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x86 updates for 2.6.22-stable

PATCH New Andi Kleen 1 participant 6 messages Aug 15, 2007

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Andi Kleen

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#0 lore raw

cover x86 updates for 2.6.22-stable

Should all go into the next stable release.

Two of the patches (cfi probe and rept fix) are only pending for mainline (I hope Linus applies them today). They should not go in before hitting mainline.

-Andi

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#1 lore raw

PATCH 1/5 i386: allow debuggers to access the vsyscall page with compat vDSO

From: "Jan Beulich" <[email protected]>

Signed-off-by Jan Beulich <[email protected]>
Signed-off-by Andi Kleen <[email protected]>
 arch/i386/kernel/sysenter.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
arch/i386/kernel/sysenter.c +3 -1
Index: linux-2.6.22-stable/arch/i386/kernel/sysenter.c
===================================================================
@@ -336,7 +336,9 @@ struct vm_area_struct *get_gate_vma(stru
 
 int in_gate_area(struct task_struct *task, unsigned long addr)
 {
-	return 0;
+	const struct vm_area_struct *vma = get_gate_vma(task);
+
+	return vma && addr >= vma->vm_start && addr < vma->vm_end;
 }
 
 int in_gate_area_no_task(unsigned long addr)
author
#2 lore raw

PATCH 2/5 x86_64: Check for .cfi_rel_offset in CFI probe

In reply to Andi Kleen

Very old binutils have .cfi_startproc/endproc, but no .cfi_rel_offset. Check for .cfi_rel_offset too.

Cc [email protected]
---
 arch/i386/Makefile   |    4 ++--
 arch/x86_64/Makefile |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)
arch/x86_64/Makefile +2 -2
Index: linux-2.6.22-stable/arch/x86_64/Makefile
===================================================================
@@ -57,8 +57,8 @@ cflags-y += $(call cc-option,-mno-sse -m
 cflags-y += -maccumulate-outgoing-args
 
 # do binutils support CFI?
-cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
-AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+cflags-y += $(call as-instr,.cfi_startproc\n.cfi_rel_offset rsp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_rel_offset rsp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 
 # is .cfi_signal_frame supported too?
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
arch/i386/Makefile +2 -2
Index: linux-2.6.22-stable/arch/i386/Makefile
===================================================================
@@ -51,8 +51,8 @@ cflags-y += -maccumulate-outgoing-args
 CFLAGS				+= $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;)
 
 # do binutils support CFI?
-cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
-AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+cflags-y += $(call as-instr,.cfi_startproc\n.cfi_rel_offset esp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_rel_offset esp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 
 # is .cfi_signal_frame supported too?
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
author
#3 lore raw

PATCH 3/5 x86_64: Change PMDS invocation to single macro

In reply to Andi Kleen

Very old binutils (2.12.90...) seem to have trouble with newlines in assembler macro invocation. They put them into the resulting argument expansion. In this case this lead to a parse error because a .rept expression ended up spread over multiple lines. Change the PMDS() invocation to a single line.

Signed-off-by Andi Kleen <[email protected]>
---
 arch/x86_64/kernel/head.S |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
arch/x86_64/kernel/head.S +1 -2
Index: linux-2.6.22-stable/arch/x86_64/kernel/head.S
===================================================================
@@ -326,8 +326,7 @@ NEXT_PAGE(level2_kernel_pgt)
 	/* 40MB kernel mapping. The kernel code cannot be bigger than that.
 	   When you change this change KERNEL_TEXT_SIZE in page.h too. */
 	/* (2^48-(2*1024*1024*1024)-((2^39)*511)-((2^30)*510)) = 0 */
-	PMDS(0x0000000000000000, __PAGE_KERNEL_LARGE_EXEC|_PAGE_GLOBAL,
-		KERNEL_TEXT_SIZE/PMD_SIZE)
+	PMDS(0x0000000000000000, __PAGE_KERNEL_LARGE_EXEC|_PAGE_GLOBAL, KERNEL_TEXT_SIZE/PMD_SIZE)
 	/* Module mapping starts here */
 	.fill	(PTRS_PER_PMD - (KERNEL_TEXT_SIZE/PMD_SIZE)),8,0
author
#4 lore raw

PATCH 4/5 i386: Fix double fault handler

In reply to Andi Kleen

From: Chuck Ebbert <[email protected]>

The new percpu code has apparently broken the doublefault handler when CONFIG_DEBUG_SPINLOCK is set. Doublefault is handled by a hardware task, making the check

        SPIN_BUG_ON(lock->owner == current, lock, "recursion");

fault because it uses the FS register to access the percpu data for current, and that register is zero in the new TSS. (The trace I saw was on 2.6.20 where it was GS, but it looks like this will still happen with FS on 2.6.22.)

Initializing FS in the doublefault_tss should fix it.

AK: Also fix broken ptr_ok() and turn printks into KERN_EMERG
AK: And add a PANIC prefix to make clear the system will hang
AK: (e.g. x86-64 will recover)

Signed-off-by Chuck Ebbert <[email protected]>
Signed-off-by Andi Kleen <[email protected]>
 arch/i386/kernel/doublefault.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)
arch/i386/kernel/doublefault.c +7 -6
Index: linux-2.6.22-stable/arch/i386/kernel/doublefault.c
===================================================================
@@ -13,7 +13,7 @@
 static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
 #define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
 
-#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + 0x1000000)
+#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM)
 
 static void doublefault_fn(void)
 {

@@ -23,23 +23,23 @@ static void doublefault_fn(void)
 	store_gdt(&gdt_desc);
 	gdt = gdt_desc.address;
 
-	printk("double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
+	printk(KERN_EMERG "PANIC: double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
 
 	if (ptr_ok(gdt)) {
 		gdt += GDT_ENTRY_TSS << 3;
 		tss = *(u16 *)(gdt+2);
 		tss += *(u8 *)(gdt+4) << 16;
 		tss += *(u8 *)(gdt+7) << 24;
-		printk("double fault, tss at %08lx\n", tss);
+		printk(KERN_EMERG "double fault, tss at %08lx\n", tss);
 
 		if (ptr_ok(tss)) {
 			struct i386_hw_tss *t = (struct i386_hw_tss *)tss;
 
-			printk("eip = %08lx, esp = %08lx\n", t->eip, t->esp);
+			printk(KERN_EMERG "eip = %08lx, esp = %08lx\n", t->eip, t->esp);
 
-			printk("eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
+			printk(KERN_EMERG "eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
 				t->eax, t->ebx, t->ecx, t->edx);
-			printk("esi = %08lx, edi = %08lx\n",
+			printk(KERN_EMERG "esi = %08lx, edi = %08lx\n",
 				t->esi, t->edi);
 		}
 	}

@@ -63,6 +63,7 @@ struct tss_struct doublefault_tss __cach
 		.cs		= __KERNEL_CS,
 		.ss		= __KERNEL_DS,
 		.ds		= __USER_DS,
+		.fs		= __KERNEL_PERCPU,
 
 		.__cr3		= __pa(swapper_pg_dir)
 	}
author
#5 lore raw

PATCH 5/5 i386: Handle P6s without performance counters in nmi watchdog

In reply to Andi Kleen

I got an oops while booting a 32bit kernel on KVM because it doesn't implement performance counters used by the NMI watchdog. Handle this case.

Cc [email protected]
Signed-off-by Andi Kleen <[email protected]>
---
 arch/i386/kernel/cpu/perfctr-watchdog.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
arch/i386/kernel/cpu/perfctr-watchdog.c +3 -1
Index: linux-2.6.22-stable/arch/i386/kernel/cpu/perfctr-watchdog.c
===================================================================
@@ -346,7 +346,9 @@ static int setup_p6_watchdog(unsigned nm
 	perfctr_msr = MSR_P6_PERFCTR0;
 	evntsel_msr = MSR_P6_EVNTSEL0;
 
-	wrmsrl(perfctr_msr, 0UL);
+	/* KVM doesn't implement this MSR */
+	if (wrmsr_safe(perfctr_msr, 0, 0) < 0)
+		return 0;
 
 	evntsel = P6_EVNTSEL_INT
 		| P6_EVNTSEL_OS