From: Andi Kleen Date: Fri, 3 Feb 2006 20:50:41 +0000 (+0100) Subject: [PATCH] x86_64: Disallow kprobes on NMI handlers X-Git-Tag: v2.6.16-rc3~202 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eddb6fb9a54cdc8c7c37e056a2b4bbbc8a128a36;p=linux-2.6 [PATCH] x86_64: Disallow kprobes on NMI handlers A kprobe executes IRET early and that could cause NMI recursion and stack corruption. Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index dbdba56e8f..cdf9cb1288 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S @@ -922,7 +922,7 @@ KPROBE_ENTRY(debug) .previous .text /* runs on exception stack */ -ENTRY(nmi) +KPROBE_ENTRY(nmi) INTR_FRAME pushq $-1 CFI_ADJUST_CFA_OFFSET 8 @@ -969,6 +969,7 @@ paranoid_schedule: cli jmp paranoid_userspace CFI_ENDPROC + .previous .text KPROBE_ENTRY(int3) INTR_FRAME diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index 5fae6f0cd9..8be407a1f6 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -468,7 +469,7 @@ void touch_nmi_watchdog (void) touch_softlockup_watchdog(); } -void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason) +void __kprobes nmi_watchdog_tick(struct pt_regs * regs, unsigned reason) { int sum; int touched = 0; @@ -512,14 +513,14 @@ void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason) } } -static int dummy_nmi_callback(struct pt_regs * regs, int cpu) +static __kprobes int dummy_nmi_callback(struct pt_regs * regs, int cpu) { return 0; } static nmi_callback_t nmi_callback = dummy_nmi_callback; -asmlinkage void do_nmi(struct pt_regs * regs, long error_code) +asmlinkage __kprobes void do_nmi(struct pt_regs * regs, long error_code) { int cpu = safe_smp_processor_id(); diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index 8bb0aeda78..ee1b2da9e5 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -372,7 +372,7 @@ void out_of_line_bug(void) static DEFINE_SPINLOCK(die_lock); static int die_owner = -1; -unsigned long oops_begin(void) +unsigned __kprobes long oops_begin(void) { int cpu = safe_smp_processor_id(); unsigned long flags; @@ -391,7 +391,7 @@ unsigned long oops_begin(void) return flags; } -void oops_end(unsigned long flags) +void __kprobes oops_end(unsigned long flags) { die_owner = -1; bust_spinlocks(0); @@ -400,7 +400,7 @@ void oops_end(unsigned long flags) panic("Oops"); } -void __die(const char * str, struct pt_regs * regs, long err) +void __kprobes __die(const char * str, struct pt_regs * regs, long err) { static int die_counter; printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter); @@ -432,7 +432,7 @@ void die(const char * str, struct pt_regs * regs, long err) do_exit(SIGSEGV); } -void die_nmi(char *str, struct pt_regs *regs) +void __kprobes die_nmi(char *str, struct pt_regs *regs) { unsigned long flags = oops_begin(); @@ -575,7 +575,8 @@ asmlinkage void __kprobes do_general_protection(struct pt_regs * regs, } } -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("Uhhuh. NMI received. Dazed and confused, but trying to continue\n"); printk("You probably have a hardware problem with your RAM chips\n"); @@ -585,7 +586,8 @@ static void mem_parity_error(unsigned char reason, struct pt_regs * regs) outb(reason, 0x61); } -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) { printk("NMI: IOCK error (debug interrupt?)\n"); show_registers(regs); @@ -598,7 +600,8 @@ 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) { printk("Uhhuh. NMI received for unknown reason %02x.\n", reason); printk("Dazed and confused, but trying to continue\n"); printk("Do you have a strange power saving mode enabled?\n"); @@ -606,7 +609,7 @@ static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) /* Runs on IST stack. This code must keep interrupts off all the time. Nested NMIs are prevented by the CPU. */ -asmlinkage void default_do_nmi(struct pt_regs *regs) +asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs) { unsigned char reason = 0; int cpu; @@ -658,7 +661,7 @@ asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code) /* Help handler running on IST stack to switch back to user stack for scheduling or signal handling. The actual stack switch is done in entry.S */ -asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs) +asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */