linux-kernel - Re: [PATCH 0/2] tracing/wprobe: Fix to avoid inifinite watchpoint exception on arm64

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20251110135844.1c205d59be44d76169fc5e54@kernel.org>
Date: Mon, 10 Nov 2025 13:58:44 +0900
From: Masami Hiramatsu (Google) <mhiramat@...nel.org>
To: Ingo Molnar <mingo@...hat.com>, Will Deacon <will@...nel.org>, Kyle Huey
 <khuey@...ehuey.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Arnaldo Carvalho de Melo
 <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, Steven Rostedt
 <rostedt@...dmis.org>, Mark Rutland <mark.rutland@....com>, Alexander
 Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa
 <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>, Adrian Hunter
 <adrian.hunter@...el.com>, Mathieu Desnoyers
 <mathieu.desnoyers@...icios.com>, linux-perf-users@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org, Will
 Deacon <will@...nel.org>, Catalin Marinas <catalin.marinas@....com>,
 linux-arm-kernel@...ts.infradead.org, "Masami Hiramatsu (Google)"
 <mhiramat@...nel.org>
Subject: Re: [PATCH 0/2] tracing/wprobe: Fix to avoid inifinite watchpoint
 exception on arm64

Ingo, Will, Ping?

I also found that Kyle made a change on this area recently.

Thank you,

On Thu, 30 Oct 2025 12:26:55 +0900
"Masami Hiramatsu (Google)" <mhiramat@...nel.org> wrote:

> Hi,
> 
> Here are patches which fixes a wprobe bug reported by Mark Brown on
> arm64[1]. The root cause was that the infinite watchpoint exception on
> the same instruction, because arm64 watchpoint exception happens before
> the memory access has done, it needs to configure a single-step after
> calling overflow handler. It does that only for the default overflow
> handlers, and not for custom overflow handler registered via
> hw_breakpoint interface.
> 
> [1] https://lore.kernel.org/all/aPvwGhMBJqMKcC9D@finisterre.sirena.org.uk/
> 
> To fix this issue, this series introduces default_overflow_compatible
> flag in the perf_event and use it for identifying default overflow
> handlers instead of checking handler functions everytime[1/2], and
> set it in wprobe[2/2].
> 
> Thank you,
> 
> ---
> 
> Masami Hiramatsu (Google) (2):
>       perf: Introduce default_overflow_compatible flag
>       tracing: wprobe: Make wprobe_handler default overflow_handler compatible
> 
> 
>  include/linux/perf_event.h  |    9 ++-------
>  kernel/events/core.c        |    2 ++
>  kernel/trace/trace_wprobe.c |    7 +++++++
>  3 files changed, 11 insertions(+), 7 deletions(-)
> 
> --
> Masami Hiramatsu (Google) <mhiramat@...nel.org>


-- 
Masami Hiramatsu (Google) <mhiramat@...nel.org>