3.4.102-stable review

This is the start of the stable review cycle for the 3.4.102 release. There are 19 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 Thu Aug 7 18:29:24 UTC 2014. Anything received after that time might be too late.

The whole patch series can be found in one patch at:

	kernel.org/pub/linux/kernel/v3.0/stable-review/patch-3.4.102-rc1.gz

and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <[email protected]>

    Linux 3.4.102-rc1

Gao feng <[email protected]>
ipv6: reallocate addrconf router for ipv6 address when lo device up

Vlastimil Babka <[email protected]>
mm: try_to_unmap_cluster() should lock_page() before mlocking

Boris Ostrovsky <[email protected]>
x86/espfix/xen: Fix allocation of pages for paravirt page tables

Minfei Huang <[email protected]>
lib/btree.c: fix leak of whole btree nodes

Sasha Levin <[email protected]>
net/l2tp: don't fall back on UDP [get|set]sockopt

Greg Kroah-Hartman <[email protected]>
Revert: "net: ip, ipv6: handle gso skbs in forwarding path"

Andy Lutomirski <[email protected]>
x86_64/entry/xen: Do not invoke espfix64 on Xen

H. Peter Anvin <[email protected]>
x86, espfix: Make it possible to disable 16-bit support

H. Peter Anvin <[email protected]>
x86, espfix: Make espfix64 a Kconfig option, fix UML

H. Peter Anvin <[email protected]>
x86, espfix: Fix broken header guard

H. Peter Anvin <[email protected]>
x86, espfix: Move espfix definitions into a separate header file

H. Peter Anvin <[email protected]>
x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack

H. Peter Anvin <[email protected]>
Revert "x86-64, modify_ldt: Make support for 16-bit segments a runtime option"

Jan Kara <[email protected]>
timer: Fix lock inversion between hrtimer_bases.lock and scheduler locks

John Stultz <[email protected]>
printk: rename printk_sched to printk_deferred

David Rientjes <[email protected]>
mm, thp: do not allow thp faults to avoid cpuset restrictions

James Bottomley <[email protected]>
scsi: handle flush errors properly

Konstantin Khlebnikov <[email protected]>
ARM: 8115/1: LPAE: reduce damage caused by idmap to virtual memory layout

Milan Broz <[email protected]>
crypto: af_alg - properly label AF_ALG socket

-------------

Diffstat:

 Documentation/x86/x86_64/mm.txt         |   2 +
 Makefile                                |   4 +-
 arch/arm/mm/idmap.c                     |   7 ++
 arch/x86/Kconfig                        |  25 +++-
 arch/x86/include/asm/espfix.h           |  16 +++
 arch/x86/include/asm/irqflags.h         |   2 +-
 arch/x86/include/asm/pgtable_64_types.h |   2 +
 arch/x86/include/asm/setup.h            |   2 +
 arch/x86/kernel/Makefile                |   1 +
 arch/x86/kernel/entry_32.S              |  12 ++
 arch/x86/kernel/entry_64.S              |  80 ++++++++++--
 arch/x86/kernel/espfix_64.c             | 208 ++++++++++++++++++++++++++++++++
 arch/x86/kernel/ldt.c                   |  10 +-
 arch/x86/kernel/paravirt_patch_64.c     |   2 -
 arch/x86/kernel/smpboot.c               |   7 ++
 arch/x86/mm/dump_pagetables.c           |  31 +++--
 arch/x86/vdso/vdso32-setup.c            |   8 --
 crypto/af_alg.c                         |   2 +
 drivers/scsi/scsi_lib.c                 |   8 ++
 include/linux/printk.h                  |   6 +-
 include/linux/skbuff.h                  |  17 ---
 init/main.c                             |   4 +
 kernel/printk.c                         |   2 +-
 kernel/sched/core.c                     |   2 +-
 kernel/sched/rt.c                       |   2 +-
 kernel/time/clockevents.c               |  10 +-
 lib/btree.c                             |   1 +
 mm/mlock.c                              |   2 +
 mm/page_alloc.c                         |  16 +--
 mm/rmap.c                               |  14 ++-
 net/ipv4/ip_forward.c                   |  68 +----------
 net/ipv6/addrconf.c                     |  14 ++-
 net/ipv6/ip6_output.c                   |  13 +-
 net/l2tp/l2tp_ppp.c                     |   4 +-
 34 files changed, 439 insertions(+), 165 deletions(-)

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Milan Broz <[email protected]>

commit 4c63f83c2c2e16a13ce274ee678e28246bd33645 upstream.

Th AF_ALG socket was missing a security label (e.g. SELinux) which means that socket was in "unlabeled" state.

This was recently demonstrated in the cryptsetup package (cryptsetup v1.6.5 and later.)
See https://bugzilla.redhat.com/show_bug.cgi?id=1115120

This patch clones the sock's label from the parent sock and resolves the issue (similar to AF_BLUETOOTH protocol family).

---
 crypto/af_alg.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -21,6 +21,7 @@
 #include <linux/module.h>
 #include <linux/net.h>
 #include <linux/rwsem.h>
+#include <linux/security.h>
 
 struct alg_type_list {
 	const struct af_alg_type *type;

@@ -243,6 +244,7 @@ int af_alg_accept(struct sock *sk, struc
 
 	sock_init_data(newsock, sk2);
 	sock_graft(sk2, newsock);
+	security_sk_clone(sk, sk2);
 
 	err = type->accept(ask->private, sk2);
 	if (err) {

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Konstantin Khlebnikov <[email protected]>

commit 811a2407a3cf7bbd027fbe92d73416f17485a3d8 upstream.

On LPAE, each level 1 (pgd) page table entry maps 1GiB, and the level 2 (pmd) entries map 2MiB.

When the identity mapping is created on LPAE, the pgd pointers are copied from the swapper_pg_dir. If we find that we need to modify the contents of a pmd, we allocate a new empty pmd table and insert it into the appropriate 1GB slot, before then filling it with the identity mapping.

However, if the 1GB slot covers the kernel lowmem mappings, we obliterate those mappings.

When replacing a PMD, first copy the old PMD contents to the new PMD, so that we preserve the existing mappings, particularly the mappings of the kernel itself.

[rewrote commit message and added code comment -- rmk]

---
 arch/arm/mm/idmap.c |    7 +++++++
 1 file changed, 7 insertions(+)

@@ -22,6 +22,13 @@ static void idmap_add_pmd(pud_t *pud, un
 			pr_warning("Failed to allocate identity pmd.\n");
 			return;
 		}
+		/*
+		 * Copy the original PMD to ensure that the PMD entries for
+		 * the kernel image are preserved.
+		 */
+		if (!pud_none(*pud))
+			memcpy(pmd, pmd_offset(pud, 0),
+			       PTRS_PER_PMD * sizeof(pmd_t));
 		pud_populate(&init_mm, pud, pmd);
 		pmd += pmd_index(addr);
 	} else

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: James Bottomley <[email protected]>

commit 89fb4cd1f717a871ef79fa7debbe840e3225cd54 upstream.

Flush commands don't transfer data and thus need to be special cased in the I/O completion handler so that we can propagate errors to the block layer and filesystem.

---
 drivers/scsi/scsi_lib.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -795,6 +795,14 @@ void scsi_io_completion(struct scsi_cmnd
 			scsi_next_command(cmd);
 			return;
 		}
+	} else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
+		/*
+		 * Certain non BLOCK_PC requests are commands that don't
+		 * actually transfer anything (FLUSH), so cannot use
+		 * good_bytes != blk_rq_bytes(req) as the signal for an error.
+		 * This sets the error explicitly for the problem case.
+		 */
+		error = __scsi_error_from_host_byte(cmd, result);
 	}
 
 	/* no bidi support for !REQ_TYPE_BLOCK_PC yet */

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: David Rientjes <[email protected]>

commit b104a35d32025ca740539db2808aa3385d0f30eb upstream.

The page allocator relies on __GFP_WAIT to determine if ALLOC_CPUSET should be set in allocflags. ALLOC_CPUSET controls if a page allocation should be restricted only to the set of allowed cpuset mems.

Transparent hugepages clears __GFP_WAIT when defrag is disabled to prevent the fault path from using memory compaction or direct reclaim. Thus, it is unfairly able to allocate outside of its cpuset mems restriction as a side-effect.

This patch ensures that ALLOC_CPUSET is only cleared when the gfp mask is truly GFP_ATOMIC by verifying it is also not a thp allocation.

---
 mm/page_alloc.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

@@ -2187,7 +2187,7 @@ static inline int
 gfp_to_alloc_flags(gfp_t gfp_mask)
 {
 	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
-	const gfp_t wait = gfp_mask & __GFP_WAIT;
+	const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
 
 	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
 	BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);

@@ -2196,20 +2196,20 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
 	 * The caller may dip into page reserves a bit more if the caller
 	 * cannot run direct reclaim, or if the caller has realtime scheduling
 	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
-	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
+	 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
 	 */
 	alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
 
-	if (!wait) {
+	if (atomic) {
 		/*
-		 * Not worth trying to allocate harder for
-		 * __GFP_NOMEMALLOC even if it can't schedule.
+		 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
+		 * if it can't schedule.
 		 */
-		if  (!(gfp_mask & __GFP_NOMEMALLOC))
+		if (!(gfp_mask & __GFP_NOMEMALLOC))
 			alloc_flags |= ALLOC_HARDER;
 		/*
-		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
-		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
+		 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
+		 * comment for __cpuset_node_allowed_softwall().
 		 */
 		alloc_flags &= ~ALLOC_CPUSET;
 	} else if (unlikely(rt_task(current)) && !in_interrupt())

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: John Stultz <[email protected]>

commit aac74dc495456412c4130a1167ce4beb6c1f0b38 upstream.

After learning we'll need some sort of deferred printk functionality in the timekeeping core, Peter suggested we rename the printk_sched function so it can be reused by needed subsystems.

This only changes the function name. No logic changes.

---
 include/linux/printk.h |    6 +++---
 kernel/printk.c        |    2 +-
 kernel/sched/core.c    |    2 +-
 kernel/sched/rt.c      |    2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

@@ -101,9 +101,9 @@ asmlinkage __printf(1, 2) __cold
 int printk(const char *fmt, ...);
 
 /*
- * Special printk facility for scheduler use only, _DO_NOT_USE_ !
+ * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
  */
-__printf(1, 2) __cold int printk_sched(const char *fmt, ...);
+__printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
 
 /*
  * Please don't use printk_ratelimit(), because it shares ratelimiting state

@@ -133,7 +133,7 @@ int printk(const char *s, ...)
 	return 0;
 }
 static inline __printf(1, 2) __cold
-int printk_sched(const char *s, ...)
+int printk_deferred(const char *s, ...)
 {
 	return 0;
 }

@@ -1653,7 +1653,7 @@ late_initcall(printk_late_init);
 
 #if defined CONFIG_PRINTK
 
-int printk_sched(const char *fmt, ...)
+int printk_deferred(const char *fmt, ...)
 {
 	unsigned long flags;
 	va_list args;

@@ -1313,7 +1313,7 @@ out:
 		 * leave kernel.
 		 */
 		if (p->mm && printk_ratelimit()) {
-			printk_sched("process %d (%s) no longer affine to cpu%d\n",
+			printk_deferred("process %d (%s) no longer affine to cpu%d\n",
 					task_pid_nr(p), p->comm, cpu);
 		}
 	}

@@ -884,7 +884,7 @@ static int sched_rt_runtime_exceeded(str
 
 			if (!once) {
 				once = true;
-				printk_sched("sched: RT throttling activated\n");
+				printk_deferred("sched: RT throttling activated\n");
 			}
 		} else {
 			/*

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jan Kara <[email protected]>

commit 504d58745c9ca28d33572e2d8a9990b43e06075d upstream.

clockevents_increase_min_delta() calls printk() from under hrtimer_bases.lock. That causes lock inversion on scheduler locks because printk() can call into the scheduler. Lockdep puts it as:

======================================================
[ INFO: possible circular locking dependency detected ] 3.15.0-rc8-06195-g939f04b #2 Not tainted
-------------------------------------------------------
trinity-main/74 is trying to acquire lock:
(&port_lock_key){-.....}, at: [<811c60be>] serial8250_console_write+0x8c/0x10c

but task is already holding lock:
(hrtimer_bases.lock){-.-...}, at: [<8103caeb>] hrtimer_try_to_cancel+0x13/0x66

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #5 (hrtimer_bases.lock){-.-...}:

       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<8103c918>] __hrtimer_start_range_ns+0x1c/0x197
       [<8107ec20>] perf_swevent_start_hrtimer.part.41+0x7a/0x85
       [<81080792>] task_clock_event_start+0x3a/0x3f
       [<810807a4>] task_clock_event_add+0xd/0x14
       [<8108259a>] event_sched_in+0xb6/0x17a
       [<810826a2>] group_sched_in+0x44/0x122
       [<81082885>] ctx_sched_in.isra.67+0x105/0x11f
       [<810828e6>] perf_event_sched_in.isra.70+0x47/0x4b
       [<81082bf6>] __perf_install_in_context+0x8b/0xa3
       [<8107eb8e>] remote_function+0x12/0x2a
       [<8105f5af>] smp_call_function_single+0x2d/0x53
       [<8107e17d>] task_function_call+0x30/0x36
       [<8107fb82>] perf_install_in_context+0x87/0xbb
       [<810852c9>] SYSC_perf_event_open+0x5c6/0x701
       [<810856f9>] SyS_perf_event_open+0x17/0x19
       [<8142f8ee>] syscall_call+0x7/0xb

-> #4 (&ctx->lock){......}:

       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f04c>] _raw_spin_lock+0x21/0x30
       [<81081df3>] __perf_event_task_sched_out+0x1dc/0x34f
       [<8142cacc>] __schedule+0x4c6/0x4cb
       [<8142cae0>] schedule+0xf/0x11
       [<8142f9a6>] work_resched+0x5/0x30

-> #3 (&rq->lock){-.-.-.}:

       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f04c>] _raw_spin_lock+0x21/0x30
       [<81040873>] __task_rq_lock+0x33/0x3a
       [<8104184c>] wake_up_new_task+0x25/0xc2
       [<8102474b>] do_fork+0x15c/0x2a0
       [<810248a9>] kernel_thread+0x1a/0x1f
       [<814232a2>] rest_init+0x1a/0x10e
       [<817af949>] start_kernel+0x303/0x308
       [<817af2ab>] i386_start_kernel+0x79/0x7d

-> #2 (&p->pi_lock){-.-...}:

       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<810413dd>] try_to_wake_up+0x1d/0xd6
       [<810414cd>] default_wake_function+0xb/0xd
       [<810461f3>] __wake_up_common+0x39/0x59
       [<81046346>] __wake_up+0x29/0x3b
       [<811b8733>] tty_wakeup+0x49/0x51
       [<811c3568>] uart_write_wakeup+0x17/0x19
       [<811c5dc1>] serial8250_tx_chars+0xbc/0xfb
       [<811c5f28>] serial8250_handle_irq+0x54/0x6a
       [<811c5f57>] serial8250_default_handle_irq+0x19/0x1c
       [<811c56d8>] serial8250_interrupt+0x38/0x9e
       [<810510e7>] handle_irq_event_percpu+0x5f/0x1e2
       [<81051296>] handle_irq_event+0x2c/0x43
       [<81052cee>] handle_level_irq+0x57/0x80
       [<81002a72>] handle_irq+0x46/0x5c
       [<810027df>] do_IRQ+0x32/0x89
       [<8143036e>] common_interrupt+0x2e/0x33
       [<8142f23c>] _raw_spin_unlock_irqrestore+0x3f/0x49
       [<811c25a4>] uart_start+0x2d/0x32
       [<811c2c04>] uart_write+0xc7/0xd6
       [<811bc6f6>] n_tty_write+0xb8/0x35e
       [<811b9beb>] tty_write+0x163/0x1e4
       [<811b9cd9>] redirected_tty_write+0x6d/0x75
       [<810b6ed6>] vfs_write+0x75/0xb0
       [<810b7265>] SyS_write+0x44/0x77
       [<8142f8ee>] syscall_call+0x7/0xb

-> #1 (&tty->write_wait){-.....}:

       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<81046332>] __wake_up+0x15/0x3b
       [<811b8733>] tty_wakeup+0x49/0x51
       [<811c3568>] uart_write_wakeup+0x17/0x19
       [<811c5dc1>] serial8250_tx_chars+0xbc/0xfb
       [<811c5f28>] serial8250_handle_irq+0x54/0x6a
       [<811c5f57>] serial8250_default_handle_irq+0x19/0x1c
       [<811c56d8>] serial8250_interrupt+0x38/0x9e
       [<810510e7>] handle_irq_event_percpu+0x5f/0x1e2
       [<81051296>] handle_irq_event+0x2c/0x43
       [<81052cee>] handle_level_irq+0x57/0x80
       [<81002a72>] handle_irq+0x46/0x5c
       [<810027df>] do_IRQ+0x32/0x89
       [<8143036e>] common_interrupt+0x2e/0x33
       [<8142f23c>] _raw_spin_unlock_irqrestore+0x3f/0x49
       [<811c25a4>] uart_start+0x2d/0x32
       [<811c2c04>] uart_write+0xc7/0xd6
       [<811bc6f6>] n_tty_write+0xb8/0x35e
       [<811b9beb>] tty_write+0x163/0x1e4
       [<811b9cd9>] redirected_tty_write+0x6d/0x75
       [<810b6ed6>] vfs_write+0x75/0xb0
       [<810b7265>] SyS_write+0x44/0x77
       [<8142f8ee>] syscall_call+0x7/0xb

-> #0 (&port_lock_key){-.....}:

       [<8104a62d>] __lock_acquire+0x9ea/0xc6d
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<811c60be>] serial8250_console_write+0x8c/0x10c
       [<8104e402>] call_console_drivers.constprop.31+0x87/0x118
       [<8104f5d5>] console_unlock+0x1d7/0x398
       [<8104fb70>] vprintk_emit+0x3da/0x3e4
       [<81425f76>] printk+0x17/0x19
       [<8105bfa0>] clockevents_program_min_delta+0x104/0x116
       [<8105c548>] clockevents_program_event+0xe7/0xf3
       [<8105cc1c>] tick_program_event+0x1e/0x23
       [<8103c43c>] hrtimer_force_reprogram+0x88/0x8f
       [<8103c49e>] __remove_hrtimer+0x5b/0x79
       [<8103cb21>] hrtimer_try_to_cancel+0x49/0x66
       [<8103cb4b>] hrtimer_cancel+0xd/0x18
       [<8107f102>] perf_swevent_cancel_hrtimer.part.60+0x2b/0x30
       [<81080705>] task_clock_event_stop+0x20/0x64
       [<81080756>] task_clock_event_del+0xd/0xf
       [<81081350>] event_sched_out+0xab/0x11e
       [<810813e0>] group_sched_out+0x1d/0x66
       [<81081682>] ctx_sched_out+0xaf/0xbf
       [<81081e04>] __perf_event_task_sched_out+0x1ed/0x34f
       [<8142cacc>] __schedule+0x4c6/0x4cb
       [<8142cae0>] schedule+0xf/0x11
       [<8142f9a6>] work_resched+0x5/0x30

other info that might help us debug this:

Chain exists of:
  &port_lock_key --> &ctx->lock --> hrtimer_bases.lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(hrtimer_bases.lock);
                               lock(&ctx->lock);
                               lock(hrtimer_bases.lock);

lock(&port_lock_key);

*** DEADLOCK ***

4 locks held by trinity-main/74:

 #0:  (&rq->lock){-.-.-.}, at: [<8142c6f3>] __schedule+0xed/0x4cb
 #1:  (&ctx->lock){......}, at: [<81081df3>] __perf_event_task_sched_out+0x1dc/0x34f
 #2:  (hrtimer_bases.lock){-.-...}, at: [<8103caeb>] hrtimer_try_to_cancel+0x13/0x66
 #3:  (console_lock){+.+...}, at: [<8104fb5d>] vprintk_emit+0x3c7/0x3e4

stack backtrace:
CPU: 0 PID: 74 Comm: trinity-main Not tainted 3.15.0-rc8-06195-g939f04b #2
 00000000 81c3a310 8b995c14 81426f69 8b995c44 81425a99 8161f671 8161f570
 8161f538 8161f559 8161f538 8b995c78 8b142bb0 00000004 8b142fdc 8b142bb0
 8b995ca8 8104a62d 8b142fac 000016f2 81c3a310 00000001 00000001 00000003
Call Trace:
 [<81426f69>] dump_stack+0x16/0x18
 [<81425a99>] print_circular_bug+0x18f/0x19c
 [<8104a62d>] __lock_acquire+0x9ea/0xc6d
 [<8104a942>] lock_acquire+0x92/0x101
 [<811c60be>] ? serial8250_console_write+0x8c/0x10c
 [<811c6032>] ? wait_for_xmitr+0x76/0x76
 [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
 [<811c60be>] ? serial8250_console_write+0x8c/0x10c
 [<811c60be>] serial8250_console_write+0x8c/0x10c
 [<8104af87>] ? lock_release+0x191/0x223
 [<811c6032>] ? wait_for_xmitr+0x76/0x76
 [<8104e402>] call_console_drivers.constprop.31+0x87/0x118
 [<8104f5d5>] console_unlock+0x1d7/0x398
 [<8104fb70>] vprintk_emit+0x3da/0x3e4
 [<81425f76>] printk+0x17/0x19
 [<8105bfa0>] clockevents_program_min_delta+0x104/0x116
 [<8105cc1c>] tick_program_event+0x1e/0x23
 [<8103c43c>] hrtimer_force_reprogram+0x88/0x8f
 [<8103c49e>] __remove_hrtimer+0x5b/0x79
 [<8103cb21>] hrtimer_try_to_cancel+0x49/0x66
 [<8103cb4b>] hrtimer_cancel+0xd/0x18
 [<8107f102>] perf_swevent_cancel_hrtimer.part.60+0x2b/0x30
 [<81080705>] task_clock_event_stop+0x20/0x64
 [<81080756>] task_clock_event_del+0xd/0xf
 [<81081350>] event_sched_out+0xab/0x11e
 [<810813e0>] group_sched_out+0x1d/0x66
 [<81081682>] ctx_sched_out+0xaf/0xbf
 [<81081e04>] __perf_event_task_sched_out+0x1ed/0x34f
 [<8104416d>] ? __dequeue_entity+0x23/0x27
 [<81044505>] ? pick_next_task_fair+0xb1/0x120
 [<8142cacc>] __schedule+0x4c6/0x4cb
 [<81047574>] ? trace_hardirqs_off_caller+0xd7/0x108
 [<810475b0>] ? trace_hardirqs_off+0xb/0xd
 [<81056346>] ? rcu_irq_exit+0x64/0x77

Fix the problem by using printk_deferred() which does not call into the scheduler.

---
 kernel/time/clockevents.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -143,7 +143,8 @@ static int clockevents_increase_min_delt
 {
 	/* Nothing to do if we already reached the limit */
 	if (dev->min_delta_ns >= MIN_DELTA_LIMIT) {
-		printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n");
+		printk_deferred(KERN_WARNING
+				"CE: Reprogramming failure. Giving up\n");
 		dev->next_event.tv64 = KTIME_MAX;
 		return -ETIME;
 	}

@@ -156,9 +157,10 @@ static int clockevents_increase_min_delt
 	if (dev->min_delta_ns > MIN_DELTA_LIMIT)
 		dev->min_delta_ns = MIN_DELTA_LIMIT;
 
-	printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n",
-	       dev->name ? dev->name : "?",
-	       (unsigned long long) dev->min_delta_ns);
+	printk_deferred(KERN_WARNING
+			"CE: %s increased min_delta_ns to %llu nsec\n",
+			dev->name ? dev->name : "?",
+			(unsigned long long) dev->min_delta_ns);
 	return 0;
 }
 

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "H. Peter Anvin" <[email protected]>

commit 7ed6fb9b5a5510e4ef78ab27419184741169978a upstream.

This reverts commit fa81511bb0bbb2b1aace3695ce869da9762624ff in preparation of merging in the proper fix (espfix64).

---
 arch/x86/kernel/ldt.c        |    4 +---
 arch/x86/vdso/vdso32-setup.c |    8 --------
 2 files changed, 1 insertion(+), 11 deletions(-)

@@ -20,8 +20,6 @@
 #include <asm/mmu_context.h>
 #include <asm/syscalls.h>
 
-int sysctl_ldt16 = 0;
-
 #ifdef CONFIG_SMP
 static void flush_ldt(void *current_mm)
 {

@@ -236,7 +234,7 @@ static int write_ldt(void __user *ptr, u
 	 * IRET leaking the high bits of the kernel stack address.
 	 */
 #ifdef CONFIG_X86_64
-	if (!ldt_info.seg_32bit && !sysctl_ldt16) {
+	if (!ldt_info.seg_32bit) {
 		error = -EINVAL;
 		goto out_unlock;
 	}

@@ -41,7 +41,6 @@ enum {
 #ifdef CONFIG_X86_64
 #define vdso_enabled			sysctl_vsyscall32
 #define arch_setup_additional_pages	syscall32_setup_pages
-extern int sysctl_ldt16;
 #endif
 
 /*

@@ -380,13 +379,6 @@ static ctl_table abi_table2[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
-	},
-	{
-		.procname	= "ldt16",
-		.data		= &sysctl_ldt16,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
 	},
 	{}
 };

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "H. Peter Anvin" <[email protected]>

commit 3891a04aafd668686239349ea58f3314ea2af86b upstream.

The IRET instruction, when returning to a 16-bit segment, only restores the bottom 16 bits of the user space stack pointer. This causes some 16-bit software to break, but it also leaks kernel state to user space. We have a software workaround for that ("espfix") for the 32-bit kernel, but it relies on a nonzero stack segment base which is not available in 64-bit mode.

In checkin:

    b3b42ac2cbae x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels

we "solved" this by forbidding 16-bit segments on 64-bit kernels, with the logic that 16-bit support is crippled on 64-bit kernels anyway (no V86 support), but it turns out that people are doing stuff like running old Win16 binaries under Wine and expect it to work.

This works around this by creating percpu "ministacks", each of which is mapped 2^16 times 64K apart. When we detect that the return SS is on the LDT, we copy the IRET frame to the ministack and use the relevant alias to return to userspace. The ministacks are mapped readonly, so if IRET faults we promote #GP to #DF which is an IST vector and thus has its own stack; we then do the fixup in the #DF handler.

(Making #GP an IST exception would make the msr_safe functions unsafe in NMI/MC context, and quite possibly have other effects.)

Special thanks to:

- Andy Lutomirski, for the suggestion of using very small stack slots and copy (as opposed to map) the IRET frame there, and for the suggestion to mark them readonly and let the fault promote to #DF.
- Konrad Wilk for paravirt fixup and testing.
- Borislav Petkov for testing help and useful comments.

---
 Documentation/x86/x86_64/mm.txt         |    2 
 arch/x86/include/asm/pgtable_64_types.h |    2 
 arch/x86/include/asm/setup.h            |    3 
 arch/x86/kernel/Makefile                |    1 
 arch/x86/kernel/entry_64.S              |   73 ++++++++++-
 arch/x86/kernel/espfix_64.c             |  208 ++++++++++++++++++++++++++++++++
 arch/x86/kernel/ldt.c                   |   11 -
 arch/x86/kernel/smpboot.c               |    7 +
 arch/x86/mm/dump_pagetables.c           |   31 +++-
 init/main.c                             |    4 
 10 files changed, 316 insertions(+), 26 deletions(-)

@@ -12,6 +12,8 @@ ffffc90000000000 - ffffe8ffffffffff (=45
 ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole
 ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB)
 ... unused hole ...
+ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
+... unused hole ...
 ffffffff80000000 - ffffffffa0000000 (=512 MB)  kernel text mapping, from phys 0
 ffffffffa0000000 - fffffffffff00000 (=1536 MB) module mapping space
 

@@ -59,5 +59,7 @@ typedef struct { pteval_t pte; } pte_t;
 #define MODULES_VADDR    _AC(0xffffffffa0000000, UL)
 #define MODULES_END      _AC(0xffffffffff000000, UL)
 #define MODULES_LEN   (MODULES_END - MODULES_VADDR)
+#define ESPFIX_PGD_ENTRY _AC(-2, UL)
+#define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT)
 
 #endif /* _ASM_X86_PGTABLE_64_DEFS_H */

@@ -59,6 +59,9 @@ extern void x86_ce4100_early_setup(void)
 static inline void x86_ce4100_early_setup(void) { }
 #endif
 
+extern void init_espfix_bsp(void);
+extern void init_espfix_ap(void);
+
 #ifndef _SETUP
 
 /*

@@ -28,6 +28,7 @@ obj-$(CONFIG_X86_64)	+= sys_x86_64.o x86
 obj-y			+= syscall_$(BITS).o
 obj-$(CONFIG_X86_64)	+= vsyscall_64.o
 obj-$(CONFIG_X86_64)	+= vsyscall_emu_64.o
+obj-$(CONFIG_X86_64)	+= espfix_64.o
 obj-y			+= bootflag.o e820.o
 obj-y			+= pci-dma.o quirks.o topology.o kdebugfs.o
 obj-y			+= alternative.o i8253.o pci-nommu.o hw_breakpoint.o

@@ -229,17 +229,6 @@ static int write_ldt(void __user *ptr, u
 		}
 	}
 
-	/*
-	 * On x86-64 we do not support 16-bit segments due to
-	 * IRET leaking the high bits of the kernel stack address.
-	 */
-#ifdef CONFIG_X86_64
-	if (!ldt_info.seg_32bit) {
-		error = -EINVAL;
-		goto out_unlock;
-	}
-#endif
-
 	fill_ldt(&ldt, &ldt_info);
 	if (oldmode)
 		ldt.avl = 0;

@@ -271,6 +271,13 @@ notrace static void __cpuinit start_seco
 	check_tsc_sync_target();
 
 	/*
+	 * Enable the espfix hack for this CPU
+	 */
+#ifdef CONFIG_X86_64
+	init_espfix_ap();
+#endif
+
+	/*
 	 * We need to hold call_lock, so there is no inconsistency
 	 * between the time smp_call_function() determines number of
 	 * IPI recipients, and the time when the determination is made

@@ -30,11 +30,13 @@ struct pg_state {
 	unsigned long start_address;
 	unsigned long current_address;
 	const struct addr_marker *marker;
+	unsigned long lines;
 };
 
 struct addr_marker {
 	unsigned long start_address;
 	const char *name;
+	unsigned long max_lines;
 };
 
 /* indices for address_markers; keep sync'd w/ address_markers below */

@@ -45,6 +47,7 @@ enum address_markers_idx {
 	LOW_KERNEL_NR,
 	VMALLOC_START_NR,
 	VMEMMAP_START_NR,
+	ESPFIX_START_NR,
 	HIGH_KERNEL_NR,
 	MODULES_VADDR_NR,
 	MODULES_END_NR,

@@ -67,6 +70,7 @@ static struct addr_marker address_marker
 	{ PAGE_OFFSET,		"Low Kernel Mapping" },
 	{ VMALLOC_START,        "vmalloc() Area" },
 	{ VMEMMAP_START,        "Vmemmap" },
+	{ ESPFIX_BASE_ADDR,	"ESPfix Area", 16 },
 	{ __START_KERNEL_map,   "High Kernel Mapping" },
 	{ MODULES_VADDR,        "Modules" },
 	{ MODULES_END,          "End Modules" },

@@ -163,7 +167,7 @@ static void note_page(struct seq_file *m
 		      pgprot_t new_prot, int level)
 {
 	pgprotval_t prot, cur;
-	static const char units[] = "KMGTPE";
+	static const char units[] = "BKMGTPE";
 
 	/*
 	 * If we have a "break" in the series, we need to flush the state that

@@ -178,6 +182,7 @@ static void note_page(struct seq_file *m
 		st->current_prot = new_prot;
 		st->level = level;
 		st->marker = address_markers;
+		st->lines = 0;
 		seq_printf(m, "---[ %s ]---\n", st->marker->name);
 	} else if (prot != cur || level != st->level ||
 		   st->current_address >= st->marker[1].start_address) {

@@ -188,17 +193,21 @@ static void note_page(struct seq_file *m
 		/*
 		 * Now print the actual finished series
 		 */
-		seq_printf(m, "0x%0*lx-0x%0*lx   ",
-			   width, st->start_address,
-			   width, st->current_address);
-
-		delta = (st->current_address - st->start_address) >> 10;
-		while (!(delta & 1023) && unit[1]) {
-			delta >>= 10;
-			unit++;
+		if (!st->marker->max_lines ||
+		    st->lines < st->marker->max_lines) {
+			seq_printf(m, "0x%0*lx-0x%0*lx   ",
+				   width, st->start_address,
+				   width, st->current_address);
+
+			delta = (st->current_address - st->start_address) >> 10;
+			while (!(delta & 1023) && unit[1]) {
+				delta >>= 10;
+				unit++;
+			}
+			seq_printf(m, "%9lu%c ", delta, *unit);
+			printk_prot(m, st->current_prot, st->level);
 		}
-		seq_printf(m, "%9lu%c ", delta, *unit);
-		printk_prot(m, st->current_prot, st->level);
+		st->lines++;
 
 		/*
 		 * We print markers for special areas of address space,

@@ -606,6 +606,10 @@ asmlinkage void __init start_kernel(void
 	if (efi_enabled(EFI_RUNTIME_SERVICES))
 		efi_enter_virtual_mode();
 #endif
+#ifdef CONFIG_X86_64
+	/* Should be run before the first non-init thread is created */
+	init_espfix_bsp();
+#endif
 	thread_info_cache_init();
 	cred_init();
 	fork_init(totalram_pages);

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "H. Peter Anvin" <[email protected]>

commit e1fe9ed8d2a4937510d0d60e20705035c2609aea upstream.

Sparse warns that the percpu variables aren't declared before they are defined. Rather than hacking around it, move espfix definitions into a proper header file.

---
 arch/x86/include/asm/espfix.h |   16 ++++++++++++++++
 arch/x86/include/asm/setup.h  |    5 ++---
 arch/x86/kernel/espfix_64.c   |    1 +
 3 files changed, 19 insertions(+), 3 deletions(-)

@@ -0,0 +1,16 @@
+#ifdef _ASM_X86_ESPFIX_H
+#define _ASM_X86_ESPFIX_H
+
+#ifdef CONFIG_X86_64
+
+#include <asm/percpu.h>
+
+DECLARE_PER_CPU_READ_MOSTLY(unsigned long, espfix_stack);
+DECLARE_PER_CPU_READ_MOSTLY(unsigned long, espfix_waddr);
+
+extern void init_espfix_bsp(void);
+extern void init_espfix_ap(void);
+
+#endif /* CONFIG_X86_64 */
+
+#endif /* _ASM_X86_ESPFIX_H */

@@ -59,11 +59,10 @@ extern void x86_ce4100_early_setup(void)
 static inline void x86_ce4100_early_setup(void) { }
 #endif
 
-extern void init_espfix_bsp(void);
-extern void init_espfix_ap(void);
-
 #ifndef _SETUP
 
+#include <asm/espfix.h>
+
 /*
  * This is set up by the setup-routine at boot-time
  */

@@ -40,6 +40,7 @@
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/setup.h>
+#include <asm/espfix.h>
 
 /*
  * Note: we only need 6*8 = 48 bytes for the espfix stack, but round

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "H. Peter Anvin" <[email protected]>

commit 20b68535cd27183ebd3651ff313afb2b97dac941 upstream.

Header guard is #ifndef, not #ifdef...

---
 arch/x86/include/asm/espfix.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -1,4 +1,4 @@
-#ifdef _ASM_X86_ESPFIX_H
+#ifndef _ASM_X86_ESPFIX_H
 #define _ASM_X86_ESPFIX_H
 
 #ifdef CONFIG_X86_64

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "H. Peter Anvin" <[email protected]>

commit 197725de65477bc8509b41388157c1a2283542bb upstream.

Make espfix64 a hidden Kconfig option. This fixes the x86-64 UML build which had broken due to the non-existence of init_espfix_bsp() in UML: since UML uses its own Kconfig, this option does not appear in the UML build.

This also makes it possible to make support for 16-bit segments a configuration option, for the people who want to minimize the size of the kernel.

---
 arch/x86/Kconfig          |    4 ++++
 arch/x86/kernel/Makefile  |    2 +-
 arch/x86/kernel/smpboot.c |    2 +-
 init/main.c               |    2 +-
 4 files changed, 7 insertions(+), 3 deletions(-)

@@ -920,6 +920,10 @@ config VM86
 	  XFree86 to initialize some video cards via BIOS. Disabling this
 	  option saves about 6k.
 
+config X86_ESPFIX64
+	def_bool y
+	depends on X86_64
+
 config TOSHIBA
 	tristate "Toshiba Laptop support"
 	depends on X86_32

@@ -28,7 +28,7 @@ obj-$(CONFIG_X86_64)	+= sys_x86_64.o x86
 obj-y			+= syscall_$(BITS).o
 obj-$(CONFIG_X86_64)	+= vsyscall_64.o
 obj-$(CONFIG_X86_64)	+= vsyscall_emu_64.o
-obj-$(CONFIG_X86_64)	+= espfix_64.o
+obj-$(CONFIG_X86_ESPFIX64)	+= espfix_64.o
 obj-y			+= bootflag.o e820.o
 obj-y			+= pci-dma.o quirks.o topology.o kdebugfs.o
 obj-y			+= alternative.o i8253.o pci-nommu.o hw_breakpoint.o

@@ -273,7 +273,7 @@ notrace static void __cpuinit start_seco
 	/*
 	 * Enable the espfix hack for this CPU
 	 */
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ESPFIX64
 	init_espfix_ap();
 #endif
 

@@ -606,7 +606,7 @@ asmlinkage void __init start_kernel(void
 	if (efi_enabled(EFI_RUNTIME_SERVICES))
 		efi_enter_virtual_mode();
 #endif
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ESPFIX64
 	/* Should be run before the first non-init thread is created */
 	init_espfix_bsp();
 #endif

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "H. Peter Anvin" <[email protected]>

commit 34273f41d57ee8d854dcd2a1d754cbb546cb548f upstream.

Embedded systems, which may be very memory-size-sensitive, are extremely unlikely to ever encounter any 16-bit software, so make it a CONFIG_EXPERT option to turn off support for any 16-bit software whatsoever.

---
 arch/x86/Kconfig           |   23 ++++++++++++++++++-----
 arch/x86/kernel/entry_32.S |   12 ++++++++++++
 arch/x86/kernel/entry_64.S |    8 ++++++++
 arch/x86/kernel/ldt.c      |    5 +++++
 4 files changed, 43 insertions(+), 5 deletions(-)

@@ -915,14 +915,27 @@ config VM86
 	default y
 	depends on X86_32
 	---help---
-	  This option is required by programs like DOSEMU to run 16-bit legacy
-	  code on X86 processors. It also may be needed by software like
-	  XFree86 to initialize some video cards via BIOS. Disabling this
-	  option saves about 6k.
+	  This option is required by programs like DOSEMU to run
+	  16-bit real mode legacy code on x86 processors. It also may
+	  be needed by software like XFree86 to initialize some video
+	  cards via BIOS. Disabling this option saves about 6K.
+
+config X86_16BIT
+	bool "Enable support for 16-bit segments" if EXPERT
+	default y
+	---help---
+	  This option is required by programs like Wine to run 16-bit
+	  protected mode legacy code on x86 processors.  Disabling
+	  this option saves about 300 bytes on i386, or around 6K text
+	  plus 16K runtime memory on x86-64,
+
+config X86_ESPFIX32
+	def_bool y
+	depends on X86_16BIT && X86_32
 
 config X86_ESPFIX64
 	def_bool y
-	depends on X86_64
+	depends on X86_16BIT && X86_64
 
 config TOSHIBA
 	tristate "Toshiba Laptop support"

@@ -525,6 +525,7 @@ syscall_exit:
 restore_all:
 	TRACE_IRQS_IRET
 restore_all_notrace:
+#ifdef CONFIG_X86_ESPFIX32
 	movl PT_EFLAGS(%esp), %eax	# mix EFLAGS, SS and CS
 	# Warning: PT_OLDSS(%esp) contains the wrong/random values if we
 	# are returning to the kernel.

@@ -535,6 +536,7 @@ restore_all_notrace:
 	cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
 	CFI_REMEMBER_STATE
 	je ldt_ss			# returning to user-space with LDT SS
+#endif
 restore_nocheck:
 	RESTORE_REGS 4			# skip orig_eax/error_code
 irq_return:

@@ -550,6 +552,7 @@ ENTRY(iret_exc)
 	.long irq_return,iret_exc
 .previous
 
+#ifdef CONFIG_X86_ESPFIX32
 	CFI_RESTORE_STATE
 ldt_ss:
 #ifdef CONFIG_PARAVIRT

@@ -593,6 +596,7 @@ ldt_ss:
 	lss (%esp), %esp		/* switch to espfix segment */
 	CFI_ADJUST_CFA_OFFSET -8
 	jmp restore_nocheck
+#endif
 	CFI_ENDPROC
 ENDPROC(system_call)
 

@@ -766,6 +770,7 @@ ENDPROC(ptregs_clone)
  * the high word of the segment base from the GDT and swiches to the
  * normal stack and adjusts ESP with the matching offset.
  */
+#ifdef CONFIG_X86_ESPFIX32
 	/* fixup the stack */
 	mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
 	mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */

@@ -775,8 +780,10 @@ ENDPROC(ptregs_clone)
 	pushl_cfi %eax
 	lss (%esp), %esp		/* switch to the normal stack segment */
 	CFI_ADJUST_CFA_OFFSET -8
+#endif
 .endm
 .macro UNWIND_ESPFIX_STACK
+#ifdef CONFIG_X86_ESPFIX32
 	movl %ss, %eax
 	/* see if on espfix stack */
 	cmpw $__ESPFIX_SS, %ax

@@ -787,6 +794,7 @@ ENDPROC(ptregs_clone)
 	/* switch to normal stack */
 	FIXUP_ESPFIX_STACK
 27:
+#endif
 .endm
 
 /*

@@ -1318,11 +1326,13 @@ END(debug)
  */
 ENTRY(nmi)
 	RING0_INT_FRAME
+#ifdef CONFIG_X86_ESPFIX32
 	pushl_cfi %eax
 	movl %ss, %eax
 	cmpw $__ESPFIX_SS, %ax
 	popl_cfi %eax
 	je nmi_espfix_stack
+#endif
 	cmpl $ia32_sysenter_target,(%esp)
 	je nmi_stack_fixup
 	pushl_cfi %eax

@@ -1362,6 +1372,7 @@ nmi_debug_stack_check:
 	FIX_STACK 24, nmi_stack_correct, 1
 	jmp nmi_stack_correct
 
+#ifdef CONFIG_X86_ESPFIX32
 nmi_espfix_stack:
 	/* We have a RING0_INT_FRAME here.
 	 *

@@ -1383,6 +1394,7 @@ nmi_espfix_stack:
 	lss 12+4(%esp), %esp		# back to espfix stack
 	CFI_ADJUST_CFA_OFFSET -24
 	jmp irq_return
+#endif
 	CFI_ENDPROC
 END(nmi)
 

@@ -904,8 +904,10 @@ irq_return:
 	 * Are we returning to a stack segment from the LDT?  Note: in
 	 * 64-bit mode SS:RSP on the exception stack is always valid.
 	 */
+#ifdef CONFIG_X86_ESPFIX64
 	testb $4,(SS-RIP)(%rsp)
 	jnz irq_return_ldt
+#endif
 
 irq_return_iret:
 	INTERRUPT_RETURN

@@ -923,6 +925,7 @@ ENTRY(native_iret)
 	.previous
 #endif
 
+#ifdef CONFIG_X86_ESPFIX64
 irq_return_ldt:
 	pushq_cfi %rax
 	pushq_cfi %rdi

@@ -946,6 +949,7 @@ irq_return_ldt:
 	movq %rax,%rsp
 	popq_cfi %rax
 	jmp irq_return_iret
+#endif
 
 	.section .fixup,"ax"
 bad_iret:

@@ -1019,6 +1023,7 @@ END(common_interrupt)
 	 * modify the stack to make it look like we just entered
 	 * the #GP handler from user space, similar to bad_iret.
 	 */
+#ifdef CONFIG_X86_ESPFIX64
 	ALIGN
 __do_double_fault:
 	XCPT_FRAME 1 RDI+8

@@ -1044,6 +1049,9 @@ __do_double_fault:
 	retq
 	CFI_ENDPROC
 END(__do_double_fault)
+#else
+# define __do_double_fault do_double_fault
+#endif
 
 /*
  * End of kprobes section

@@ -229,6 +229,11 @@ static int write_ldt(void __user *ptr, u
 		}
 	}
 
+	if (!IS_ENABLED(CONFIG_X86_16BIT) && !ldt_info.seg_32bit) {
+		error = -EINVAL;
+		goto out_unlock;
+	}
+
 	fill_ldt(&ldt, &ldt_info);
 	if (oldmode)
 		ldt.avl = 0;

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski <[email protected]>

commit 7209a75d2009dbf7745e2fd354abf25c3deb3ca3 upstream.

This moves the espfix64 logic into native_iret. To make this work, it gets rid of the native patch for INTERRUPT_RETURN:
INTERRUPT_RETURN on native kernels is now 'jmp native_iret'.

This changes the 16-bit SS behavior on Xen from OOPSing to leaking some bits of the Xen hypervisor's RSP (I think).

[ hpa: this is a nonzero cost on native, but probably not enough to
measure. Xen needs to fix this in their own code, probably doing something equivalent to espfix64. ]

---
 arch/x86/include/asm/irqflags.h     |    2 +-
 arch/x86/kernel/entry_64.S          |   31 ++++++++++---------------------
 arch/x86/kernel/paravirt_patch_64.c |    2 --
 3 files changed, 11 insertions(+), 24 deletions(-)

@@ -129,7 +129,7 @@ static inline notrace unsigned long arch
 
 #define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
 
-#define INTERRUPT_RETURN	iretq
+#define INTERRUPT_RETURN	jmp native_iret
 #define USERGS_SYSRET64				\
 	swapgs;					\
 	sysretq;

@@ -900,33 +900,27 @@ restore_args:
 	RESTORE_ARGS 1,8,1
 
 irq_return:
+	INTERRUPT_RETURN
+
+ENTRY(native_iret)
 	/*
 	 * Are we returning to a stack segment from the LDT?  Note: in
 	 * 64-bit mode SS:RSP on the exception stack is always valid.
 	 */
 #ifdef CONFIG_X86_ESPFIX64
 	testb $4,(SS-RIP)(%rsp)
-	jnz irq_return_ldt
+	jnz native_irq_return_ldt
 #endif
 
-irq_return_iret:
-	INTERRUPT_RETURN
-
-	.section __ex_table, "a"
-	.quad irq_return_iret, bad_iret
-	.previous
-
-#ifdef CONFIG_PARAVIRT
-ENTRY(native_iret)
+native_irq_return_iret:
 	iretq
 
 	.section __ex_table,"a"
-	.quad native_iret, bad_iret
+	.quad native_irq_return_iret, bad_iret
 	.previous
-#endif
 
 #ifdef CONFIG_X86_ESPFIX64
-irq_return_ldt:
+native_irq_return_ldt:
 	pushq_cfi %rax
 	pushq_cfi %rdi
 	SWAPGS

@@ -948,7 +942,7 @@ irq_return_ldt:
 	SWAPGS
 	movq %rax,%rsp
 	popq_cfi %rax
-	jmp irq_return_iret
+	jmp native_irq_return_iret
 #endif
 
 	.section .fixup,"ax"

@@ -1034,13 +1028,8 @@ __do_double_fault:
 	cmpl $__KERNEL_CS,CS(%rdi)
 	jne do_double_fault
 	movq RIP(%rdi),%rax
-	cmpq $irq_return_iret,%rax
-#ifdef CONFIG_PARAVIRT
-	je 1f
-	cmpq $native_iret,%rax
-#endif
+	cmpq $native_irq_return_iret,%rax
 	jne do_double_fault		/* This shouldn't happen... */
-1:
 	movq PER_CPU_VAR(kernel_stack),%rax
 	subq $(6*8-KERNEL_STACK_OFFSET),%rax	/* Reset to original stack */
 	movq %rax,RSP(%rdi)

@@ -1559,7 +1548,7 @@ error_sti:
  */
 error_kernelspace:
 	incl %ebx
-	leaq irq_return_iret(%rip),%rcx
+	leaq native_irq_return_iret(%rip),%rcx
 	cmpq %rcx,RIP+8(%rsp)
 	je error_swapgs
 	movl %ecx,%eax	/* zero extend */

@@ -6,7 +6,6 @@ DEF_NATIVE(pv_irq_ops, irq_disable, "cli
 DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
 DEF_NATIVE(pv_irq_ops, restore_fl, "pushq %rdi; popfq");
 DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax");
-DEF_NATIVE(pv_cpu_ops, iret, "iretq");
 DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
 DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
 DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");

@@ -50,7 +49,6 @@ unsigned native_patch(u8 type, u16 clobb
 		PATCH_SITE(pv_irq_ops, save_fl);
 		PATCH_SITE(pv_irq_ops, irq_enable);
 		PATCH_SITE(pv_irq_ops, irq_disable);
-		PATCH_SITE(pv_cpu_ops, iret);
 		PATCH_SITE(pv_cpu_ops, irq_enable_sysexit);
 		PATCH_SITE(pv_cpu_ops, usergs_sysret32);
 		PATCH_SITE(pv_cpu_ops, usergs_sysret64);

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

This reverts commit 29a3cd46644ec8098dbe1c12f89643b5c11831a9 which is commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream.

---
 include/linux/skbuff.h |   17 ------------
 net/ipv4/ip_forward.c  |   68 +------------------------------------------------
 net/ipv6/ip6_output.c  |   13 ---------
 3 files changed, 3 insertions(+), 95 deletions(-)

@@ -2608,22 +2608,5 @@ static inline bool skb_is_recycleable(co
 
 	return true;
 }
-
-/**
- * skb_gso_network_seglen - Return length of individual segments of a gso packet
- *
- * @skb: GSO skb
- *
- * skb_gso_network_seglen is used to determine the real size of the
- * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
- *
- * The MAC/L2 header is not accounted for.
- */
-static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
-{
-	unsigned int hdr_len = skb_transport_header(skb) -
-			       skb_network_header(skb);
-	return hdr_len + skb_gso_transport_seglen(skb);
-}
 #endif	/* __KERNEL__ */
 #endif	/* _LINUX_SKBUFF_H */

@@ -382,17 +382,6 @@ static inline int ip6_forward_finish(str
 	return dst_output(skb);
 }
 
-static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
-{
-	if (skb->len <= mtu || skb->local_df)
-		return false;
-
-	if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
-		return false;
-
-	return true;
-}
-
 int ip6_forward(struct sk_buff *skb)
 {
 	struct dst_entry *dst = skb_dst(skb);

@@ -514,7 +503,7 @@ int ip6_forward(struct sk_buff *skb)
 	if (mtu < IPV6_MIN_MTU)
 		mtu = IPV6_MIN_MTU;
 
-	if (ip6_pkt_too_big(skb, mtu)) {
+	if (skb->len > mtu && !skb_is_gso(skb)) {
 		/* Again, force OUTPUT device used as source address */
 		skb->dev = dst->dev;
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sasha Levin <[email protected]>

commit 3cf521f7dc87c031617fd47e4b7aa2593c2f3daf upstream.

The l2tp [get|set]sockopt() code has fallen back to the UDP functions for socket option levels != SOL_PPPOL2TP since day one, but that has never actually worked, since the l2tp socket isn't an inet socket.

As David Miller points out:

"If we wanted this to work, it'd have to look up the tunnel and then
use tunnel->sk, but I wonder how useful that would be"

Since this can never have worked so nobody could possibly have depended on that functionality, just remove the broken code and return -EINVAL.

---
 net/l2tp/l2tp_ppp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -1351,7 +1351,7 @@ static int pppol2tp_setsockopt(struct so
 	int err;
 
 	if (level != SOL_PPPOL2TP)
-		return udp_prot.setsockopt(sk, level, optname, optval, optlen);
+		return -EINVAL;
 
 	if (optlen < sizeof(int))
 		return -EINVAL;

@@ -1477,7 +1477,7 @@ static int pppol2tp_getsockopt(struct so
 	struct pppol2tp_session *ps;
 
 	if (level != SOL_PPPOL2TP)
-		return udp_prot.getsockopt(sk, level, optname, optval, optlen);
+		return -EINVAL;
 
 	if (get_user(len, (int __user *) optlen))
 		return -EFAULT;

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Minfei Huang <[email protected]>

commit c75b53af2f0043aff500af0a6f878497bef41bca upstream.

I use btree from 3.14-rc2 in my own module. When the btree module is removed, a warning arises:

kmem_cache_destroy btree_node: Slab cache still has objects

 CPU: 13 PID: 9150 Comm: rmmod Tainted: GF          O 3.14.0-rc2 #1
 Hardware name: Inspur NF5270M3/NF5270M3, BIOS CHEETAH_2.1.3 09/10/2013
 Call Trace:
   dump_stack+0x49/0x5d
   kmem_cache_destroy+0xcf/0xe0
   btree_module_exit+0x10/0x12 [btree]
   SyS_delete_module+0x198/0x1f0
   system_call_fastpath+0x16/0x1b

The cause is that it doesn't release the last btree node, when height = 1 and fill = 1.

---
 lib/btree.c |    1 +
 1 file changed, 1 insertion(+)

@@ -198,6 +198,7 @@ EXPORT_SYMBOL_GPL(btree_init);
 
 void btree_destroy(struct btree_head *head)
 {
+	mempool_free(head->node, head->mempool);
 	mempool_destroy(head->mempool);
 	head->mempool = NULL;
 }

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Boris Ostrovsky <[email protected]>

commit 8762e5092828c4dc0f49da5a47a644c670df77f3 upstream.

init_espfix_ap() is currently off by one level when informing hypervisor that allocated pages will be used for ministacks' page tables.

The most immediate effect of this on a PV guest is that if 'stack_page = __get_free_page()' returns a non-zeroed-out page the hypervisor will refuse to use it for a page table (which it shouldn't be anyway). This will result in warnings by both Xen and Linux.

More importantly, a subsequent write to that page (again, by a PV guest) is likely to result in fatal page fault.

---
 arch/x86/kernel/espfix_64.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

@@ -175,7 +175,7 @@ void init_espfix_ap(void)
 	if (!pud_present(pud)) {
 		pmd_p = (pmd_t *)__get_free_page(PGALLOC_GFP);
 		pud = __pud(__pa(pmd_p) | (PGTABLE_PROT & ptemask));
-		paravirt_alloc_pud(&init_mm, __pa(pmd_p) >> PAGE_SHIFT);
+		paravirt_alloc_pmd(&init_mm, __pa(pmd_p) >> PAGE_SHIFT);
 		for (n = 0; n < ESPFIX_PUD_CLONES; n++)
 			set_pud(&pud_p[n], pud);
 	}

@@ -185,7 +185,7 @@ void init_espfix_ap(void)
 	if (!pmd_present(pmd)) {
 		pte_p = (pte_t *)__get_free_page(PGALLOC_GFP);
 		pmd = __pmd(__pa(pte_p) | (PGTABLE_PROT & ptemask));
-		paravirt_alloc_pmd(&init_mm, __pa(pte_p) >> PAGE_SHIFT);
+		paravirt_alloc_pte(&init_mm, __pa(pte_p) >> PAGE_SHIFT);
 		for (n = 0; n < ESPFIX_PMD_CLONES; n++)
 			set_pmd(&pmd_p[n], pmd);
 	}

@@ -193,7 +193,6 @@ void init_espfix_ap(void)
 	pte_p = pte_offset_kernel(&pmd, addr);
 	stack_page = (void *)__get_free_page(GFP_KERNEL);
 	pte = __pte(__pa(stack_page) | (__PAGE_KERNEL_RO & ptemask));
-	paravirt_alloc_pte(&init_mm, __pa(stack_page) >> PAGE_SHIFT);
 	for (n = 0; n < ESPFIX_PTE_CLONES; n++)
 		set_pte(&pte_p[n*PTE_STRIDE], pte);
 

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vlastimil Babka <[email protected]>

commit 57e68e9cd65b4b8eb4045a1e0d0746458502554c upstream.

A BUG_ON(!PageLocked) was triggered in mlock_vma_page() by Sasha Levin fuzzing with trinity. The call site try_to_unmap_cluster() does not lock the pages other than its check_page parameter (which is already locked).

The BUG_ON in mlock_vma_page() is not documented and its purpose is somewhat unclear, but apparently it serializes against page migration, which could otherwise fail to transfer the PG_mlocked flag. This would not be fatal, as the page would be eventually encountered again, but NR_MLOCK accounting would become distorted nevertheless. This patch adds a comment to the BUG_ON in mlock_vma_page() and munlock_vma_page() to that effect.

The call site try_to_unmap_cluster() is fixed so that for page != check_page, trylock_page() is attempted (to avoid possible deadlocks as we already have check_page locked) and mlock_vma_page() is performed only upon success. If the page lock cannot be obtained, the page is left without PG_mlocked, which is again not a problem in the whole unevictable memory design.

---
 mm/mlock.c |    2 ++
 mm/rmap.c  |   14 ++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

@@ -78,6 +78,7 @@ void __clear_page_mlock(struct page *pag
  */
 void mlock_vma_page(struct page *page)
 {
+	/* Serialize with page migration */
 	BUG_ON(!PageLocked(page));
 
 	if (!TestSetPageMlocked(page)) {

@@ -105,6 +106,7 @@ void mlock_vma_page(struct page *page)
  */
 void munlock_vma_page(struct page *page)
 {
+	/* For try_to_munlock() and to serialize with page migration */
 	BUG_ON(!PageLocked(page));
 
 	if (TestClearPageMlocked(page)) {

@@ -1449,9 +1449,19 @@ static int try_to_unmap_cluster(unsigned
 		BUG_ON(!page || PageAnon(page));
 
 		if (locked_vma) {
-			mlock_vma_page(page);   /* no-op if already mlocked */
-			if (page == check_page)
+			if (page == check_page) {
+				/* we know we have check_page locked */
+				mlock_vma_page(page);
 				ret = SWAP_MLOCK;
+			} else if (trylock_page(page)) {
+				/*
+				 * If we can lock the page, perform mlock.
+				 * Otherwise leave the page alone, it will be
+				 * eventually encountered again later.
+				 */
+				mlock_vma_page(page);
+				unlock_page(page);
+			}
 			continue;	/* don't unmap */
 		}
 

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Gao feng <[email protected]>

commit 33d99113b1102c2d2f8603b9ba72d89d915c13f5 upstream.

commit 25fb6ca4ed9cad72f14f61629b68dc03c0d9713f
"net IPv6 : Fix broken IPv6 routing table after loopback down-up" allocates addrconf router for ipv6 address when lo device up. but commit a881ae1f625c599b460cc8f8a7fcb1c438f699ad "ipv6:don't call addrconf_dst_alloc again when enable lo" breaks this behavior.

Since the addrconf router is moved to the garbage list when lo device down, we should release this router and rellocate a new one for ipv6 address when lo device up.

This patch solves bug 67951 on bugzilla
https://bugzilla.kernel.org/show_bug.cgi?id=67951

change from v1:
use ip6_rt_put to repleace ip6_del_rt, thanks Hannes! change code style, suggested by Sergei.

---
 net/ipv6/addrconf.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

@@ -2438,8 +2438,18 @@ static void init_loopback(struct net_dev
 			if (sp_ifa->flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE))
 				continue;
 
-			if (sp_ifa->rt)
-				continue;
+			if (sp_ifa->rt) {
+				/* This dst has been added to garbage list when
+				 * lo device down, release this obsolete dst and
+				 * reallocate a new router for ifa.
+				 */
+				if (sp_ifa->rt->dst.obsolete > 0) {
+					dst_release(sp_ifa->rt);
+					sp_ifa->rt = NULL;
+				} else {
+					continue;
+				}
+			}
 
 			sp_rt = addrconf_dst_alloc(idev, &sp_ifa->addr, 0);
 

Hi,

This patch get a compile warn.
I'll resend one.

Thanks

Compiled and booted on my test system. No dmesg regressions compared to previous 3.4.101

-- Shuah

Shuah Khan
Senior Linux Kernel Developer - Open Source Group
Samsung Research America(Silicon Valley)
[email protected] | (970) 672-0658

Build results:

	total: 119 pass: 113 fail: 6
Failed builds:
	alpha:allmodconfig
	arm:s5pv210_defconfig
	score:defconfig
	sparc64:allmodconfig
	unicore32:defconfig
	xtensa:allmodconfig

Qemu tests all passed.

Results are as expected.

Details are available at http://server.roeck-us.net:8010/builders.

Guenter