -1265,8 +1265,8 @@ int fixup_user_fault(struct mm_struct *m fault_flags |=FAULT_FLAG_ALLOW_RETRY |FAULT_FLAG_KILLABLE ; retry: - vma =find_extend_vma (mm, address); -if (!vma || address < vma->vm_start) + vma =vma_lookup (mm, address); +if (!vma)return -EFAULT ;if (!vma_permits_fault (vma, fault_flags))
mm/memory.c +9 -1
@@ -5368,7 +5368,7 @@ struct vm_area_struct *lock_mm_and_find_ goto fail; } -if (expand_stack_locked (vma, addr, true)) +if (expand_stack_locked (vma, addr)) goto fail; success:
@@ -5713,6 +5713,14 @@ int __access_remote_vm(struct mm_structif (mmap_read_lock_killable (mm))return 0 ; +/* We might need to expand the stack to access it */ + vma =vma_lookup (mm, addr); +if (!vma) { + vma =expand_stack (mm, addr); +if (!vma) +return 0 ; + } +/* ignore errors, just check how much was successfully transferred */ while (len) {int bytes, ret, offset;
mm/mmap.c +97 -24
192 lines not on this page · raw message
mm/nommu.c +7 -11
@@ -631,24 +631,20 @@ struct vm_area_struct *find_vma(struct mEXPORT_SYMBOL (find_vma);/* -* find a VMA -* - we don't extend stack VMAs under NOMMU conditions -*/ -struct vm_area_struct *find_extend_vma (struct mm_struct *mm,unsigned long addr) -{ -return find_vma (mm, addr); -} - -/* * expand a stack to a given address * - not supported under NOMMU conditions */ -int expand_stack_locked (struct vm_area_struct *vma,unsigned long address, -bool write_locked) +int expand_stack_locked (struct vm_area_struct *vma,unsigned long addr) {return -ENOMEM ; } +struct vm_area_struct *expand_stack (struct mm_struct *mm,unsigned long addr) +{ +mmap_read_unlock (mm); +return NULL ; +} +/* * look up the first VMA exactly that exactly matches addr * - should be called with mm->mmap_lock at least held readlocked
Greg Kroah-Hartman
maintainerPATCH 22/28 HID: wacom: Use ktime_t rather than int when dealing with timestamps
In reply to Greg Kroah-HartmanFrom: Jason Gerecke <[email protected]>
commit 9a6c0e28e215535b2938c61ded54603b4e5814c5 upstream.
Code which interacts with timestamps needs to use the ktime_t type returned by functions like ktime_get. The int type does not offer enough space to store these values, and attempting to use it is a recipe for problems. In this particular case, overflows would occur when calculating/storing timestamps leading to incorrect values being reported to userspace. In some cases these bad timestamps cause input handling in userspace to appear hung.
--- drivers/hid/wacom_wac.c | 6 +++--- drivers/hid/wacom_wac.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-)
drivers/hid/wacom_wac.c +3 -3
@@ -1314,7 +1314,7 @@ static void wacom_intuos_pro2_bt_pen(strstruct input_dev *pen_input = wacom->pen_input;unsigned char *data = wacom->data;int number_of_valid_frames =0 ; -int time_interval =15000000 ; +ktime_t time_interval =15000000 ;ktime_t time_packet_received =ktime_get ();int i;
@@ -1348,7 +1348,7 @@ static void wacom_intuos_pro2_bt_pen(strif (number_of_valid_frames) {if (wacom->hid_data.time_delayed) time_interval =ktime_get () - wacom->hid_data.time_delayed; - time_interval /= number_of_valid_frames; + time_interval =div_u64 (time_interval, number_of_valid_frames); wacom->hid_data.time_delayed = time_packet_received; }
@@ -1359,7 +1359,7 @@ static void wacom_intuos_pro2_bt_pen(strbool range = frame[0 ] &0x20 ;bool invert = frame[0 ] &0x10 ;int frames_number_reversed = number_of_valid_frames - i -1 ; -int event_timestamp = time_packet_received - frames_number_reversed * time_interval; +ktime_t event_timestamp = time_packet_received - frames_number_reversed * time_interval;if (!valid)continue ;
drivers/hid/wacom_wac.h +1 -1
@@ -324,7 +324,7 @@ struct hid_data {int ps_connected;bool pad_input_event_flag;unsigned short sequence_number; -int time_delayed; +ktime_t time_delayed; };struct wacom_remote_data {
Greg Kroah-Hartman
maintainerPATCH 23/28 gup: add warning if some caller would seem to want stack expansion
In reply to Greg Kroah-HartmanFrom: Linus Torvalds <[email protected]>
commit a425ac5365f6cb3cc47bf83e6bff0213c10445f7 upstream.
It feels very unlikely that anybody would want to do a GUP in an unmapped area under the stack pointer, but real users sometimes do some really strange things. So add a (temporary) warning for the case where a GUP fails and expanding the stack might have made it work.
It's trivial to do the expansion in the caller as part of getting the mm lock in the first place - see __access_remote_vm() for ptrace, for example - it's just that it's unnecessarily painful to do it deep in the guts of the GUP lookup when we might have to drop and re-take the lock.
I doubt anybody actually does anything quite this strange, but let's be
proactive: adding these warnings is simple, and will make debugging it much easier if they trigger.
--- mm/gup.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
mm/gup.c +10 -2
@@ -1096,7 +1096,11 @@ static long __get_user_pages(struct mm_s/* first iteration or cross vma bound */ if (!vma || start >= vma->vm_end) { - vma =vma_lookup (mm, start); + vma =find_vma (mm, start); +if (vma && (start < vma->vm_start)) { +WARN_ON_ONCE (vma->vm_flags &VM_GROWSDOWN ); + vma =NULL ; + }if (!vma &&in_gate_area (mm, start)) { ret = get_gate_page(mm, start & PAGE_MASK, gup_flags, &vma,
@@ -1265,9 +1269,13 @@ int fixup_user_fault(struct mm_struct *m fault_flags |=FAULT_FLAG_ALLOW_RETRY |FAULT_FLAG_KILLABLE ; retry: - vma =vma_lookup (mm, address); + vma =find_vma (mm, address);if (!vma)return -EFAULT ; +if (address < vma->vm_start ) { +WARN_ON_ONCE (vma->vm_flags &VM_GROWSDOWN ); +return -EFAULT ; + }if (!vma_permits_fault (vma, fault_flags))return -EFAULT ;
Greg Kroah-Hartman
maintainerPATCH 24/28 mm/khugepaged: fix regression in collapse_file()
In reply to Greg Kroah-HartmanFrom: Hugh Dickins <[email protected]>
commit e8c716bc6812202ccf4ce0f0bad3428b794fb39c upstream.
There is no xas_pause(&xas) in collapse_file()'s main loop, at the points where it does xas_unlock_irq(&xas) and then continues.
That would explain why, once two weeks ago and twice yesterday, I have hit the VM_BUG_ON_PAGE(page != xas_load(&xas), page) since "mm/khugepaged:
fix iteration in collapse_file" removed the xas_set(&xas, index) just before it: xas.xa_node could be left pointing to a stale node, if there was concurrent activity on the file which transformed its xarray.
I tried inserting xas_pause()s, but then even bootup crashed on that VM_BUG_ON_PAGE(): there appears to be a subtle "nextness" implicit in xas_pause().
xas_next() and xas_pause() are good for use in simple loops, but not in this one: xas_set() worked well until now, so use xas_set(&xas, index) explicitly at the head of the loop; and change that VM_BUG_ON_PAGE() not to need its own xas_set(), and not to interfere with the xa_state (which would probably stop the crashes from xas_pause(), but I trust that less).
The user-visible effects of this bug (if VM_BUG_ONs are configured out) would be data loss and data leak - potentially - though in practice I expect it is more likely that a subsequent check (e.g. on mapping or on nr_none) would notice an inconsistency, and just abandon the collapse.
--- mm/khugepaged.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
mm/khugepaged.c +3 -4
@@ -1918,9 +1918,9 @@ static int collapse_file(struct mm_struc } }while (1 ); -xas_set (&xas, start);for (index = start; index < end; index++) { - page =xas_next (&xas); +xas_set (&xas, index); + page =xas_load (&xas);VM_BUG_ON (index != xas.xa_index);if (is_shmem) {
@@ -1935,7 +1935,6 @@ static int collapse_file(struct mm_struc result =SCAN_TRUNCATED ; goto xa_locked; } -xas_set (&xas, index +1 ); }if (!shmem_charge (mapping->host,1 )) { result =SCAN_FAIL ;
@@ -2071,7 +2070,7 @@ static int collapse_file(struct mm_strucxas_lock_irq (&xas); -VM_BUG_ON_PAGE (page !=xas_load (&xas), page); +VM_BUG_ON_PAGE (page !=xa_load (xas.xa, index), page);/* * We control three references to the page:
Greg Kroah-Hartman
maintainerPATCH 25/28 fbdev: fix potential OOB read in fast_imageblit()
In reply to Greg Kroah-HartmanFrom: Zhang Shurong <[email protected]>
commit c2d22806aecb24e2de55c30a06e5d6eb297d161d upstream.
There is a potential OOB read at fast_imageblit, for "colortab[(*src >> 4)]" can become a negative value due to "const char *s = image->data, *src".
This change makes sure the index for colortab always positive or zero.
Similar commit:
https://patchwork.kernel.org/patch/11746067
Potential bug report:
https://groups.google.com/g/syzkaller-bugs/c/9ubBXKeKXf4/m/k-QXy4UgAAAJ
--- drivers/video/fbdev/core/sysimgblt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/video/fbdev/core/sysimgblt.c +1 -1
@@ -189,7 +189,7 @@ static void fast_imageblit(const structu32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;u32 ppw =32 /bpp, spitch = (image->width +7 )/8 ;u32 bit_mask, eorx, shift; -const char *s = image->data, *src; +const u8 *s = image->data, *src;u32 *dst;const u32 *tab;size_t tablen;
Greg Kroah-Hartman
maintainerPATCH 26/28 HID: hidraw: fix data race on device refcount
In reply to Greg Kroah-HartmanFrom: Ludvig Michaelsson <[email protected]>
commit 944ee77dc6ec7b0afd8ec70ffc418b238c92f12b upstream.
The hidraw_open() function increments the hidraw device reference counter. The counter has no dedicated synchronization mechanism, resulting in a potential data race when concurrently opening a device.
The race is a regression introduced by commit 8590222e4b02 ("HID:
hidraw: Replace hidraw device table mutex with a rwsem"). While minors_rwsem is intended to protect the hidraw_table itself, by instead acquiring the lock for writing, the reference counter is also protected. This is symmetrical to hidraw_release().
--- drivers/hid/hidraw.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
drivers/hid/hidraw.c +7 -2
@@ -272,7 +272,12 @@ static int hidraw_open(struct inode *ino goto out; } -down_read (&minors_rwsem); +/* +* Technically not writing to the hidraw_table but a write lock is +* required to protect the device refcount. This is symmetrical to +* hidraw_release(). +*/ +down_write (&minors_rwsem);if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { err = -ENODEV ; goto out_unlock;
@@ -301,7 +306,7 @@ static int hidraw_open(struct inode *inospin_unlock_irqrestore (&hidraw_table[minor]->list_lock, flags); file->private_data = list; out_unlock: -up_read (&minors_rwsem); +up_write (&minors_rwsem); out:if (err <0 )kfree (list);
Greg Kroah-Hartman
maintainerPATCH 27/28 HID: logitech-hidpp: add HIDPP_QUIRK_DELAYED_INIT for the T651.
In reply to Greg Kroah-HartmanFrom: Mike Hommey <[email protected]>
commit 5fe251112646d8626818ea90f7af325bab243efa upstream.
commit 498ba2069035 ("HID: logitech-hidpp: Don't restart communication if not necessary") put restarting communication behind that flag, and this was apparently necessary on the T651, but the flag was not set for it.
--- drivers/hid/hid-logitech-hidpp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/hid/hid-logitech-hidpp.c +1 -1
@@ -4553,7 +4553,7 @@ static const struct hid_device_id hidpp_ {/* wireless touchpad T651 */ HID_BLUETOOTH_DEVICE (USB_VENDOR_ID_LOGITECH , USB_DEVICE_ID_LOGITECH_T651), - .driver_data = HIDPP_QUIRK_CLASS_WTP }, + .driver_data = HIDPP_QUIRK_CLASS_WTP | HIDPP_QUIRK_DELAYED_INIT }, { /* Mouse Logitech Anywhere MX */ LDJ_DEVICE(0x1017), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_1P0 }, { /* Mouse logitech M560 */
Greg Kroah-Hartman
maintainerPATCH 28/28 Revert "thermal/drivers/mediatek: Use devm_of_iomap to avoid resource leak in mtk_thermal_probe"
In reply to Greg Kroah-HartmanFrom: Ricardo Cañuelo <[email protected]>
commit 86edac7d3888c715fe3a81bd61f3617ecfe2e1dd upstream.
This reverts commit f05c7b7d9ea9477fcc388476c6f4ade8c66d2d26.
That change was causing a regression in the generic-adc-thermal-probed bootrr test as reported in the kernelci-results list [1].
A proper rework will take longer, so revert it for now.
[1] https://groups.io/g/kernelci-results/message/42660
--- drivers/thermal/mediatek/auxadc_thermal.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-)
drivers/thermal/mediatek/auxadc_thermal.c +2 -12
@@ -1222,12 +1222,7 @@ static int mtk_thermal_probe(struct platreturn -ENODEV ; } - auxadc_base =devm_of_iomap (&pdev->dev, auxadc,0 ,NULL ); -if (IS_ERR (auxadc_base)) { -of_node_put (auxadc); -return PTR_ERR (auxadc_base); - } - + auxadc_base =of_iomap (auxadc,0 ); auxadc_phys_base =of_get_phys_base (auxadc);of_node_put (auxadc);
@@ -1243,12 +1238,7 @@ static int mtk_thermal_probe(struct platreturn -ENODEV ; } - apmixed_base =devm_of_iomap (&pdev->dev, apmixedsys,0 ,NULL ); -if (IS_ERR (apmixed_base)) { -of_node_put (apmixedsys); -return PTR_ERR (apmixed_base); - } - + apmixed_base =of_iomap (apmixedsys,0 ); apmixed_phys_base =of_get_phys_base (apmixedsys);of_node_put (apmixedsys);
Quoted 10 lines · Greg Kroah-Hartman
This is the start of the stable review cycle for the 6.4.1 release. There are 28 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.
Responses should be made by Sat, 01 Jul 2023 18:41:39 +0000. Anything received after that time might be too late.
The whole patch series can be found in one patch at:
Quoted 8 lines
https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.4.1-rc1.gzor in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.gitlinux-6.4.y
and the diffstat can be found below.thanks,
greg k-h
Results from Linaro’s test farm.
Following build regression noticed on Linux stable-rc 6.4 and also noticed on Linux mainline master.
Regressions found on Parisc and Sparc build failed:
- build/gcc-11-defconfig
Parisc Build log:
=============arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags & VM_GROWSUP))
| ^~~~arch/parisc/mm/fault.c:292:22: note: each undeclared identifier is reported only once for each function it appears in
sparc Build log:
===========
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp] arch/sparc/mm/fault_32.c: In function 'force_user_fault':arch/sparc/mm/fault_32.c:315:49: error: 'regs' undeclared (first use in this function)
315 | vma = lock_mm_and_find_vma(mm, address, regs);
| ^~~~arch/sparc/mm/fault_32.c:315:49: note: each undeclared identifier is reported only once for each function it appears in
Links:
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959811/suite/build/test/gcc-11-defconfig/details/
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959811/suite/build/test/gcc-11-defconfig/log
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959890/suite/build/test/gcc-11-defconfig/details/
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959890/suite/build/test/gcc-11-defconfig/log
Both build failures noticed on mainline and sparc build have been
fixed yesterday.
- https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.4-8542-g82a2a5105589/testrun/17963192/suite/build/test/gcc-11-defconfig/history/
Following patch that got fixed
---
From 0b26eadbf200abf6c97c6d870286c73219cdac65 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <[email protected]>
Date: Thu, 29 Jun 2023 20:41:24 -0700
Subject: sparc32: fix lock_mm_and_find_vma() conversion
The sparc32 conversion to lock_mm_and_find_vma() in commit a050ba1e7422 ("mm/fault: convert remaining simple cases to lock_mm_and_find_vma()") missed the fact that we didn't actually have a 'regs' pointer available in the 'force_user_fault()' case.
It's there in the regular page fault path ("do_sparc_fault()"), but not the window underflow/overflow paths.
Which is all fine - we can just pass in a NULL pointer. The register state is only used to avoid deadlock with kernel faults, which is not the case for any of these register window faults.
lock_mm_and_find_vma()")
--
Linaro LKFT
https://lkft.linaro.org
Greg Kroah-Hartman
maintainerQuoted 82 lines · Naresh Kamboju
Quoted 10 lines · Greg Kroah-Hartman
This is the start of the stable review cycle for the 6.4.1 release. There are 28 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.
Responses should be made by Sat, 01 Jul 2023 18:41:39 +0000. Anything received after that time might be too late.
The whole patch series can be found in one patch at:
Quoted 8 lines
https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.4.1-rc1.gzor in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.gitlinux-6.4.y
and the diffstat can be found below.thanks,
greg k-h
Results from Linaro’s test farm.
Following build regression noticed on Linux stable-rc 6.4 and also noticed on Linux mainline master.
Regressions found on Parisc and Sparc build failed:
- build/gcc-11-defconfigParisc Build log:
=============arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))
| ^~~~arch/parisc/mm/fault.c:292:22: note: each undeclared identifier is reported only once for each function it appears insparc Build log:
===========
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp]arch/sparc/mm/fault_32.c: In function 'force_user_fault':arch/sparc/mm/fault_32.c:315:49: error: 'regs' undeclared (first use in this function)
315 | vma =lock_mm_and_find_vma(mm, address, regs);
| ^~~~arch/sparc/mm/fault_32.c:315:49: note: each undeclared identifier is reported only once for each function it appears inLinks:
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959811/suite/build/test/gcc-11-defconfig/details/
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959811/suite/build/test/gcc-11-defconfig/log- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959890/suite/build/test/gcc-11-defconfig/details/
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4-29-g8e5ddb853f08/testrun/17959890/suite/build/test/gcc-11-defconfig/logBoth build failures noticed on mainline and sparc build have been
fixed yesterday.
- https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.4-8542-g82a2a5105589/testrun/17963192/suite/build/test/gcc-11-defconfig/history/Following patch that got fixed
---Quoted 1 line
From
0b26eadbf200abf6c97c6d870286c73219cdac65Mon Sep 17 00:00:00 2001From: Linus Torvalds <[email protected]>
Date: Thu, 29 Jun 2023 20:41:24 -0700
Subject: sparc32: fixlock_mm_and_find_vma()conversionThe sparc32 conversion to
lock_mm_and_find_vma()in commita050ba1e7422("mm/fault: convert remaining simple cases tolock_mm_and_find_vma()") missed the fact that we didn't actually have a 'regs' pointer available in the 'force_user_fault()' case.It's there in the regular page fault path ("
do_sparc_fault()"), but not the window underflow/overflow paths.
Quoted 8 lines
Which is all fine - we can just pass in a NULL pointer. The register state is only used to avoid deadlock with kernel faults, which is not the case for any of these register window faults.
Reported-by Stephen Rothwell <[email protected]>Fixes a050ba1e7422 ("mm/fault: convert remaining simple cases to
lock_mm_and_find_vma()")Signed-off-by Linus Torvalds <[email protected]>
Thanks! That saves me having to dig. I'll go push out updates with this in them...
greg k-h
Quoted 4 lines · Naresh Kamboju
arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))
Bah. "prev" should be "prev_vma" here.
I've pushed out the fix. Greg, apologies. It's
ea3f8272876f parisc: fix expand_stack() conversion
and Naresh already pointed to the similarly silly sparc32 fix.
Linus
Greg Kroah-Hartman
maintainerQuoted 6 lines · Linus Torvalds
Quoted 4 lines · Naresh Kamboju
arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))
Quoted 7 lines
Bah. "prev" should be "
prev_vma" here.I've pushed out the fix. Greg, apologies. It's
ea3f8272876fparisc: fixexpand_stack()conversionand Naresh already pointed to the similarly silly sparc32 fix.
Ah, I saw it hit your repo before your email here, sorry about that. Now picked up.
greg k-h
Quoted 9 lines · Greg Kroah-Hartman
Quoted 8 lines · Linus Torvalds
Quoted 4 lines · Naresh Kamboju
arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))Bah. "prev" should be "
prev_vma" here.
Quoted 8 lines
Quoted 5 lines
I've pushed out the fix. Greg, apologies. It's
ea3f8272876fparisc: fixexpand_stack()conversionand Naresh already pointed to the similarly silly sparc32 fix.
Ah, I saw it hit your repo before your email here, sorry about that. Now picked up.
I've just cherry-picked ea3f8272876f on top of -rc2, built and run-tested it, and everything is OK on parisc.
Thanks!
Helge
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Hi Linus,
Quoted 14 lines · Helge Deller
Quoted 13 lines · Greg Kroah-Hartman
Quoted 12 lines · Linus Torvalds
Quoted 4 lines · Naresh Kamboju
arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function) 292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))Bah. "prev" should be "
prev_vma" here.I've pushed out the fix. Greg, apologies. It's
ea3f8272876fparisc: fixexpand_stack()conversion
Quoted 7 lines
Quoted 4 lines
Quoted 1 line
and Naresh already pointed to the similarly silly sparc32 fix.
Ah, I saw it hit your repo before your email here, sorry about that. Now picked up.
I've just cherry-picked
ea3f8272876fon top of -rc2, built and run-tested it, and everything is OK on parisc.
Actually, your changes seems to trigger...:
root@debian:~# /usr/bin/ls /usr/bin/* -bash: /usr/bin/ls: Argument list too long
or with a long gcc argument list:
gcc: fatal error: cannot execute '/usr/lib/gcc/hppa-linux-gnu/12/cc1': execv: Argument list too long
I'm trying to understand what's missing, but maybe you have some idea?
Helge
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 5 lines · Helge Deller
Actually, your changes seems to trigger...:
root@debian:~# /usr/bin/ls /usr/bin/* -bash: /usr/bin/ls: Argument list too long
So this only happens with _fairly_ long argument lists, right? Maybe your config has a 64kB page size, and normal programs never expand beyond a single page?
I bet it is because of f313c51d26aa ("execve: expand new process stack manually ahead of time"), but I don't see exactly why.
But pa-risc is the only architecture with CONFIG_STACK_GROWSUP, and while I really thought that commit should do the exact same thing as the old
#ifdef CONFIG_STACK_GROWSUP
special case, I must clearly have been wrong.
Would you mind just verifying that yes, that commit on mainline is broken for you, and the previous one works?
Linus
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 3 lines · Linus Torvalds
Would you mind just verifying that yes, that commit on mainline is broken for you, and the previous one works?
Also, while I looked at it again, and still didn't understand why parisc would be different here, I *did* realize that because parisc has a stack that grows up, the debug warning I added for GUP won't trigger.
So if I got that execve() logic wrong for STACK_GROWSUP (which I clearly must have), then exactly because it's grows-up, a GUP failure wouldn't warn about not expanding the stack.
IOW, would you mind applying something like this on top of the current kernel, and let me know if it warns?
.. and here I thought ia64 would be the pain-point. Silly me.
Linus
mm/gup.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
mm/gup.c +5 -1
@@ -1168,11 +1168,15 @@ static long __get_user_pages(struct mm_struct *mm,/* first iteration or cross vma bound */ if (!vma || start >= vma->vm_end) { - vma =find_vma (mm, start); +struct vm_area_struct *prev =NULL ; + vma =find_vma_prev (mm, start, &prev);if (vma && (start < vma->vm_start)) {WARN_ON_ONCE (vma->vm_flags &VM_GROWSDOWN ); vma =NULL ; } +if (!vma && prev && start >= prev->vm_end) +WARN_ON_ONCE (prev->vm_flags &VM_GROWSUP ); +if (!vma &&in_gate_area (mm, start)) { ret = get_gate_page(mm, start & PAGE_MASK, gup_flags, &vma,
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 11 lines · Linus Torvalds
Quoted 3 lines · Linus Torvalds
Would you mind just verifying that yes, that commit on mainline is broken for you, and the previous one works?
Also, while I looked at it again, and still didn't understand why parisc would be different here, I *did* realize that because parisc has a stack that grows up, the debug warning I added for GUP won't trigger.
Quoted 7 lines
So if I got that
execve()logic wrong forSTACK_GROWSUP(which I clearly must have), then exactly because it's grows-up, a GUP failure wouldn't warn about not expanding the stack.IOW, would you mind applying something like this on top of the current kernel, and let me know if it warns?
I can reproduce the problem in qemu. However, I do not see a warning after applying your patch.
Guenter
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 3 lines · Guenter Roeck
I can reproduce the problem in qemu. However, I do not see a warning after applying your patch.
Funky, funky.
I'm assuming it's the
page = get_arg_page(bprm, pos, 1);
if (!page) {
ret = -E2BIG;
goto out;
}in copy_strings() that causes this. Or possibly, the version in copy_string_kernel().
Does *this* get that "pr_warn()" printout (and a stack trace once, just for good measure)?
Linus
mm/gup.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
mm/gup.c +5 -1
@@ -1168,11 +1168,15 @@ static long __get_user_pages(struct mm_struct *mm,/* first iteration or cross vma bound */ if (!vma || start >= vma->vm_end) { - vma =find_vma (mm, start); +struct vm_area_struct *prev =NULL ; + vma =find_vma_prev (mm, start, &prev);if (vma && (start < vma->vm_start)) {WARN_ON_ONCE (vma->vm_flags &VM_GROWSDOWN ); vma =NULL ; } +if (!vma && prev && start >= prev->vm_end) +WARN_ON_ONCE (prev->vm_flags &VM_GROWSUP ); +if (!vma &&in_gate_area (mm, start)) { ret = get_gate_page(mm, start & PAGE_MASK, gup_flags, &vma,
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 15 lines · Linus Torvalds
Quoted 3 lines · Guenter Roeck
I can reproduce the problem in qemu. However, I do not see a warning after applying your patch.
Funky, funky.
I'm assuming it's the
page = get_arg_page(bprm, pos, 1); if (!page) { ret = -E2BIG; goto out; }
Quoted 6 lines
in
copy_strings()that causes this. Or possibly, the version incopy_string_kernel().Does *this* get that "
pr_warn()" printout (and a stack trace once, just for good measure)?
Sorry, you lost me. Isn't that the same patch as before ? Or is it just time for me to go to bed ?
Guenter
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 3 lines · Guenter Roeck
Sorry, you lost me. Isn't that the same patch as before ? Or is it just time for me to go to bed ?
No, I think it's time for *me* to go to bed.
Let's get the right diff this time.
Linus
fs/exec.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
fs/exec.c +8 -1
@@ -212,6 +212,9 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, ret =expand_downwards (vma, pos);if (unlikely (ret <0 )) {mmap_write_unlock (mm); +pr_warn ("stack expand failed: %lx-%lx (%lx)\n" , + vma->vm_start, vma->vm_end, pos); +WARN_ON_ONCE (1 );return NULL ; }mmap_write_downgrade (mm);
@@ -226,8 +229,12 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, write ?FOLL_WRITE :0 , &page, NULL);mmap_read_unlock (mm); -if (ret <=0 ) +if (ret <=0 ) { +pr_warn ("get_user_pages_remote failed: %lx-%lx (%lx)\n" , + vma->vm_start, vma->vm_end, pos); +WARN_ON_ONCE (1 );return NULL ; + }if (write)acct_arg_size (bprm,vma_pages (vma));
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 9 lines · Linus Torvalds
Quoted 3 lines · Guenter Roeck
Sorry, you lost me. Isn't that the same patch as before ? Or is it just time for me to go to bed ?
No, I think it's time for *me* to go to bed.
Let's get the right diff this time.
Here you are:
[ 31.188688] stack expand failed: ffeff000-fff00000 (ffefeff2) [ 31.189131] ------------[ cut here ]------------ [ 31.189259] WARNING: CPU: 0 PID: 472 at fs/exec.c:217 get_arg_page+0x1e8/0x1f4 [ 31.189827] Modules linked in: [ 31.190083] CPU: 0 PID: 472 Comm: sh Tainted: G N 6.4.0-32bit+ #1 [ 31.190213] Hardware name: 9000/778/B160L [ 31.190347] [ 31.190407] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI [ 31.190496] PSW: 00000000000001001011111100001111 Tainted: G N [ 31.190625] r00-03 0004bf0f 11026240 1034a3ec 12bb41c0 [ 31.190741] r04-07 127ec400 00000001 12b725a4 12b72530 [ 31.190821] r08-11 129e6708 ffefeff2 2ff9d000 ffeff000 [ 31.190895] r12-15 127ec400 10e463f0 10e34348 12a4d1a0 [ 31.190962] r16-19 00000002 00001000 ffefe000 12a4d1a0 [ 31.191033] r20-23 0000000f 00001a46 013ae000 12bb4498 [ 31.191103] r24-27 11542330 00000000 115430a0 10ed98d8 [ 31.191173] r28-31 00000031 00000310 12bb4240 0000000f [ 31.191251] sr00-03 00000000 00000000 00000000 000000a0 [ 31.191332] sr04-07 00000000 00000000 00000000 00000000 [ 31.191407] [ 31.191443] IASQ: 00000000 00000000 IAOQ: 1034a3ec 1034a3f0 [ 31.191522] IIR: 03ffe01f ISR: 00000000 IOR: 1065d424 [ 31.191593] CPU: 0 CR30: 12a4d1a0 CR31: 00000000 [ 31.192675] ORIG_R28: 12a4d1a0 [ 31.192770] IAOQ[0]: get_arg_page+0x1e8/0x1f4 [ 31.192851] IAOQ[1]: get_arg_page+0x1ec/0x1f4 [ 31.192922] RP(r2): get_arg_page+0x1e8/0x1f4 [ 31.193007] Backtrace: [ 31.193085] [<1034a9cc>] copy_strings+0x148/0x3d8 [ 31.193214] [<1034ad94>] do_execveat_common+0x138/0x21c [ 31.193302] [<1034bcc4>] sys_execve+0x3c/0x54 [ 31.193400] [<101af1b4>] syscall_exit+0x0/0x10 [ 31.193562] [ 31.193698] ---[ end trace 0000000000000000 ]--- [ 31.200551] stack expand failed: ffeff000-fff00000 (ffefefee)
/bin/sh: ls: Argument list too long
Guenter
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 4 lines · Guenter Roeck
Here you are:
[ 31.188688] stack expand failed: ffeff000-fff00000 (ffefeff2)
Ahhah!
I think the problem is actually ridiculously simple.
The thing is, the parisc stack expands upwards. That's obvious. I've mentioned it several times in just this thread as being the thing that makes parisc special.
But it's *so* obvious that I didn't even think about what it really implies.
And part of all the changes was this part in expand_downwards():
if (!(vma->vm_flags & VM_GROWSDOWN))
return -EFAULT;and that will *always* fail on parisc, because - as said multiple times - the parisc stack expands upwards. It doesn't have VM_GROWSDOWN set.
What a dum-dum I am.
And I did it that way because the *normal* stack expansion obviously wants it that way and putting the check there not only made sense, but simplified other code.
But fs/execve.c is special - and only special for parisc - in that it really wants to expand a normally upwards-growing stack downwards unconditionally.
Anyway, I think that new check in expand_downwards() is the right thing to do, and the real fix here is to simply make vm_flags reflect reality.
Because during execve, that stack that will _eventually_ grow upwards, does in fact grow downwards. Let's make it reflect that.
We already do magical extra setup for the stack flags during setup (VM_STACK_INCOMPLETE_SETUP), so extending that logic to contain VM_GROWSDOWN seems sane and the right thing to do.
IOW, I think a patch like the attached will fix the problem for real.
It needs a good commit log and maybe a code comment or two, but before I bother to do that, let's verify that yes, it does actually fix things.
In the meantime, I will actually go to bed, but I'm pretty sure this is it.
Linus
include/linux/mm.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
include/linux/mm.h +3 -1
@@ -377,7 +377,7 @@ extern unsigned int kobjsize(const void *objp);#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ /* Bits set in the VMA until the stack is in its final location */ -#define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ) +#define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY)#define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
@@ -399,8 +399,10 @@ extern unsigned int kobjsize(const void *objp);#ifdef CONFIG_STACK_GROWSUP #define VM_STACK VM_GROWSUP +#define VM_STACK_EARLY VM_GROWSDOWN#else #define VM_STACK VM_GROWSDOWN +#define VM_STACK_EARLY 0#endif #define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Hi Linus,
Quoted 46 lines · Linus Torvalds
Quoted 4 lines · Guenter Roeck
Here you are:
[ 31.188688] stack expand failed: ffeff000-fff00000 (ffefeff2)Ahhah!
I think the problem is actually ridiculously simple.
The thing is, the parisc stack expands upwards. That's obvious. I've mentioned it several times in just this thread as being the thing that makes parisc special.
But it's *so* obvious that I didn't even think about what it really implies.
And part of all the changes was this part in
expand_downwards():if (!(vma->vm_flags & VM_GROWSDOWN)) return -EFAULT;and that will *always* fail on parisc, because - as said multiple times - the parisc stack expands upwards. It doesn't have
VM_GROWSDOWNset.What a dum-dum I am.
And I did it that way because the *normal* stack expansion obviously wants it that way and putting the check there not only made sense, but simplified other code.
But
fs/execve.cis special - and only special for parisc - in that it really wants to expand a normally upwards-growing stack downwards unconditionally.Anyway, I think that new check in
expand_downwards()is the right thing to do, and the real fix here is to simply makevm_flagsreflect reality.Because during execve, that stack that will _eventually_ grow upwards, does in fact grow downwards. Let's make it reflect that.
We already do magical extra setup for the stack flags during setup (
VM_STACK_INCOMPLETE_SETUP), so extending that logic to containVM_GROWSDOWNseems sane and the right thing to do.
Quoted 7 lines
IOW, I think a patch like the attached will fix the problem for real.
It needs a good commit log and maybe a code comment or two, but before I bother to do that, let's verify that yes, it does actually fix things.
In the meantime, I will actually go to bed, but I'm pretty sure this is it.
Great, that patch fixes it!
I wonder if you want to
#define VM_STACK_EARLY VM_GROWSDOWN
even for the case where the stack grows down too (instead of 0), just to make clear that in both cases the stack goes downwards initially.
Helge
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 2 lines · Helge Deller
Great, that patch fixes it!
Yeah, I was pretty sure this was it, but it's good to have it confirmed. Committed.
Quoted 4 lines
I wonder if you want to
#defineVM_STACK_EARLYVM_GROWSDOWN
even for the case where the stack grows down too (instead of 0), just to make clear that in both cases the stack goes downwards initially.
No, that wouldn't work for the simple reason that the special bits in VM_STACK_INCOMPLETE_SETUP are always cleared after the stack setup is done.
So if we added VM_GROWSDOWN to those early bits in general, the bit would then be cleared even when that wasn't the intent.
Yes, yes, we could change the VM_STACK_INCOMPLETE_SETUP logic to only clear some of the bits in the end, but the end result would be practically the same: we'd still have to do different things for grows-up vs grows-down cases, so the difference might as well be here in the VM_STACK_EARLY bit.
Linus
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 7 lines · Linus Torvalds
Quoted 2 lines · Helge Deller
Great, that patch fixes it!
Yeah, I was pretty sure this was it, but it's good to have it confirmed. Committed.
FWIW, my qemu boot tests didn't find any problems with other architectures.
Guenter
Quoted 19 lines
Quoted 4 lines
I wonder if you want to
#defineVM_STACK_EARLYVM_GROWSDOWN
even for the case where the stack grows down too (instead of 0), just to make clear that in both cases the stack goes downwards initially.No, that wouldn't work for the simple reason that the special bits in
VM_STACK_INCOMPLETE_SETUPare always cleared after the stack setup is done.So if we added
VM_GROWSDOWNto those early bits in general, the bit would then be cleared even when that wasn't the intent.Yes, yes, we could change the
VM_STACK_INCOMPLETE_SETUPlogic to only clear some of the bits in the end, but the end result would be practically the same: we'd still have to do different things for grows-up vs grows-down cases, so the difference might as well be here in theVM_STACK_EARLYbit.Linus
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 2 lines · Guenter Roeck
FWIW, my qemu boot tests didn't find any problems with other architectures.
Thanks. This whole "let's get the stack expansion locking right" wasn't exactly buttery smooth, but given all our crazy architectures it was not entirely unexpected.
Let's hope it really is all done now,
Linus
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
In reply to Linus TorvaldsQuoted 6 lines · Linus Torvalds
Quoted 2 lines · Helge Deller
Great, that patch fixes it!
Yeah, I was pretty sure this was it, but it's good to have it confirmed. Committed.
Thank you!
Nice to see that Greg picked up the patch for stable that fast as well!
Quoted 9 lines
Quoted 4 lines
I wonder if you want to
#defineVM_STACK_EARLYVM_GROWSDOWN
even for the case where the stack grows down too (instead of 0), just to make clear that in both cases the stack goes downwards initially.No, that wouldn't work for the simple reason that the special bits in
VM_STACK_INCOMPLETE_SETUPare always cleared after the stack setup is done.
Quoted 8 lines
So if we added
VM_GROWSDOWNto those early bits in general, the bit would then be cleared even when that wasn't the intent.Yes, yes, we could change the
VM_STACK_INCOMPLETE_SETUPlogic to only clear some of the bits in the end, but the end result would be practically the same: we'd still have to do different things for grows-up vs grows-down cases, so the difference might as well be here in theVM_STACK_EARLYbit.
Ok, thanks for explainig!
Helge
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 11 lines · Helge Deller
Quoted 6 lines · Linus Torvalds
Quoted 2 lines · Helge Deller
Great, that patch fixes it!
Yeah, I was pretty sure this was it, but it's good to have it confirmed. Committed.
Thank you!
Nice to see that Greg picked up the patch for stable that fast as well!
Sorry, where? I was just about to check if it was marked for backporting but I can't see it in Greg's trees yet.
We need it fo 6.1, 6.3, 6.4.
(Apologies if I'm missing it somewhere obvious.)
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 12 lines · Sam James
Quoted 10 lines · Helge Deller
Quoted 6 lines · Linus Torvalds
Quoted 2 lines · Helge Deller
Great, that patch fixes it!
Yeah, I was pretty sure this was it, but it's good to have it confirmed. Committed.
Thank you!
Quoted 8 lines
Quoted 1 line
Nice to see that Greg picked up the patch for stable that fast as well!
Sorry, where? I was just about to check if it was marked for backporting but I can't see it in Greg's trees yet.
We need it fo 6.1, 6.3, 6.4.
(Apologies if I'm missing it somewhere obvious.)
.. and I was. I see it now, sorry!
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
In reply to Linus TorvaldsQuoted 46 lines · Linus Torvalds
Quoted 4 lines · Guenter Roeck
Here you are:
[ 31.188688] stack expand failed: ffeff000-fff00000 (ffefeff2)Ahhah!
I think the problem is actually ridiculously simple.
The thing is, the parisc stack expands upwards. That's obvious. I've mentioned it several times in just this thread as being the thing that makes parisc special.
But it's *so* obvious that I didn't even think about what it really implies.
And part of all the changes was this part in
expand_downwards():if (!(vma->vm_flags & VM_GROWSDOWN)) return -EFAULT;and that will *always* fail on parisc, because - as said multiple times - the parisc stack expands upwards. It doesn't have
VM_GROWSDOWNset.What a dum-dum I am.
And I did it that way because the *normal* stack expansion obviously wants it that way and putting the check there not only made sense, but simplified other code.
But
fs/execve.cis special - and only special for parisc - in that it really wants to expand a normally upwards-growing stack downwards unconditionally.Anyway, I think that new check in
expand_downwards()is the right thing to do, and the real fix here is to simply makevm_flagsreflect reality.Because during execve, that stack that will _eventually_ grow upwards, does in fact grow downwards. Let's make it reflect that.
We already do magical extra setup for the stack flags during setup (
VM_STACK_INCOMPLETE_SETUP), so extending that logic to containVM_GROWSDOWNseems sane and the right thing to do.
Quoted 6 lines
IOW, I think a patch like the attached will fix the problem for real.
It needs a good commit log and maybe a code comment or two, but before I bother to do that, let's verify that yes, it does actually fix things.
Yes, it does. I'll run a complete qemu test with it applied to be sure there is no impact on other architectures (yes, I know, that should not be the case, but better safe than sorry). I'll even apply
https://lore.kernel.org/all/[email protected]/raw
to be able to test sh4.
Guenter
Re: [PATCH 6.4 00/28] 6.4.1-rc1 review - hppa argument list too long
Quoted 54 lines · Guenter Roeck
Quoted 46 lines · Linus Torvalds
Quoted 4 lines · Guenter Roeck
Here you are:
[ 31.188688] stack expand failed: ffeff000-fff00000 (
ffefeff2)Ahhah!
I think the problem is actually ridiculously simple.
The thing is, the parisc stack expands upwards. That's obvious. I've mentioned it several times in just this thread as being the thing that makes parisc special.
But it's *so* obvious that I didn't even think about what it really implies.
And part of all the changes was this part in
expand_downwards():if (!(vma->vm_flags &
VM_GROWSDOWN))
return-EFAULT;and that will *always* fail on parisc, because - as said multiple times - the parisc stack expands upwards. It doesn't have
VM_GROWSDOWNset.What a dum-dum I am.
And I did it that way because the *normal* stack expansion obviously wants it that way and putting the check there not only made sense, but simplified other code.
But
fs/execve.cis special - and only special for parisc - in that it really wants to expand a normally upwards-growing stack downwards unconditionally.Anyway, I think that new check in
expand_downwards()is the right thing to do, and the real fix here is to simply makevm_flagsreflect reality.Because during execve, that stack that will _eventually_ grow upwards, does in fact grow downwards. Let's make it reflect that.
We already do magical extra setup for the stack flags during setup (
VM_STACK_INCOMPLETE_SETUP), so extending that logic to containVM_GROWSDOWNseems sane and the right thing to do.Quoted 6 lines
IOW, I think a patch like the attached will fix the problem for real.
It needs a good commit log and maybe a code comment or two, but before I bother to do that, let's verify that yes, it does actually fix things.
Quoted 6 lines
Yes, it does. I'll run a complete qemu test with it applied to be sure there is no impact on other architectures (yes, I know, that should not be the case, but better safe than sorry). I'll even apply
https://lore.kernel.org/all/[email protected]/raw
to be able to test sh4.
Meh, should have figured. That fixes one problem with sh4 builds and creates another. Should have figured.
Guenter
Quoted 8 lines · Linus Torvalds
Quoted 4 lines · Naresh Kamboju
arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))Bah. "prev" should be "
prev_vma" here.
Quoted 7 lines
I've pushed out the fix. Greg, apologies. It's
ea3f8272876fparisc: fixexpand_stack()conversionand Naresh already pointed to the similarly silly sparc32 fix.
Linus
Did you see that one (in mainline) ?
Building csky:defconfig ... failed
--------------
Error log:arch/csky/mm/fault.c: In function 'do_page_fault':arch/csky/mm/fault.c:240:40: error: 'address' undeclared (first use in this function); did you mean 'addr'?
240 | vma = lock_mm_and_find_vma(mm, address, regs);
Guenter
Quoted 17 lines · Guenter Roeck
Quoted 8 lines · Linus Torvalds
Quoted 4 lines · Naresh Kamboju
arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function) 292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))Bah. "prev" should be "
prev_vma" here.Quoted 7 lines
I've pushed out the fix. Greg, apologies. It's
ea3f8272876fparisc: fixexpand_stack()conversionand Naresh already pointed to the similarly silly sparc32 fix.
Linus
Quoted 9 lines
Did you see that one (in mainline) ?
Building csky:defconfig ... failed
--------------
Error log:arch/csky/mm/fault.c: In function 'do_page_fault':arch/csky/mm/fault.c:240:40: error: 'address' undeclared (first use in this function); did you mean 'addr'?
240 | vma =lock_mm_and_find_vma(mm, address, regs);
This is also in {6.1,6.3,6.4}-rc unless I am missing something.
Guenter
Quoted 4 lines · Guenter Roeck
Did you see that one (in mainline) ?
Building csky:defconfig ... failed
Nope. Thanks. Obvious fix: 'address' is called 'addr' here.
I knew we had all these tiny little mazes that looked the same but were just _subtly_ different, but I still ended up doing too much cut-and-paste.
And I only ended up cross-compiling the fairly small set that I had existing cross-build environments for. Which was less than half our ~24 different architectures.
Oh well. We'll get them all. Eventually. Let me go fix up that csky case.
Linus
Quoted 2 lines · Linus Torvalds
Oh well. We'll get them all. Eventually. Let me go fix up that csky case.
It's commit e55e5df193d2 ("csky: fix up lock_mm_and_find_vma() conversion").
Let's hope all the problems are these kinds of silly - but obvious - naming differences between different architectures.
Because as long as they cause build errors, they may be embarrassing, but easy to find and notice.
I may not have cared enough about some of these architectures, and it shows. sparc32. parisc. csky...
Linus
Quoted 7 lines · Linus Torvalds
Quoted 2 lines · Linus Torvalds
Oh well. We'll get them all. Eventually. Let me go fix up that csky case.
It's commit
e55e5df193d2("csky: fix uplock_mm_and_find_vma()conversion").
Quoted 9 lines
Let's hope all the problems are these kinds of silly - but obvious - naming differences between different architectures.
Because as long as they cause build errors, they may be embarrassing, but easy to find and notice.
I may not have cared enough about some of these architectures, and it shows. sparc32. parisc. csky...
There is one more, unfortunately.
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... failed
------------
Error log:arch/xtensa/mm/fault.c: In function ‘do_page_fault’:arch/xtensa/mm/fault.c:133:8: error: implicit declaration of function ‘lock_mm_and_find_vma’
This affects all stable release candidates as well as mainline. mmu builds are fine, and indeed lock_mm_and_find_vma() is only declared for CONFIG_MMU. I don't know if this needs a dummy or some other fix for the nommu case.
Guenter
Quoted 4 lines · Guenter Roeck
There is one more, unfortunately.
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... failed
Heh. I didn't even realize that anybody would ever do lock_mm_and_find_vma() code on a nommu platform.
With nommu, handle_mm_fault() will just BUG(), so it's kind of pointless to do any of this at all, and I didn't expect anybody to have this page faulting path that just causes that BUG() for any faults.
But it turns out xtensa has a notion of protection faults even for NOMMU configs:
config PFAULT
bool "Handle protection faults" if EXPERT && !MMU default y
help
Handle protection faults. MMU configurations must enable it. noMMU configurations may disable it if used memory map never generates protection faults or faults are always fatal.
If unsure, say Y.
which is why it violated my expectations so badly.
I'm not sure if that protection fault handling really ever gets quite this far (it certainly should *not* make it to the BUG() in handle_mm_fault()), but I think the attached patch is likely the right thing to do.
Can you check if it fixes that xtensa case? It looks ObviouslyCorrect(tm) to me, but considering that I clearly missed this case existing AT ALL, it might be best to double-check.
Linus
include/linux/mm.h | 5 +++-- mm/nommu.c | 11 +++++++++++ 2 files changed, 14 insertions(+), 2 deletions(-)
include/linux/mm.h +3 -2
@@ -2323,6 +2323,9 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);void truncate_pagecache_range (struct inode *inode,loff_t offset,loff_t end);int generic_error_remove_page (struct address_space *mapping,struct page *page); +struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, +unsigned long address,struct pt_regs *regs); +#ifdef CONFIG_MMU extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, unsigned int flags,
@@ -2334,8 +2337,6 @@ void unmap_mapping_pages(struct address_space *mapping, pgoff_t start, pgoff_t nr, bool even_cows);void unmap_mapping_range (struct address_space *mapping,loff_t const holebegin,loff_t const holelen,int even_cows); -struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, -unsigned long address,struct pt_regs *regs);#else static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, unsigned int flags,
mm/nommu.c +11 -0
@@ -630,6 +630,17 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) }EXPORT_SYMBOL (find_vma); +/* +* At least xtensa ends up having protection faults even with no +* MMU.. No stack expansion, at least. +*/ +struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, +unsigned long addr,struct pt_regs *regs) +{ +mmap_read_lock (mm); +return vma_lookup (mm, addr); +} +/* * expand a stack to a given address * - not supported under NOMMU conditions
Quoted 34 lines · Linus Torvalds
Quoted 4 lines · Guenter Roeck
There is one more, unfortunately.
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... failed
Heh. I didn't even realize that anybody would ever do
lock_mm_and_find_vma()code on a nommu platform.With nommu,
handle_mm_fault()will justBUG(), so it's kind of pointless to do any of this at all, and I didn't expect anybody to have this page faulting path that just causes thatBUG()for any faults.But it turns out xtensa has a notion of protection faults even for NOMMU configs:
config PFAULT
bool "Handle protection faults" if EXPERT && !MMU default y
help
Handle protection faults. MMU configurations must enable it. noMMU configurations may disable it if used memory map never generates protection faults or faults are always fatal.If unsure, say Y.
which is why it violated my expectations so badly.
I'm not sure if that protection fault handling really ever gets quite this far (it certainly should *not* make it to the
BUG()inhandle_mm_fault()), but I think the attached patch is likely the right thing to do.
Quoted 5 lines
Can you check if it fixes that xtensa case? It looks ObviouslyCorrect(tm) to me, but considering that I clearly missed this case existing AT ALL, it might be best to double-check.
Linus
Yes, the patch below fixes the problem.
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... running ......... passed
Thanks,
Guenter
Quoted 49 lines
include/linux/mm.h | 5 +++-- mm/nommu.c | 11 +++++++++++ 2 files changed, 14 insertions(+), 2 deletions(-)include/linux/mm.h +3
-2@@ -2323,6 +2323,9 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);void truncate_pagecache_range (struct inode *inode,loff_t offset,loff_t end);int generic_error_remove_page (struct address_space *mapping,struct page *page); +struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, +unsigned long address,struct pt_regs *regs); +#ifdef CONFIG_MMU extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, unsigned int flags,@@ -2334,8 +2337,6 @@ void unmap_mapping_pages(struct address_space *mapping, pgoff_t start, pgoff_t nr, bool even_cows);void unmap_mapping_range (struct address_space *mapping,loff_t const holebegin,loff_t const holelen,int even_cows); -struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, -unsigned long address,struct pt_regs *regs);#else static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, unsigned int flags,mm/nommu.c +11
-0@@ -630,6 +630,17 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) }EXPORT_SYMBOL (find_vma); +/* +* At least xtensa ends up having protection faults even with no +* MMU.. No stack expansion, at least. +*/ +struct vm_area_struct *lock_mm_and_find_vma (struct mm_struct *mm, +unsigned long addr,struct pt_regs *regs) +{ +mmap_read_lock (mm); +return vma_lookup (mm, addr); +} +/* * expand a stack to a given address * - not supported under NOMMU conditions
Quoted 4 lines · Guenter Roeck
Yes, the patch below fixes the problem.
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... running ......... passed
Thanks. Committed as
d85a143b69ab ("xtensa: fix NOMMU build with lock_mm_and_find_vma()
conversion")
and pushed out.
Linus
Greg Kroah-Hartman
maintainerQuoted 4 lines · Linus Torvalds
Quoted 3 lines · Guenter Roeck
Yes, the patch below fixes the problem.
Quoted 8 lines
Quoted 1 line
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... running ......... passed
Thanks. Committed as
d85a143b69ab("xtensa: fix NOMMU build withlock_mm_and_find_vma()
conversion")and pushed out.
Thanks, now queued up.
greg k-h
Hi Linus,
Quoted 5 lines · Linus Torvalds
Quoted 3 lines · Guenter Roeck
Yes, the patch below fixes the problem.
Quoted 8 lines
Quoted 1 line
Building xtensa:de212:kc705-nommu:nommu_kc705_defconfig ... running ......... passed
Thanks. Committed as
d85a143b69ab("xtensa: fix NOMMU build withlock_mm_and_find_vma()
conversion")and pushed out.
Thanks for the build fix. Unfortunately despite being obviously correct it doesn't release the mm lock in case VMA is not found, so it results in a runtime hang. I've posted a fix for that.
Signature · 2 lines
Thanks. -- Max
Quoted 4 lines · Max Filippov
Thanks for the build fix. Unfortunately despite being obviously correct it doesn't release the mm lock in case VMA is not found, so it results in a runtime hang. I've posted a fix for that.
Heh. I woke up this morning to that feeling of "Duh!" about this, and find you already had fixed it. Patch applied.
Linus
Greg Kroah-Hartman
maintainerQuoted 12 lines · Linus Torvalds
Quoted 4 lines · Guenter Roeck
Did you see that one (in mainline) ?
Building csky:defconfig ... failed
Nope. Thanks. Obvious fix: 'address' is called 'addr' here.
I knew we had all these tiny little mazes that looked the same but were just _subtly_ different, but I still ended up doing too much cut-and-paste.
Quoted 5 lines
And I only ended up cross-compiling the fairly small set that I had existing cross-build environments for. Which was less than half our ~24 different architectures.
Oh well. We'll get them all. Eventually. Let me go fix up that csky case.
Thanks, I've picked that up now as well.
greg k-h
Greg Kroah-Hartman
maintainerQuoted 31 lines · Naresh Kamboju
Quoted 10 lines · Greg Kroah-Hartman
This is the start of the stable review cycle for the 6.4.1 release. There are 28 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.
Responses should be made by Sat, 01 Jul 2023 18:41:39 +0000. Anything received after that time might be too late.
The whole patch series can be found in one patch at:
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https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.4.1-rc1.gzor in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.gitlinux-6.4.y
and the diffstat can be found below.thanks,
greg k-h
Results from Linaro’s test farm.
Following build regression noticed on Linux stable-rc 6.4 and also noticed on Linux mainline master.
Regressions found on Parisc and Sparc build failed:
- build/gcc-11-defconfig
Quoted 9 lines
Parisc Build log:
=============arch/parisc/mm/fault.c: In function 'do_page_fault':arch/parisc/mm/fault.c:292:22: error: 'prev' undeclared (first use in this function)
292 | if (!prev || !(prev->vm_flags &VM_GROWSUP))
| ^~~~arch/parisc/mm/fault.c:292:22: note: each undeclared identifier is reported only once for each function it appears in
This is now fixed in Linus's tree with ea3f8272876f ("parisc: fix expand_stack() conversion"), so I'll queue it up and push out yet-another-rc...
thanks,
greg k-h