public inbox for systemtap@sourceware.org
 help / color / mirror / Atom feed
* [PATCH] kprobe: fix resume execution on i386
@ 2006-04-26  7:51 Masami Hiramatsu
  0 siblings, 0 replies; 2+ messages in thread
From: Masami Hiramatsu @ 2006-04-26  7:51 UTC (permalink / raw)
  To: Andrew Morton, Ananth N Mavinakayanahalli, Keshavamurthy, Anil S,
	Prasanna S Panchamukhi
  Cc: SystemTAP, linux-kernel, Jim Keniston, Yumiko Sugita,
	Satoshi Oshima, Hideo Aoki

Hi, Andrew

Here is a patch to fix resume_execution() to handle
iret and absolute jump opcode correctly on i386.
This patch can be applied against 2.6.17-rc2.

Best regards,
-- 
Masami HIRAMATSU
2nd Research Dept.
Hitachi, Ltd., Systems Development Laboratory
E-mail: hiramatu@sdl.hitachi.co.jp

Signed-off-by: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
 kprobes.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)
diff -Narup a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
--- a/arch/i386/kernel/kprobes.c	2006-04-21 12:23:45.000000000 +0900
+++ b/arch/i386/kernel/kprobes.c	2006-04-21 21:26:51.000000000 +0900
@@ -452,10 +452,11 @@ static void __kprobes resume_execution(s
 		*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;
@@ -463,10 +464,13 @@ static void __kprobes resume_execution(s
 	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
 			 */



^ permalink raw reply	[flat|nested] 2+ messages in thread

* [PATCH] kprobe: fix resume execution on i386
@ 2006-04-12 10:10 Masami Hiramatsu
  0 siblings, 0 replies; 2+ messages in thread
From: Masami Hiramatsu @ 2006-04-12 10:10 UTC (permalink / raw)
  To: Ananth N Mavinakayanahalli, Keshavamurthy, Anil S, SystemTAP,
	Prasanna S Panchamukhi
  Cc: Satoshi Oshima, Yumiko Sugita, Hideo Aoki

Hi,

Here is a patch to fix resume_execution() to handle
iret and absolute jump opcode correctly on i386.

As far as I can see, the resume_execution() still can't
handle some prefixes correctly, can it?

Best regards,

-- 
Masami HIRAMATSU
2nd Research Dept.
Hitachi, Ltd., Systems Development Laboratory
E-mail: hiramatu@sdl.hitachi.co.jp


 kprobes.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
diff -Narup a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
--- a/arch/i386/kernel/kprobes.c	2006-04-03 18:30:59.000000000 +0900
+++ b/arch/i386/kernel/kprobes.c	2006-04-05 16:07:47.000000000 +0900
@@ -452,10 +452,11 @@ static void __kprobes resume_execution(s
 		*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;
@@ -463,10 +464,13 @@ static void __kprobes resume_execution(s
 	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
 			 */


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2006-04-26  7:51 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-04-26  7:51 [PATCH] kprobe: fix resume execution on i386 Masami Hiramatsu
  -- strict thread matches above, loose matches on Subject: below --
2006-04-12 10:10 Masami Hiramatsu

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).