* [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping
@ 2009-11-12 17:38 Oleg Nesterov
2009-11-13 19:25 ` Andrew Morton
0 siblings, 1 reply; 5+ messages in thread
From: Oleg Nesterov @ 2009-11-12 17:38 UTC (permalink / raw)
To: Andrew Morton
Cc: Benjamin Herrenschmidt, H. Peter Anvin, Ingo Molnar,
Paul Mackerras, Roland McGrath, Srinivasa Ds, Thomas Gleixner,
linux-arch, linux-kernel
Suggested by Roland.
Change tracehook_report_syscall_exit() to look at step flag and send
the trap signal if needed.
This change affects ia64, microblaze, parisc, powerpc, sh. They pass
nonzero "step" argument to tracehook but since it was ignored the tracee
reports via ptrace_notify(), this is not right and not consistent.
- PTRACE_SETSIGINFO doesn't work
- if the tracer resumes the tracee with signr != 0 the new signal
is generated rather than delivering it
- If PT_TRACESYSGOOD is set the tracee reports the wrong exit_code
I don't have a powerpc machine, but I think this test-case should
see the difference:
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <assert.h>
#include <stdio.h>
int main(void)
{
int pid, status;
if (!(pid = fork())) {
assert(ptrace(PTRACE_TRACEME) == 0);
kill(getpid(), SIGSTOP);
getppid();
return 0;
}
assert(pid == wait(&status));
assert(ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACESYSGOOD) == 0);
assert(ptrace(PTRACE_SYSCALL, pid, 0,0) == 0);
assert(pid == wait(&status));
assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0);
assert(pid == wait(&status));
if (status == 0x57F)
return 0;
printf("kernel bug: status=%X shouldn't have 0x80\n", status);
return 1;
}
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
---
include/linux/tracehook.h | 7 +++++++
1 file changed, 7 insertions(+)
--- TH/include/linux/tracehook.h~3_TRACEHOOK_HANDLE_STEPPING 2009-11-10 01:03:22.000000000 +0100
+++ TH/include/linux/tracehook.h 2009-11-10 22:00:37.000000000 +0100
@@ -134,6 +134,13 @@ static inline __must_check int tracehook
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
+ if (step) {
+ siginfo_t info;
+ user_single_step_siginfo(current, regs, &info);
+ force_sig_info(SIGTRAP, &info, current);
+ return;
+ }
+
ptrace_report_syscall(regs);
}
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping
2009-11-12 17:38 [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping Oleg Nesterov
@ 2009-11-13 19:25 ` Andrew Morton
2009-11-13 19:25 ` Andrew Morton
2009-11-13 19:58 ` Oleg Nesterov
0 siblings, 2 replies; 5+ messages in thread
From: Andrew Morton @ 2009-11-13 19:25 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Benjamin Herrenschmidt, H. Peter Anvin, Ingo Molnar,
Paul Mackerras, Roland McGrath, Srinivasa Ds, Thomas Gleixner,
linux-arch, linux-kernel
On Thu, 12 Nov 2009 18:38:53 +0100
Oleg Nesterov <oleg@redhat.com> wrote:
> Change tracehook_report_syscall_exit() to look at step flag and send
> the trap signal if needed.
>
> This change affects ia64, microblaze, parisc, powerpc, sh. They pass
> nonzero "step" argument to tracehook but since it was ignored the tracee
> reports via ptrace_notify(), this is not right and not consistent.
This patch conflicts with utrace-core.patch a bit:
***************
*** 134,139 ****
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
ptrace_report_syscall(regs);
}
--- 140,147 ----
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
+ if (task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_EXIT))
+ utrace_report_syscall_exit(regs);
ptrace_report_syscall(regs);
}
I did this:
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
if (step) {
siginfo_t info;
user_single_step_siginfo(current, regs, &info);
force_sig_info(SIGTRAP, &info, current);
return;
}
+ if (task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_EXIT))
+ utrace_report_syscall_exit(regs);
ptrace_report_syscall(regs);
}
utrace-core.patch is getting rather old. What is its status?
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping
2009-11-13 19:25 ` Andrew Morton
@ 2009-11-13 19:25 ` Andrew Morton
2009-11-13 19:58 ` Oleg Nesterov
1 sibling, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2009-11-13 19:25 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Benjamin Herrenschmidt, H. Peter Anvin, Ingo Molnar,
Paul Mackerras, Roland McGrath, Srinivasa Ds, Thomas Gleixner,
linux-arch, linux-kernel
On Thu, 12 Nov 2009 18:38:53 +0100
Oleg Nesterov <oleg@redhat.com> wrote:
> Change tracehook_report_syscall_exit() to look at step flag and send
> the trap signal if needed.
>
> This change affects ia64, microblaze, parisc, powerpc, sh. They pass
> nonzero "step" argument to tracehook but since it was ignored the tracee
> reports via ptrace_notify(), this is not right and not consistent.
This patch conflicts with utrace-core.patch a bit:
***************
*** 134,139 ****
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
ptrace_report_syscall(regs);
}
--- 140,147 ----
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
+ if (task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_EXIT))
+ utrace_report_syscall_exit(regs);
ptrace_report_syscall(regs);
}
I did this:
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
if (step) {
siginfo_t info;
user_single_step_siginfo(current, regs, &info);
force_sig_info(SIGTRAP, &info, current);
return;
}
+ if (task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_EXIT))
+ utrace_report_syscall_exit(regs);
ptrace_report_syscall(regs);
}
utrace-core.patch is getting rather old. What is its status?
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping
2009-11-13 19:25 ` Andrew Morton
2009-11-13 19:25 ` Andrew Morton
@ 2009-11-13 19:58 ` Oleg Nesterov
2009-11-13 20:15 ` Roland McGrath
1 sibling, 1 reply; 5+ messages in thread
From: Oleg Nesterov @ 2009-11-13 19:58 UTC (permalink / raw)
To: Andrew Morton
Cc: Benjamin Herrenschmidt, H. Peter Anvin, Ingo Molnar,
Paul Mackerras, Roland McGrath, Srinivasa Ds, Thomas Gleixner,
linux-arch, linux-kernel
On 11/13, Andrew Morton wrote:
>
> On Thu, 12 Nov 2009 18:38:53 +0100
> Oleg Nesterov <oleg@redhat.com> wrote:
>
> > Change tracehook_report_syscall_exit() to look at step flag and send
> > the trap signal if needed.
> >
> > This change affects ia64, microblaze, parisc, powerpc, sh. They pass
> > nonzero "step" argument to tracehook but since it was ignored the tracee
> > reports via ptrace_notify(), this is not right and not consistent.
>
> This patch conflicts with utrace-core.patch a bit:
Ah, indeed, sorry...
> static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
> {
> if (step) {
> siginfo_t info;
> user_single_step_siginfo(current, regs, &info);
> force_sig_info(SIGTRAP, &info, current);
> return;
> }
>
> + if (task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_EXIT))
> + utrace_report_syscall_exit(regs);
> ptrace_report_syscall(regs);
> }
>
>
> utrace-core.patch is getting rather old. What is its status?
Roland, given that you are going to send the updated utrace patch,
perhaps it makes sense to drop this old utrace-core.patch from -mm?
Oleg.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping
2009-11-13 19:58 ` Oleg Nesterov
@ 2009-11-13 20:15 ` Roland McGrath
0 siblings, 0 replies; 5+ messages in thread
From: Roland McGrath @ 2009-11-13 20:15 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Benjamin Herrenschmidt, H. Peter Anvin,
Ingo Molnar, Paul Mackerras, Srinivasa Ds, Thomas Gleixner,
linux-arch, linux-kernel
> Roland, given that you are going to send the updated utrace patch,
> perhaps it makes sense to drop this old utrace-core.patch from -mm?
Yes, I think that's the easiest thing to do. When we send new utrace and
ptrace code, we can make that relative to -mm or at least relative to the
all ptrace-related patches you've already submitted in this cycle.
Thanks,
Roland
^ permalink raw reply [flat|nested] 5+ messages in thread
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2009-11-12 17:38 [PATCH v2 3/5] ptrace: change tracehook_report_syscall_exit() to handle stepping Oleg Nesterov
2009-11-13 19:25 ` Andrew Morton
2009-11-13 19:25 ` Andrew Morton
2009-11-13 19:58 ` Oleg Nesterov
2009-11-13 20:15 ` Roland McGrath
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