From patchwork Mon Jun 3 19:07:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13684163 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B1B013C90E; Mon, 3 Jun 2024 19:07:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717441633; cv=none; b=kJWskCobuGYC20Z6YSEFTVE+mCOo6M33+53QltX7qX+pcAKQaGENK35IXWb74gz25hVBn7o2C6hCrsyAmh9965hl+FAF1fVRFL0rBC9auu/x0Xjdhetv8CHSIlWsHmB07xE8gfTI6db4VfRO5tJ/PBEaMHa9BYfsN5sUVV5xWic= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717441633; c=relaxed/simple; bh=ALL5BqhhQlUiOxD8vovKUC+mjaCtK7pnO3aAlaRI9eE=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=It0JD8RTYtZlxbip1WLsA5cUfCO7QTW5fzNY7qRWRikPFVFcP3ih8PDUEzeClH3LUiOIlElLLmm7DejPX+hHemgziNIZLsCl9wo6G4u1AWUhzVhQq6vf1XlBnyRz3S0+QQqf79jioGLoHA7tkh+85wmkXXbebrRQI7n4dU+TCrQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E8E1C4E673; Mon, 3 Jun 2024 19:07:12 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1sED2d-00000009TsS-0Whs; Mon, 03 Jun 2024 15:08:23 -0400 Message-ID: <20240603190822.991720703@goodmis.org> User-Agent: quilt/0.68 Date: Mon, 03 Jun 2024 15:07:17 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Alexei Starovoitov , Florent Revest , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v3 13/27] function_graph: Add pid tracing back to function graph tracer References: <20240603190704.663840775@goodmis.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Steven Rostedt (Google)" Now that the function_graph has a main callback that handles the function graph subops tracing, it no longer honors the pid filtering of ftrace. Add back this logic in the function_graph code to update the gops callback for the entry function to test if it should trace the current task or not. Signed-off-by: Steven Rostedt (Google) --- include/linux/ftrace.h | 2 ++ kernel/trace/fgraph.c | 40 ++++++++++++++++++++++++++++++++++ kernel/trace/ftrace.c | 5 +++-- kernel/trace/ftrace_internal.h | 2 ++ 4 files changed, 47 insertions(+), 2 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 8f865689e868..e31ec8516de1 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -1040,6 +1040,7 @@ typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *, struct fgraph_ops *); /* entry */ extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, struct fgraph_ops *gops); +bool ftrace_pids_enabled(struct ftrace_ops *ops); #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -1048,6 +1049,7 @@ struct fgraph_ops { trace_func_graph_ret_t retfunc; struct ftrace_ops ops; /* for the hash lists */ void *private; + trace_func_graph_ent_t saved_func; int idx; }; diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 3ef6db53c0bf..30bed20c655f 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -854,6 +854,41 @@ void ftrace_graph_exit_task(struct task_struct *t) kfree(ret_stack); } +static int fgraph_pid_func(struct ftrace_graph_ent *trace, + struct fgraph_ops *gops) +{ + struct trace_array *tr = gops->ops.private; + int pid; + + if (tr) { + pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); + if (pid == FTRACE_PID_IGNORE) + return 0; + if (pid != FTRACE_PID_TRACE && + pid != current->pid) + return 0; + } + + return gops->saved_func(trace, gops); +} + +void fgraph_update_pid_func(void) +{ + struct fgraph_ops *gops; + struct ftrace_ops *op; + + if (!(graph_ops.flags & FTRACE_OPS_FL_INITIALIZED)) + return; + + list_for_each_entry(op, &graph_ops.subop_list, list) { + if (op->flags & FTRACE_OPS_FL_PID) { + gops = container_of(op, struct fgraph_ops, ops); + gops->entryfunc = ftrace_pids_enabled(op) ? + fgraph_pid_func : gops->saved_func; + } + } +} + /* Allocate a return stack for each task */ static int start_graph_tracing(void) { @@ -931,11 +966,15 @@ int register_ftrace_graph(struct fgraph_ops *gops) command = FTRACE_START_FUNC_RET; } + /* Always save the function, and reset at unregistering */ + gops->saved_func = gops->entryfunc; + ret = ftrace_startup_subops(&graph_ops, &gops->ops, command); error: if (ret) { fgraph_array[i] = &fgraph_stub; ftrace_graph_active--; + gops->saved_func = NULL; } out: mutex_unlock(&ftrace_lock); @@ -979,5 +1018,6 @@ void unregister_ftrace_graph(struct fgraph_ops *gops) unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); } out: + gops->saved_func = NULL; mutex_unlock(&ftrace_lock); } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 58e0f4bc0241..da7e6abf48b4 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -100,7 +100,7 @@ struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; /* What to set function_trace_op to */ static struct ftrace_ops *set_function_trace_op; -static bool ftrace_pids_enabled(struct ftrace_ops *ops) +bool ftrace_pids_enabled(struct ftrace_ops *ops) { struct trace_array *tr; @@ -402,10 +402,11 @@ static void ftrace_update_pid_func(void) if (op->flags & FTRACE_OPS_FL_PID) { op->func = ftrace_pids_enabled(op) ? ftrace_pid_func : op->saved_func; - ftrace_update_trampoline(op); } } while_for_each_ftrace_op(op); + fgraph_update_pid_func(); + update_ftrace_function(); } diff --git a/kernel/trace/ftrace_internal.h b/kernel/trace/ftrace_internal.h index cdfd12c44ab4..bfba10c2fcf1 100644 --- a/kernel/trace/ftrace_internal.h +++ b/kernel/trace/ftrace_internal.h @@ -43,8 +43,10 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern int ftrace_graph_active; +extern void fgraph_update_pid_func(void); #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ # define ftrace_graph_active 0 +static inline void fgraph_update_pid_func(void) {} #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #else /* !CONFIG_FUNCTION_TRACER */