diff options
| author | Bodo Stroesser <bstroesser@fujitsu-siemens.com> | 2005-09-03 15:57:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 00:06:20 -0700 |
| commit | ab1c23c24471c760c573f4fb0dd78e166ddfd844 (patch) | |
| tree | fad0953ece8710b58a14a2a9eed1b1f83fb47f4b /arch | |
| parent | 1b38f0064e4e0b9ec626e39f0740b1cf2e295743 (diff) | |
[PATCH] SYSEMU: fix sysaudit / singlestep interaction
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
This is simply an adjustment for "Ptrace - i386: fix Syscall Audit interaction
with singlestep" to work on top of SYSEMU patches, too. On this patch, I have
some doubts: I wonder why we need to alter that way ptrace_disable().
I left the patch this way because it has been extensively tested, but I don't
understand the reason.
The current PTRACE_DETACH handling simply clears child->ptrace; actually this
is not enough because entry.S just looks at the thread_flags; actually,
do_syscall_trace checks current->ptrace but I don't think depending on that is
good, at least for performance, so I think the clearing is done elsewhere.
For instance, on PTRACE_CONT it's done, but doing PTRACE_DETACH without
PTRACE_CONT is possible (and happens when gdb crashes and one kills it
manually).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Roland McGrath <roland@redhat.com>
Cc: Jeff Dike <jdike@addtoit.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/ptrace.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c index 3196ba50fcd..340980203b0 100644 --- a/arch/i386/kernel/ptrace.c +++ b/arch/i386/kernel/ptrace.c @@ -271,6 +271,8 @@ static void clear_singlestep(struct task_struct *child) void ptrace_disable(struct task_struct *child) { clear_singlestep(child); + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); } /* @@ -693,14 +695,29 @@ __attribute__((regparm(3))) int do_syscall_trace(struct pt_regs *regs, int entryexit) { int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU), ret = 0; - /* With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP */ + /* With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall + * interception. */ int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP); /* do the secure computing check first */ secure_computing(regs->orig_eax); - if (unlikely(current->audit_context) && entryexit) - audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax); + if (unlikely(current->audit_context)) { + if (entryexit) + audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax); + /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only + * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is + * not used, entry.S will call us only on syscall exit, not + * entry; so when TIF_SYSCALL_AUDIT is used we must avoid + * calling send_sigtrap() on syscall entry. + * + * Note that when PTRACE_SYSEMU_SINGLESTEP is used, + * is_singlestep is false, despite his name, so we will still do + * the correct thing. + */ + else if (is_singlestep) + goto out; + } if (!(current->ptrace & PT_PTRACED)) goto out; |