The patch titled
Fix potential interrupts during alternative patching
has been added to the -mm tree. Its filename is
fix-potential-interrupts-during-alternative-patching-was.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Fix potential interrupts during alternative patching
From: Zachary Amsden <zach@xxxxxxxxxx>
Interrupts must be disabled during alternative instruction patching. On
systems with high timer IRQ rates, or when running in an emulator, timing
differences can result in random kernel panics because of running partially
patched instructions. This doesn't yet fix NMIs, which requires extricating
the patch code from the late bug checking and is logically separate (and also
less likely to cause problems).
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/i386/kernel/alternative.c | 4 ++++
1 file changed, 4 insertions(+)
diff -puN arch/i386/kernel/alternative.c~fix-potential-interrupts-during-alternative-patching-was arch/i386/kernel/alternative.c
--- a/arch/i386/kernel/alternative.c~fix-potential-interrupts-during-alternative-patching-was
+++ a/arch/i386/kernel/alternative.c
@@ -344,6 +344,7 @@ void alternatives_smp_switch(int smp)
void __init alternative_instructions(void)
{
+ unsigned long flags;
if (no_replacement) {
printk(KERN_INFO "(SMP-)alternatives turned off\n");
free_init_pages("SMP alternatives",
@@ -351,6 +352,8 @@ void __init alternative_instructions(voi
(unsigned long)__smp_alt_end);
return;
}
+
+ local_irq_save(flags);
apply_alternatives(__alt_instructions, __alt_instructions_end);
/* switch to patch-once-at-boottime-only mode and free the
@@ -386,4 +389,5 @@ void __init alternative_instructions(voi
alternatives_smp_switch(0);
}
#endif
+ local_irq_restore(flags);
}
_
Patches currently in -mm which might be from zach@xxxxxxxxxx are
fix-potential-interrupts-during-alternative-patching-was.patch
i386-pda-basic-definitions-for-i386-pda.patch
i386-pda-initialize-the-per-cpu-data-area.patch
i386-pda-use-%gs-as-the-pda-base-segment-in-the-kernel.patch
i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi.patch
i386-pda-update-sys_vm86-to-cope-with-changed-pt_regs-and-%gs-usage.patch
i386-pda-implement-smp_processor_id-with-the-pda.patch
i386-pda-implement-current-with-the-pda.patch
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