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| author | Satoshi Oshima <soshima@redhat.com> | 2006-05-20 15:00:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-05-21 12:59:21 -0700 |
| commit | dc49e3445aa703eb7fd33c7ddb7e4a7bbcf06d30 (patch) | |
| tree | eb164ad61b92f2df2ffab9628adffe06e635c8e2 | |
| parent | be0d03f1c3d3612fe2b6aa451ae87a89382c9231 (diff) | |
| download | linux-dc49e3445aa703eb7fd33c7ddb7e4a7bbcf06d30.tar.gz linux-dc49e3445aa703eb7fd33c7ddb7e4a7bbcf06d30.tar.bz2 linux-dc49e3445aa703eb7fd33c7ddb7e4a7bbcf06d30.zip | |
[PATCH] kprobes: bad manipulation of 2 byte opcode on x86_64
Problem:
If we put a probe onto a callq instruction and the probe is executed,
kernel panic of Bad RIP value occurs.
Root cause:
If resume_execution() found 0xff at first byte of p->ainsn.insn, it must
check the _second_ byte. But current resume_execution check _first_ byte
again.
I changed it checks second byte of p->ainsn.insn.
Kprobes on i386 don't have this problem, because the implementation is a
little bit different from x86_64.
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Satoshi Oshima <soshima@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/x86_64/kernel/kprobes.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c index 1eaa5dae6174..fa1d19ca700a 100644 --- a/arch/x86_64/kernel/kprobes.c +++ b/arch/x86_64/kernel/kprobes.c @@ -514,13 +514,13 @@ static void __kprobes resume_execution(struct kprobe *p, *tos = orig_rip + (*tos - copy_rip); break; case 0xff: - if ((*insn & 0x30) == 0x10) { + if ((insn[1] & 0x30) == 0x10) { /* call absolute, indirect */ /* Fix return addr; rip is correct. */ next_rip = regs->rip; *tos = orig_rip + (*tos - copy_rip); - } else if (((*insn & 0x31) == 0x20) || /* jmp near, absolute indirect */ - ((*insn & 0x31) == 0x21)) { /* jmp far, absolute indirect */ + } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */ + ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */ /* rip is correct. */ next_rip = regs->rip; } |