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| author | Fernando Luis Vzquez Cao <fernando@oss.ntt.co.jp> | 2006-09-26 10:52:36 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:36 +0200 |
| commit | 06039754d775d3e48e4a292e4f353321205eff53 (patch) | |
| tree | a6abdd9ca0efb34006792e7275c4a2c954b229be /arch/i386/kernel/traps.c | |
| parent | 6f6b1e0477ccb2f25a9b045e38440347d2ce21c8 (diff) | |
| download | lwn-06039754d775d3e48e4a292e4f353321205eff53.tar.gz lwn-06039754d775d3e48e4a292e4f353321205eff53.zip | |
[PATCH] i386: Disallow kprobes on NMI handlers
A kprobe executes IRET early and that could cause NMI recursion and stack
corruption.
Note: This problem was originally spotted and solved by Andi Kleen in the
x86_64 architecture. This patch is an adaption of his patch for i386.
AK: Merged with current code which was a bit different.
AK: Removed printk in nmi handler that shouldn't be there in the first time
AK: Added missing include.
AK: added KPROBES_END
Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/i386/kernel/traps.c')
| -rw-r--r-- | arch/i386/kernel/traps.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 00d643f3de41..5c0f4960c67d 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -689,7 +689,8 @@ gp_in_kernel: } } -static void mem_parity_error(unsigned char reason, struct pt_regs * regs) +static __kprobes void +mem_parity_error(unsigned char reason, struct pt_regs * regs) { printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x on " "CPU %d.\n", reason, smp_processor_id()); @@ -704,7 +705,8 @@ static void mem_parity_error(unsigned char reason, struct pt_regs * regs) clear_mem_error(reason); } -static void io_check_error(unsigned char reason, struct pt_regs * regs) +static __kprobes void +io_check_error(unsigned char reason, struct pt_regs * regs) { unsigned long i; @@ -720,7 +722,8 @@ static void io_check_error(unsigned char reason, struct pt_regs * regs) outb(reason, 0x61); } -static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) +static __kprobes void +unknown_nmi_error(unsigned char reason, struct pt_regs * regs) { #ifdef CONFIG_MCA /* Might actually be able to figure out what the guilty party @@ -741,7 +744,7 @@ static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) static DEFINE_SPINLOCK(nmi_print_lock); -void die_nmi (struct pt_regs *regs, const char *msg) +void __kprobes die_nmi(struct pt_regs *regs, const char *msg) { if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) == NOTIFY_STOP) @@ -773,7 +776,7 @@ void die_nmi (struct pt_regs *regs, const char *msg) do_exit(SIGSEGV); } -static void default_do_nmi(struct pt_regs * regs) +static __kprobes void default_do_nmi(struct pt_regs * regs) { unsigned char reason = 0; @@ -811,7 +814,7 @@ static void default_do_nmi(struct pt_regs * regs) reassert_nmi(); } -fastcall void do_nmi(struct pt_regs * regs, long error_code) +fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code) { int cpu; |