linux-kernel - [PATCH v2 1/5] kernel: Remove get_task_comm() and print task comm directly

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Message-Id: <20241219023452.69907-2-laoar.shao@gmail.com>
Date: Thu, 19 Dec 2024 10:34:48 +0800
From: Yafang Shao <laoar.shao@...il.com>
To: akpm@...ux-foundation.org
Cc: torvalds@...ux-foundation.org,
	pmladek@...e.com,
	kvalo@...nel.org,
	bp@...en8.de,
	andriy.shevchenko@...ux.intel.com,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	linux-security-module@...r.kernel.org,
	x86@...nel.org,
	linux-snps-arc@...ts.infradead.org,
	linux-wireless@...r.kernel.org,
	intel-gfx@...ts.freedesktop.org,
	intel-xe@...ts.freedesktop.org,
	nouveau@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org,
	ocfs2-devel@...ts.linux.dev,
	Yafang Shao <laoar.shao@...il.com>,
	Serge Hallyn <serge@...lyn.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Darren Hart <dvhart@...radead.org>,
	Davidlohr Bueso <dave@...olabs.net>,
	André Almeida <andrealmeid@...lia.com>
Subject: [PATCH v2 1/5] kernel: Remove get_task_comm() and print task comm directly

Since task->comm is guaranteed to be NUL-terminated, we can print it
directly without the need to copy it into a separate buffer. This
simplifies the code and avoids unnecessary operations.

Signed-off-by: Yafang Shao <laoar.shao@...il.com>
Cc: Serge Hallyn <serge@...lyn.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Darren Hart <dvhart@...radead.org>
Cc: Davidlohr Bueso <dave@...olabs.net>
Cc: "André Almeida" <andrealmeid@...lia.com>
---
 kernel/capability.c     | 8 ++------
 kernel/futex/waitwake.c | 3 +--
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/kernel/capability.c b/kernel/capability.c
index dac4df77e376..e089d2628c29 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -38,10 +38,8 @@ __setup("no_file_caps", file_caps_disable);
 
 static void warn_legacy_capability_use(void)
 {
-	char name[sizeof(current->comm)];
-
 	pr_info_once("warning: `%s' uses 32-bit capabilities (legacy support in use)\n",
-		     get_task_comm(name, current));
+		     current->comm);
 }
 
 /*
@@ -62,10 +60,8 @@ static void warn_legacy_capability_use(void)
 
 static void warn_deprecated_v2(void)
 {
-	char name[sizeof(current->comm)];
-
 	pr_info_once("warning: `%s' uses deprecated v2 capabilities in a way that may be insecure\n",
-		     get_task_comm(name, current));
+		     current->comm);
 }
 
 /*
diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c
index 3a10375d9521..eb86a7ade06a 100644
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -210,13 +210,12 @@ static int futex_atomic_op_inuser(unsigned int encoded_op, u32 __user *uaddr)
 
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) {
 		if (oparg < 0 || oparg > 31) {
-			char comm[sizeof(current->comm)];
 			/*
 			 * kill this print and return -EINVAL when userspace
 			 * is sane again
 			 */
 			pr_info_ratelimited("futex_wake_op: %s tries to shift op by %d; fix this program\n",
-					get_task_comm(comm, current), oparg);
+					    current->comm, oparg);
 			oparg &= 31;
 		}
 		oparg = 1 << oparg;
-- 
2.43.5