From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Namhyung Kim <namhyung@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: [for-next][PATCH 03/24] fgraph: Add comment to describe ftrace_graph_get_ret_stack
Date: Fri, 21 Dec 2018 12:56:21 -0500 [thread overview]
Message-ID: <20181221175655.732569750@goodmis.org> (raw)
In-Reply-To: 20181221175618.968519903@goodmis.org
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The ret_stack should not be accessed directly via the curr_ret_stack
variable on the task_struct. This is because the ret_stack is going to be
converted into a series of longs and not an array of ret_stack structures.
The way that a ret_stack should be retrieved is via the
ftrace_graph_get_ret_stack structure, but it needs to be documented on how
to use it.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/fgraph.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index a3704ec8b599..d4f04f0ca646 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -232,6 +232,17 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
return ret;
}
+/**
+ * ftrace_graph_get_ret_stack - return the entry of the shadow stack
+ * @task: The task to read the shadow stack from
+ * @idx: Index down the shadow stack
+ *
+ * Return the ret_struct on the shadow stack of the @task at the
+ * call graph at @idx starting with zero. If @idx is zero, it
+ * will return the last saved ret_stack entry. If it is greater than
+ * zero, it will return the corresponding ret_stack for the depth
+ * of saved return addresses.
+ */
struct ftrace_ret_stack *
ftrace_graph_get_ret_stack(struct task_struct *task, int idx)
{
--
2.19.2
next prev parent reply other threads:[~2018-12-21 17:58 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-21 17:56 [for-next][PATCH 00/24] tracing: Updates for the next (coming soon) merge window Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 01/24] ftrace: Allow ftrace_replace_code() to be schedulable Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 02/24] arm64: ftrace: Set FTRACE_MAY_SLEEP before ftrace_modify_all_code() Steven Rostedt
2018-12-21 17:56 ` Steven Rostedt [this message]
2018-12-21 17:56 ` [for-next][PATCH 04/24] x86/ftrace: Do not call function graph from dynamic trampolines Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 05/24] powerpc/frace: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack Steven Rostedt
2018-12-22 9:51 ` Michael Ellerman
2018-12-22 12:24 ` Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 06/24] sparc64: " Steven Rostedt
2018-12-21 18:24 ` David Miller
2018-12-21 19:29 ` Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 07/24] sh: ftrace: " Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 08/24] arm64: " Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 10/24] seq_buf: Use size_t for len in seq_buf_puts() Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 11/24] tracing: Fix ftrace_graph_get_ret_stack() to use task and not current Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 12/24] tracing: Remove unnecessary hist trigger struct field Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 13/24] tracing: Change strlen to sizeof for hist trigger static strings Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 14/24] tracing: Use var_refs[] for hist trigger reference checking Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 15/24] tracing: Remove open-coding of hist trigger var_ref management Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 16/24] tracing: Use hist triggers var_ref array to destroy var_refs Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 17/24] tracing: Remove hist trigger synth_var_refs Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 18/24] tracing: Add hist trigger comments for variable-related fields Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 19/24] tracing: Merge seq_print_sym_short() and seq_print_sym_offset() Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 21/24] tracing: Simplify printfing in seq_print_sym Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 23/24] string.h: Add strncmp_prefix() helper macro Steven Rostedt
2018-12-21 18:51 ` Linus Torvalds
2018-12-21 19:40 ` Steven Rostedt
2018-12-21 20:01 ` Linus Torvalds
2018-12-21 20:35 ` Steven Rostedt
2018-12-21 20:46 ` Joe Perches
2018-12-21 20:54 ` Steven Rostedt
2018-12-21 20:58 ` Andreas Schwab
2018-12-21 21:08 ` Steven Rostedt
2018-12-21 22:20 ` Joe Perches
2018-12-21 22:29 ` Linus Torvalds
2018-12-21 22:58 ` Steven Rostedt
2018-12-21 22:55 ` Steven Rostedt
2018-12-23 22:01 ` Rasmus Villemoes
2018-12-23 22:56 ` Steven Rostedt
2018-12-23 23:52 ` Rasmus Villemoes
2018-12-24 0:05 ` Steven Rostedt
2018-12-23 23:01 ` Joe Perches
2018-12-21 20:58 ` Steven Rostedt
[not found] ` <CAHk-=wjtkvFUuRNZU67KccuUKYHw=pYoDMQJ_9OVDFxOwmK9zQ@mail.gmail.com>
2018-12-21 20:55 ` Steven Rostedt
2018-12-21 22:08 ` Linus Torvalds
2018-12-21 22:48 ` Steven Rostedt
2018-12-21 22:57 ` Linus Torvalds
2018-12-21 23:03 ` Steven Rostedt
2018-12-22 10:20 ` Malcolm Priestley
2018-12-22 12:26 ` Steven Rostedt
2018-12-21 17:56 ` [for-next][PATCH 24/24] tracing: Use strncmp_prefix() helper for histogram code Steven Rostedt
[not found] ` <20181221175656.827708767@goodmis.org>
2018-12-21 18:00 ` [for-next][PATCH 09/24] seq_buf: Make seq_buf_puts() null-terminate the buffer Steven Rostedt
2018-12-21 18:05 ` Steven Rostedt
2018-12-27 5:25 ` Michael Ellerman
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