From: Steven Rostedt <rostedt@goodmis.org>
To: LKML <linux-kernel@vger.kernel.org>,
Linux trace kernel <linux-trace-kernel@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Ryan Roberts <ryan.roberts@arm.com>
Subject: [PATCH] fgraph: Separate size of ret_stack from PAGE_SIZE
Date: Sat, 19 Oct 2024 15:29:51 -0400 [thread overview]
Message-ID: <20241019152951.053f9646@rorschach.local.home> (raw)
From: Steven Rostedt <rostedt@goodmis.org>
The ret_stack (shadow stack used by function graph infrastructure) is
currently defined as PAGE_SIZE. But some architectures which have 64K
PAGE_SIZE, this is way overkill. Also there's an effort to allow the
PAGE_SIZE to be defined at boot up.
Hard code it for now to 4096. In the future, this size may change and even
be dependent on specific architectures.
Link: https://lore.kernel.org/all/e5067bb8-0fcd-4739-9bca-0e872037d5a1@arm.com/
Suggested-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/fgraph.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index ee829d65f301..51e81b299a0d 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -153,7 +153,7 @@ enum {
* SHADOW_STACK_OFFSET: The size in long words of the shadow stack
* SHADOW_STACK_MAX_OFFSET: The max offset of the stack for a new frame to be added
*/
-#define SHADOW_STACK_SIZE (PAGE_SIZE)
+#define SHADOW_STACK_SIZE (4096)
#define SHADOW_STACK_OFFSET (SHADOW_STACK_SIZE / sizeof(long))
/* Leave on a buffer at the end */
#define SHADOW_STACK_MAX_OFFSET \
--
2.45.2
next reply other threads:[~2024-10-19 19:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-19 19:29 Steven Rostedt [this message]
2024-10-21 8:01 ` [PATCH] fgraph: Separate size of ret_stack from PAGE_SIZE Ryan Roberts
2024-10-21 14:58 ` Masami Hiramatsu
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