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

[Steven Rostedt]

On Thu, 29 Aug 2024 18:54:01 +0100
Mark Rutland <mark.rutland at arm.com> wrote:

> 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:

Ah, I didn't check to see if it was sent to linux-trace-kernel, so it
wasn't in patchwork, hence I forgot :-p

I can add it this week.

-- Steve


> 
>   [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.