[PATCH] arm64: stacktrace: fix the usage of ftrace_graph_ret_addr()

[Mark Rutland]

Hi Steve,

On Mon, Jun 24, 2024 at 04:17:41PM -0400, Steven Rostedt wrote:
> On Wed, 19 Jun 2024 13:43:18 +0100
> Will Deacon <will at kernel.org> wrote:
> 
> > > Catalin, Will, do you have any preference?  
> > 
> > I think it makes most sense if this patch travels together with
> > 29c1c24a2707 ("function_graph: Fix up ftrace_graph_ret_addr()"), so that
> > would be via Steve's tree. In which case:
> 
> That makes sense to me. I'll go around pulling in all the updates to the
> arch code here (with the respective acks).

Are you still planning to pick this up? On next-20240829 the ftrace
tests blow up (as below) due to having the core ftrace change to
ftrace_graph_ret_addr() but lacking the arm64 fix.

Splat on next-20240829:

  [2] Basic test for tracers
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 198 at arch/arm64/kernel/stacktrace.c:112 arch_stack_walk+0x1d0/0x350
  Modules linked in:
  CPU: 0 UID: 0 PID: 198 Comm: ftracetest Not tainted 6.11.0-rc5-next-20240829 #1
  Hardware name: linux,dummy-virt (DT)
  pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : arch_stack_walk+0x1d0/0x350
  lr : arch_stack_walk+0x1c4/0x350
  sp : ffff800080003e10
  x29: ffff800080003e10 x28: ffff800080003fe0 x27: ffff800080003eb8
  x26: ffff000003813600 x25: ffff800080004000 x24: ffff80008002ebd8
  x23: ffff800080003ed8 x22: ffff800080023c78 x21: ffff80008002ebd8
  x20: ffff800080003f40 x19: ffff800080003f30 x18: 0000000082000000
  x17: 0000000000000000 x16: ffff800080000000 x15: 00003d0900000000
  x14: 00000000000c3500 x13: 0000000000000000 x12: 0001f4e457e39c1c
  x11: ffff800082f06ca8 x10: ffff800080003f30 x9 : ffff80008002ebd8
  x8 : ffff800080003db8 x7 : 7fffffffffffffff x6 : 0000000006dd7418
  x5 : 0000000000000023 x4 : ffff800080003e88 x3 : ffff800080003fe0
  x2 : ffff80008002ebd8 x1 : 0000000000000000 x0 : ffff80008002ebd8
  Call trace:
   arch_stack_walk+0x1d0/0x350
   return_address+0x40/0x80
   trace_hardirqs_on+0x8c/0x190
   handle_softirqs+0xf0/0x400
  ---[ end trace 0000000000000000 ]---

Mark.