diff options
| author | Prasanna S Panchamukhi | 2005-05-05 16:15:40 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2005-05-05 16:36:39 -0700 |
| commit | 0b9e2cac8a56e197d0a9e06268db4c8652d23dd5 (patch) | |
| tree | 6bab2badad512d39c2b606e8c2c12d271c1bee35 /arch | |
| parent | 3a0a64e6c917b2ccc311cf978cc9d7eef7b31c47 (diff) | |
[PATCH] Kprobes: Incorrect handling of probes on ret/lret instruction
Kprobes could not handle the insertion of a probe on the ret/lret
instruction and used to oops after single stepping since kprobes was
modifying eip/rip incorrectly. Adjustment of eip/rip is not required after
single stepping in case of ret/lret instruction, because eip/rip points to
the correct location after execution of the ret/lret instruction. This
patch fixes the above problem.
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 7 | ||||
| -rw-r--r-- | arch/x86_64/kernel/kprobes.c | 7 |
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index 671681659243..59ff9b455069 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -217,6 +217,13 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs) *tos &= ~(TF_MASK | IF_MASK); *tos |= kprobe_old_eflags; break; + case 0xc3: /* ret/lret */ + case 0xcb: + case 0xc2: + case 0xca: + regs->eflags &= ~TF_MASK; + /* eip is already adjusted, no more changes required*/ + return; case 0xe8: /* call relative - Fix return addr */ *tos = orig_eip + (*tos - copy_eip); break; diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c index 4f2a852299b6..f77f8a0ff187 100644 --- a/arch/x86_64/kernel/kprobes.c +++ b/arch/x86_64/kernel/kprobes.c @@ -355,6 +355,13 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs) *tos &= ~(TF_MASK | IF_MASK); *tos |= kprobe_old_rflags; break; + case 0xc3: /* ret/lret */ + case 0xcb: + case 0xc2: + case 0xca: + regs->eflags &= ~TF_MASK; + /* rip is already adjusted, no more changes required*/ + return; case 0xe8: /* call relative - Fix return addr */ *tos = orig_rip + (*tos - copy_rip); break; |