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Commit bcff5cd6 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Linus Torvalds
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[PATCH] kprobe: fix resume execution on i386 



Fix resume_execution() to handle iret and absolute jump opcode correctly on
i386.

Signed-off-by: default avatarMasami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Yumiko Sugita <sugita@sdl.hitachi.co.jp>
Cc: Satoshi Oshima <soshima@redhat.com>
Cc: Hideo Aoki <haoki@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bf661987

arch/i386/kernel/kprobes.c

+8 −4
Original line number Diff line number Diff line
@@ -443,10 +443,11 @@ static void __kprobes resume_execution(struct kprobe *p, 
		*tos &= ~(TF_MASK | IF_MASK);

		*tos |= kcb->kprobe_old_eflags;

		break;

	case 0xc3:		/* ret/lret */

	case 0xcb:

	case 0xc2:

	case 0xc2:		/* iret/ret/lret */

	case 0xc3:

	case 0xca:

	case 0xcb:

	case 0xcf:

	case 0xea:		/* jmp absolute -- eip is correct */

		/* eip is already adjusted, no more changes required */

		p->ainsn.boostable = 1;
@@ -454,10 +455,13 @@ static void __kprobes resume_execution(struct kprobe *p, 
	case 0xe8:		/* call relative - Fix return addr */

		*tos = orig_eip + (*tos - copy_eip);

		break;

	case 0x9a:		/* call absolute -- same as call absolute, indirect */

		*tos = orig_eip + (*tos - copy_eip);

		goto no_change;

	case 0xff:

		if ((p->ainsn.insn[1] & 0x30) == 0x10) {

			/* call absolute, indirect */

			/*

			 * call absolute, indirect

			 * Fix return addr; eip is correct.

			 * But this is not boostable

			 */