Re: [PATCHv2 bpf-next 1/2] arm64/ftrace,bpf: Fix partial regs after bpf_prog_run
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2026-01-09 16:17:43
Also in:
bpf, linux-trace-kernel
On Fri, 9 Jan 2026 10:34:53 +0100 Jiri Olsa [off-list ref] 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 <redacted> Signed-off-by: Jiri Olsa <jolsa@kernel.org> ---
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> -- Steve