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Commit 98def1de authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
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kprobes, x86: Prohibit probing on thunk functions and restore 



thunk/restore functions are also used for tracing irqoff etc.
and those are involved in kprobe's exception handling.
Prohibit probing on them to avoid kernel crash.

Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140417081726.26341.3872.stgit@ltc230.yrl.intra.hitachi.co.jp


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 80271972

arch/x86/lib/thunk_32.S

+2 −1
Original line number Diff line number Diff line
@@ -4,8 +4,8 @@ 
 *  (inspired by Andi Kleen's thunk_64.S)

 * Subject to the GNU public license, v.2. No warranty of any kind.

 */



	#include <linux/linkage.h>

	#include <asm/asm.h>



#ifdef CONFIG_TRACE_IRQFLAGS

	/* put return address in eax (arg1) */
@@ -22,6 +22,7 @@ 
	popl %ecx

	popl %eax

	ret

	_ASM_NOKPROBE(\name)

	.endm



	thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller

arch/x86/lib/thunk_64.S

+3 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/linkage.h>

#include <asm/dwarf2.h>

#include <asm/calling.h>

#include <asm/asm.h>



	/* rdi:	arg1 ... normal C conventions. rax is saved/restored. */

	.macro THUNK name, func, put_ret_addr_in_rdi=0
@@ -25,6 +26,7 @@ 
	call \func

	jmp  restore

	CFI_ENDPROC

	_ASM_NOKPROBE(\name)

	.endm



#ifdef CONFIG_TRACE_IRQFLAGS
@@ -43,3 +45,4 @@ restore: 
	RESTORE_ARGS

	ret

	CFI_ENDPROC

	_ASM_NOKPROBE(restore)