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authorMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>2014-04-17 17:17:40 +0900
committerIngo Molnar <mingo@kernel.org>2014-04-24 10:03:00 +0200
commitecd50f714c421c759354632dd00f70c718c95b10 (patch)
tree82fc08180816ee1eb79e92a9060af1a25d1dd802 /arch/x86/kernel/traps.c
parentkprobes/x86: Call exception handlers directly from do_int3/do_debug (diff)
downloadlinux-dev-ecd50f714c421c759354632dd00f70c718c95b10.tar.xz
linux-dev-ecd50f714c421c759354632dd00f70c718c95b10.zip
kprobes, x86: Call exception_enter after kprobes handled
Move exception_enter() call after kprobes handler is done. Since the exception_enter() involves many other functions (like printk), it can cause recursive int3/break loop when kprobes probe such functions. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Kees Cook <keescook@chromium.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081740.26341.10894.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/traps.c')
-rw-r--r--arch/x86/kernel/traps.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index e5d4a70814d7..ba9abe9cbce3 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -327,7 +327,6 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
if (poke_int3_handler(regs))
return;
- prev_state = exception_enter();
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
SIGTRAP) == NOTIFY_STOP)
@@ -338,6 +337,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
if (kprobe_int3_handler(regs))
return;
#endif
+ prev_state = exception_enter();
if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
SIGTRAP) == NOTIFY_STOP)
@@ -415,8 +415,6 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
unsigned long dr6;
int si_code;
- prev_state = exception_enter();
-
get_debugreg(dr6, 6);
/* Filter out all the reserved bits which are preset to 1 */
@@ -449,6 +447,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
if (kprobe_debug_handler(regs))
goto exit;
#endif
+ prev_state = exception_enter();
if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code,
SIGTRAP) == NOTIFY_STOP)