signal: Simplify tracehook_report_syscall_exit
Replace user_single_step_siginfo with user_single_step_report
that allocates siginfo structure on the stack and sends it.
This allows tracehook_report_syscall_exit to become a simple
if statement that calls user_single_step_report or ptrace_report_syscall
depending on the value of step.
Update the default helper function now called user_single_step_report
to explicitly set si_code to SI_USER and to set si_uid and si_pid to 0.
The default helper has always been doing this (using memset) but it
was far from obvious.
The powerpc helper can now just call force_sig_fault.
The x86 helper can now just call send_sigtrap.
Unfortunately the default implementation of user_single_step_report
can not use force_sig_fault as it does not use a SIGTRAP si_code.
So it has to carefully setup the siginfo and use use force_sig_info.
The net result is code that is easier to understand and simpler
to maintain.
Ref: 85ec7fd9f8e5 ("ptrace: introduce user_single_step_siginfo() helper")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 05589a3..40b0b4c 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -123,15 +123,10 @@
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
- if (step) {
- siginfo_t info;
- clear_siginfo(&info);
- user_single_step_siginfo(current, regs, &info);
- force_sig_info(SIGTRAP, &info, current);
- return;
- }
-
- ptrace_report_syscall(regs);
+ if (step)
+ user_single_step_report(regs);
+ else
+ ptrace_report_syscall(regs);
}
/**