From: sashiko-bot@kernel.org
To: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org
Subject: Re: [PATCH v15 11/12] tracing/wprobe: Support BTF typecast in fetchargs
Date: Mon, 07 Sep 2026 04:03:54 +0000 [thread overview]
Message-ID: <20260907040354.AF62D1F00A3A@smtp.kernel.org> (raw)
In-Reply-To: <178875290158.93794.6123987120712635214.stgit@devnote2>
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Allow BTF typecast syntax (STRUCT)FETCHARG->MEMBER in wprobe event
> fetchargs. Previously, handle_typecast() rejected any probe context
> that was not a function entry/return or tracepoint event probe.
>
> Wprobe events use $addr (the accessed address) and $value (the value
> at that address). By enabling BTF typecast, users can now cast these
> to a concrete struct type and access its fields directly. For example:
>
> echo 'w:watch rw@-1:8 dflag=(dentry)$addr->d_flags' >> dynamic_events
>
> With a set_wprobe trigger pointing the watchpoint at a dentry address,
> the resulting trace shows d_flags being accessed at that location.
>
> Note that $addr and $value are restricted to kernel-space memory,
> which is consistent with the existing TPARG_FL_KERNEL flag used when
> parsing wprobe fetchargs.
>
> Assisted-by: Antigravity:gemini-3.8-flash
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/178875277830.93794.14247844688761142429.stgit@devnote2?part=11
next prev parent reply other threads:[~2026-09-07 4:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-07 3:46 [PATCH v15 00/12] tracing: wprobe: x86: Add wprobe for watchpoint Masami Hiramatsu (Google)
2026-09-07 3:46 ` [PATCH v15 01/12] x86/mce: Fix hardware debug register corruption on task migration Masami Hiramatsu (Google)
2026-09-07 3:57 ` sashiko-bot
2026-09-07 3:46 ` [PATCH v15 02/12] x86/hw_breakpoints: Make DR7 updates NMI safe Masami Hiramatsu (Google)
2026-09-07 4:00 ` sashiko-bot
2026-09-07 3:46 ` [PATCH v15 03/12] x86/hw_breakpoints: Add arch_modify_local_hw_breakpoint_addr() API Masami Hiramatsu (Google)
2026-09-07 4:02 ` sashiko-bot
2026-09-07 3:47 ` [PATCH v15 04/12] HWBP: Add modify_local_hw_breakpoint_addr() API Masami Hiramatsu (Google)
2026-09-07 4:04 ` sashiko-bot
2026-09-07 3:47 ` [PATCH v15 05/12] tracing/wprobe: Add wprobe (watchpoint probe) trace event support Masami Hiramatsu (Google)
2026-09-07 4:15 ` sashiko-bot
2026-09-07 3:47 ` [PATCH v15 06/12] x86: hw_breakpoint: Add a kconfig to clarify when a breakpoint fires Masami Hiramatsu (Google)
2026-09-07 3:52 ` sashiko-bot
2026-09-07 3:47 ` [PATCH v15 07/12] selftests: tracing: Add a basic testcase for wprobe Masami Hiramatsu (Google)
2026-09-07 3:53 ` sashiko-bot
2026-09-07 3:47 ` [PATCH v15 08/12] selftests: tracing: Add syntax " Masami Hiramatsu (Google)
2026-09-07 3:58 ` sashiko-bot
2026-09-07 3:47 ` [PATCH v15 09/12] tracing/wprobe: Add set_wprobe and clear_wprobe event triggers Masami Hiramatsu (Google)
2026-09-07 4:10 ` sashiko-bot
2026-09-07 3:48 ` [PATCH v15 10/12] selftests: tracing: Add wprobe trigger testcase Masami Hiramatsu (Google)
2026-09-07 3:58 ` sashiko-bot
2026-09-07 3:48 ` [PATCH v15 11/12] tracing/wprobe: Support BTF typecast in fetchargs Masami Hiramatsu (Google)
2026-09-07 4:03 ` sashiko-bot [this message]
2026-09-07 3:48 ` [PATCH v15 12/12] tracing/wprobe: Support BTF struct offset resolution in set_wprobe trigger Masami Hiramatsu (Google)
2026-09-07 4:06 ` sashiko-bot
2026-09-11 7:27 ` [PATCH v15 00/12] tracing: wprobe: x86: Add wprobe for watchpoint Jinchao Wang
2026-09-12 13:36 ` Masami Hiramatsu
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