Messages in this thread | | | Subject | Re: [PATCH 1/2] i386: Disallow kprobes on NMI handlers | From | Fernando Luis Vázquez Cao <> | Date | Thu, 10 Aug 2006 19:40:55 +0900 |
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This version of the patch does not compile. I will fix this problem and resend it. Sorry for the noise.
On Thu, 2006-08-10 at 19:36 +0900, Fernando Luis Vázquez Cao wrote: > A kprobe executes IRET early and that could cause NMI recursion and stack > corruption. > > Note: This problem was originally identified and solved by Andi Kleen in the > x86_64 architecture. This patch is an adaption of his patch for i386. > > Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp> > --- > > diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/entry.S linux-2.6.18-rc4/arch/i386/kernel/entry.S > --- linux-2.6.18-rc4-orig/arch/i386/kernel/entry.S 2006-08-10 17:24:14.000000000 +0900 > +++ linux-2.6.18-rc4/arch/i386/kernel/entry.S 2006-08-10 17:31:55.000000000 +0900 > @@ -725,7 +725,7 @@ debug_stack_correct: > * check whether we got an NMI on the debug path where the debug > * fault happened on the sysenter path. > */ > -ENTRY(nmi) > +KPROBE_ENTRY(nmi) > RING0_INT_FRAME > pushl %eax > CFI_ADJUST_CFA_OFFSET 4 > diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/nmi.c linux-2.6.18-rc4/arch/i386/kernel/nmi.c > --- linux-2.6.18-rc4-orig/arch/i386/kernel/nmi.c 2006-08-10 17:24:15.000000000 +0900 > +++ linux-2.6.18-rc4/arch/i386/kernel/nmi.c 2006-08-10 17:40:22.000000000 +0900 > @@ -579,7 +579,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog); > > extern void die_nmi(struct pt_regs *, const char *msg); > > -void nmi_watchdog_tick (struct pt_regs * regs) > +void __kprobes nmi_watchdog_tick (struct pt_regs * regs) > { > > /* > diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/traps.c linux-2.6.18-rc4/arch/i386/kernel/traps.c > --- linux-2.6.18-rc4-orig/arch/i386/kernel/traps.c 2006-08-10 17:24:16.000000000 +0900 > +++ linux-2.6.18-rc4/arch/i386/kernel/traps.c 2006-08-10 18:16:12.000000000 +0900 > @@ -626,7 +626,8 @@ 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. Dazed and confused, but trying " > "to continue\n"); > @@ -637,7 +638,8 @@ static void mem_parity_error(unsigned ch > 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; > > @@ -653,7 +655,8 @@ static void io_check_error(unsigned char > 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 > @@ -671,7 +674,7 @@ static void unknown_nmi_error(unsigned c > > 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) > @@ -703,7 +706,7 @@ void die_nmi (struct pt_regs *regs, cons > 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; > > @@ -741,14 +744,14 @@ static void default_do_nmi(struct pt_reg > reassert_nmi(); > } > > -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; > > -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; > > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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