[PATCH] powerpc: Enable execve syscall exit tracepoint

[Michael Ellerman]

On Thu, 9 Jun 2022 16:03:28 +0530, Naveen N. Rao wrote:
> On execve[at], we are zero'ing out most of the thread register state
> including gpr[0], which contains the syscall number. Due to this, we
> fail to trigger the syscall exit tracepoint properly. Fix this by
> retaining gpr[0] in the thread register state.
> 
> Before this patch:
>   # tail /sys/kernel/debug/tracing/trace
> 	       cat-123     [000] .....    61.449351: sys_execve(filename:
>   7fffa6b23448, argv: 7fffa6b233e0, envp: 7fffa6b233f8)
> 	       cat-124     [000] .....    62.428481: sys_execve(filename:
>   7fffa6b23448, argv: 7fffa6b233e0, envp: 7fffa6b233f8)
> 	      echo-125     [000] .....    65.813702: sys_execve(filename:
>   7fffa6b23378, argv: 7fffa6b233a0, envp: 7fffa6b233b0)
> 	      echo-125     [000] .....    65.822214: sys_execveat(fd: 0,
>   filename: 1009ac48, argv: 7ffff65d0c98, envp: 7ffff65d0ca8, flags: 0)
> 
> [...]

Applied to powerpc/fixes.

[1/1] powerpc: Enable execve syscall exit tracepoint
      https://git.kernel.org/powerpc/c/ec6d0dde71d760aa60316f8d1c9a1b0d99213529

cheers