[PATCHv2 bpf-next 1/2] arm64/ftrace,bpf: Fix partial regs after bpf_prog_run

[Steven Rostedt]

On Fri,  9 Jan 2026 10:34:53 +0100
Jiri Olsa <jolsa at kernel.org> wrote:

> Mahe reported issue with bpf_override_return helper not working when
> executed from kprobe.multi bpf program on arm.
> 
> The problem is that on arm we use alternate storage for pt_regs object
> that is passed to bpf_prog_run and if any register is changed (which
> is the case of bpf_override_return) it's not propagated back to actual
> pt_regs object.
> 
> Fixing this by introducing and calling ftrace_partial_regs_update function
> to propagate the values of changed registers (ip and stack).
> 
> Reported-by: Mahe Tardy <mahe.tardy at gmail.com>
> Signed-off-by: Jiri Olsa <jolsa at kernel.org>
> ---

Reviewed-by: Steven Rostedt (Google) <rostedt at goodmis.org>

-- Steve