From: Steven Rostedt <rostedt@goodmis.org>
To: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org,
Florent Revest <revest@chromium.org>,
Mark Rutland <mark.rutland@arm.com>,
Will Deacon <will@kernel.org>
Subject: Re: [RFC PATCH 1/9] fprobe: Pass entry_data to handlers
Date: Tue, 17 Jan 2023 20:43:09 -0500 [thread overview]
Message-ID: <20230117204309.1cd8f20f@gandalf.local.home> (raw)
In-Reply-To: <166792256330.919356.14776044963704066797.stgit@devnote3>
On Wed, 9 Nov 2022 00:49:23 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index e8143e368074..fa25d09c9d57 100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -17,14 +17,16 @@
> struct fprobe_rethook_node {
> struct rethook_node node;
> unsigned long entry_ip;
> + char data[];
> };
>
> static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
> struct ftrace_ops *ops, struct ftrace_regs *fregs)
> {
> struct fprobe_rethook_node *fpr;
> - struct rethook_node *rh;
> + struct rethook_node *rh = NULL;
> struct fprobe *fp;
> + void *entry_data = NULL;
> int bit;
>
> fp = container_of(ops, struct fprobe, ops);
> @@ -37,9 +39,6 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
> return;
> }
>
> - if (fp->entry_handler)
> - fp->entry_handler(fp, ip, ftrace_get_regs(fregs));
> -
> if (fp->exit_handler) {
> rh = rethook_try_get(fp->rethook);
> if (!rh) {
> @@ -48,9 +47,16 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
> }
> fpr = container_of(rh, struct fprobe_rethook_node, node);
> fpr->entry_ip = ip;
> - rethook_hook(rh, ftrace_get_regs(fregs), true);
> + if (fp->entry_data_size)
> + entry_data = fpr->data;
> }
>
> + if (fp->entry_handler)
> + fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data);
> +
> + if (rh)
> + rethook_hook(rh, ftrace_get_regs(fregs), true);
> +
> out:
> ftrace_test_recursion_unlock(bit);
> }
> @@ -81,7 +87,8 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data,
>
> fpr = container_of(rh, struct fprobe_rethook_node, node);
>
> - fp->exit_handler(fp, fpr->entry_ip, regs);
> + fp->exit_handler(fp, fpr->entry_ip, regs,
> + fp->entry_data_size ? (void *)fpr->data : NULL);
> }
> NOKPROBE_SYMBOL(fprobe_exit_handler);
>
> @@ -146,7 +153,7 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
> for (i = 0; i < size; i++) {
> struct fprobe_rethook_node *node;
>
> - node = kzalloc(sizeof(*node), GFP_KERNEL);
> + node = kzalloc(sizeof(*node) + fp->entry_data_size, GFP_KERNEL);
node = kzalloc(struct_size(node, data, fp->entry_data_size), GFP_KERNEL);
Should use struct_size() for any tail structure allocations.
-- Steve
> if (!node) {
> rethook_free(fp->rethook);
> fp->rethook = NULL;
> diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
> index e0381b3ec410..34fa5a5bbda1 100644
next prev parent reply other threads:[~2023-01-18 1:44 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-08 15:49 [RFC PATCH 0/9] tracing: Add fprobe events Masami Hiramatsu (Google)
2022-11-08 15:49 ` [RFC PATCH 1/9] fprobe: Pass entry_data to handlers Masami Hiramatsu (Google)
2023-01-18 1:43 ` Steven Rostedt [this message]
2023-01-20 3:48 ` Masami Hiramatsu
2022-11-08 15:49 ` [RFC PATCH 2/9] lib/test_fprobe: Add private entry_data testcases Masami Hiramatsu (Google)
2022-11-08 15:49 ` [RFC PATCH 3/9] fprobe: Add nr_maxactive to specify rethook_node pool size Masami Hiramatsu (Google)
2022-11-08 15:49 ` [RFC PATCH 4/9] lib/test_fprobe: Add a test case for nr_maxactive Masami Hiramatsu (Google)
2022-11-08 15:49 ` [RFC PATCH 5/9] fprobe: Skip exit_handler if entry_handler returns !0 Masami Hiramatsu (Google)
2022-11-08 15:50 ` [RFC PATCH 6/9] lib/test_fprobe: Add a testcase for skipping exit_handler Masami Hiramatsu (Google)
2022-11-08 15:50 ` [RFC PATCH 7/9] docs: tracing: Update fprobe documentation Masami Hiramatsu (Google)
2022-11-08 15:50 ` [RFC PATCH 8/9] fprobe: Pass return address to the handlers Masami Hiramatsu (Google)
2022-11-08 15:50 ` [RFC PATCH 9/9] tracing/probes: Add fprobe-events Masami Hiramatsu (Google)
2023-01-18 22:43 ` Steven Rostedt
2023-01-20 11:55 ` Masami Hiramatsu
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