LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Petr Mladek <pmladek@suse.com>
To: Jiri Kosina <jikos@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Miroslav Benes <mbenes@suse.cz>
Cc: Joe Lawrence <joe.lawrence@redhat.com>,
	Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
	live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
	Petr Mladek <pmladek@suse.com>
Subject: [PATCH 3/3] livepatch: Use static buffer for debugging messages under rq lock
Date: Fri, 31 May 2019 09:41:47 +0200	[thread overview]
Message-ID: <20190531074147.27616-4-pmladek@suse.com> (raw)
In-Reply-To: <20190531074147.27616-1-pmladek@suse.com>

The err_buf array uses 128 bytes of stack space.  Move it off the stack
by making it static.  It's safe to use a shared buffer because
klp_try_switch_task() is called under klp_mutex.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
---
 kernel/livepatch/transition.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index 1bf362df76e1..5c4f0c1f826e 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -280,11 +280,11 @@ static int klp_check_stack(struct task_struct *task, char *err_buf)
  */
 static bool klp_try_switch_task(struct task_struct *task)
 {
+	static char err_buf[STACK_ERR_BUF_SIZE];
 	struct rq *rq;
 	struct rq_flags flags;
 	int ret;
 	bool success = false;
-	char err_buf[STACK_ERR_BUF_SIZE];
 
 	err_buf[0] = '\0';
 
@@ -327,7 +327,6 @@ static bool klp_try_switch_task(struct task_struct *task)
 		pr_debug("%s", err_buf);
 
 	return success;
-
 }
 
 /*
-- 
2.16.4


  parent reply	other threads:[~2019-05-31  7:42 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-31  7:41 [PATCH 0/3] livepatch: Clean up of reliable stacktrace warnings Petr Mladek
2019-05-31  7:41 ` [PATCH 1/3] stacktrace: Remove superfluous WARN_ONCE() from save_stack_trace_tsk_reliable() Petr Mladek
2019-05-31 12:25   ` Miroslav Benes
2019-05-31 19:27     ` Josh Poimboeuf
2019-05-31  7:41 ` [PATCH 2/3] livepatch: Remove duplicate warning about missing reliable stacktrace support Petr Mladek
2019-05-31 12:32   ` Miroslav Benes
2019-05-31 13:19     ` Petr Mladek
2019-05-31 13:29       ` Miroslav Benes
2019-05-31 19:37     ` Josh Poimboeuf
2019-05-31  7:41 ` Petr Mladek [this message]
2019-05-31 12:37   ` [PATCH 3/3] livepatch: Use static buffer for debugging messages under rq lock Miroslav Benes
2019-06-03  8:07     ` Petr Mladek
2019-05-31 19:39   ` Josh Poimboeuf
2019-06-06 13:27     ` Petr Mladek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190531074147.27616-4-pmladek@suse.com \
    --to=pmladek@suse.com \
    --cc=jikos@kernel.org \
    --cc=joe.lawrence@redhat.com \
    --cc=jpoimboe@redhat.com \
    --cc=kamalesh@linux.vnet.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=live-patching@vger.kernel.org \
    --cc=mbenes@suse.cz \
    --subject='Re: [PATCH 3/3] livepatch: Use static buffer for debugging messages under rq lock' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).