Messages in this thread Patch in this message |  | | Subject | [PATCH -tip v4 3/6] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* | From | Masami Hiramatsu <> | Date | Wed, 04 Dec 2013 01:28:49 +0000 |
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Prohibit probing on debug_stack_reset and debug_stack_set_zero. Since the both functions are called from TRACE_IRQS_ON/OFF_DEBUG macros which run in int3 ist entry, probing it may cause a soft lockup.
This happens when the kernel built with CONFIG_DYNAMIC_FTRACE=y and CONFIG_TRACE_IRQFLAGS=y.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> --- arch/x86/kernel/cpu/common.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 6abc172..220de22 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -8,6 +8,7 @@ #include <linux/delay.h> #include <linux/sched.h> #include <linux/init.h> +#include <linux/kprobes.h> #include <linux/kgdb.h> #include <linux/smp.h> #include <linux/io.h> @@ -1153,6 +1154,7 @@ int is_debug_stack(unsigned long addr) (addr <= __get_cpu_var(debug_stack_addr) && addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ)); } +NOKPROBE_SYMBOL(is_debug_stack); DEFINE_PER_CPU(u32, debug_idt_ctr); @@ -1161,6 +1163,7 @@ void debug_stack_set_zero(void) this_cpu_inc(debug_idt_ctr); load_current_idt(); } +NOKPROBE_SYMBOL(debug_stack_set_zero); void debug_stack_reset(void) { @@ -1169,6 +1172,7 @@ void debug_stack_reset(void) if (this_cpu_dec_return(debug_idt_ctr) == 0) load_current_idt(); } +NOKPROBE_SYMBOL(debug_stack_reset); #else /* CONFIG_X86_64 */
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