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From: Yafang Shao <laoar.shao@gmail.com>
To: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org, ebiederm@xmission.com,
	alexei.starovoitov@gmail.com, rostedt@goodmis.org,
	catalin.marinas@arm.com, penguin-kernel@i-love.sakura.ne.jp,
	linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org, audit@vger.kernel.org,
	linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
	bpf@vger.kernel.org, netdev@vger.kernel.org,
	dri-devel@lists.freedesktop.org,
	Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v4 07/11] mm/kmemleak: Replace strncpy() with __get_task_comm()
Date: Mon, 29 Jul 2024 10:37:15 +0800	[thread overview]
Message-ID: <20240729023719.1933-8-laoar.shao@gmail.com> (raw)
In-Reply-To: <20240729023719.1933-1-laoar.shao@gmail.com>

Since task lock was dropped from __get_task_comm(), it's safe to call it
from kmemleak.

Using __get_task_comm() to read the task comm ensures that the name is
always NUL-terminated, regardless of the source string. This approach also
facilitates future extensions to the task comm.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
 mm/kmemleak.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index d5b6fba44fc9..ef29aaab88a0 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -663,13 +663,7 @@ static struct kmemleak_object *__alloc_object(gfp_t gfp)
 		strncpy(object->comm, "softirq", sizeof(object->comm));
 	} else {
 		object->pid = current->pid;
-		/*
-		 * There is a small chance of a race with set_task_comm(),
-		 * however using get_task_comm() here may cause locking
-		 * dependency issues with current->alloc_lock. In the worst
-		 * case, the command line is not correct.
-		 */
-		strncpy(object->comm, current->comm, sizeof(object->comm));
+		__get_task_comm(object->comm, sizeof(object->comm), current);
 	}
 
 	/* kernel backtrace */
-- 
2.43.5


  parent reply	other threads:[~2024-07-29  2:45 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-29  2:37 [PATCH resend v4 00/11] Improve the copy of task comm Yafang Shao
2024-07-29  2:37 ` [PATCH v4 01/11] fs/exec: Drop task_lock() inside __get_task_comm() Yafang Shao
2024-07-29  2:37 ` [PATCH v4 02/11] auditsc: Replace memcpy() with __get_task_comm() Yafang Shao
2024-07-29  2:37 ` [PATCH v4 03/11] security: " Yafang Shao
2024-07-29  2:37 ` [PATCH v4 04/11] bpftool: Ensure task comm is always NUL-terminated Yafang Shao
2024-07-29  2:37 ` [PATCH v4 05/11] mm/util: Fix possible race condition in kstrdup() Yafang Shao
2024-07-29  2:37 ` [PATCH v4 06/11] mm/util: Deduplicate code in {kstrdup,kstrndup,kmemdup_nul} Yafang Shao
2024-07-29  2:37 ` Yafang Shao [this message]
2024-07-29  2:37 ` [PATCH v4 08/11] tsacct: Replace strncpy() with __get_task_comm() Yafang Shao
2024-07-29  2:37 ` [PATCH v4 09/11] tracing: " Yafang Shao
2024-07-29  2:37 ` [PATCH v4 10/11] net: Replace strcpy() " Yafang Shao
2024-07-29  2:37 ` [PATCH v4 11/11] drm: " Yafang Shao
2024-07-29  9:29 ` [PATCH resend v4 00/11] Improve the copy of task comm Jani Nikula
2024-07-29 11:45   ` Yafang Shao
2024-07-31  0:59 ` Andrew Morton
2024-07-31  2:14   ` Yafang Shao
  -- strict thread matches above, loose matches on Subject: below --
2024-06-28  8:57 [PATCH " Yafang Shao
2024-06-28  9:05 ` [PATCH v4 01/11] fs/exec: Drop task_lock() inside __get_task_comm() Yafang Shao
2024-06-28  9:05   ` [PATCH v4 07/11] mm/kmemleak: Replace strncpy() with __get_task_comm() Yafang Shao

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