Re: [PATCH 1/4] sparc64: kprobes: Single-step from an executable instruction slot

[Stian Halseth <stian@itx.no>]

[-- Attachment #1: Type: text/plain, Size: 1095 bytes --]

Hi Masami,

On Fri, 2026-11-13 at 18:32 +0900, Masami Hiramatsu (Google) wrote:
> 
> With this change, the p->ainsn.insn becomes NULL here when kill_kprobe()
> calls this function because (1) init.text is removed or (2) probed module
> is unloaded.
> 
> If another module is loaded at the same region and another kprobe
> is registered at the same address, register_aggr_kprobe() ->
> init_aggr_kprobe() -> flush_insn_slot(NULL) is called. This can
> cause a problem because it is defined as:
> 
> #define flush_insn_slot(p)		\
> do { 	flushi(&(p)->ainsn.insn[0]);	\
> 	flushi(&(p)->ainsn.insn[1]);	\
> 	flushi(&(p)->ainsn.insn[2]);	\
> } while (0)
> 
> Since the flush_insn_slot() is only needed if p->ainsn.insn is
> embedded in the struct kprobe, as this changed it to insn_slot,
> we don't need this macro anymore.
> So you should update it as same as other arch like:
> 
> #define flush_insn_slot(p) do { } while (0)

Thanks for the review, I'll test and adopt that change in v2.

I'll check for any other feedback, then prepare the v2 later today.

/Stian


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 228 bytes --]