From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 859A7315D45 for ; Sat, 6 Sep 2025 21:25:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757193935; cv=none; b=kCmEQ0dtuwPqA0GTs0j1fsjm4ymOn74pYEnsAl8tMTgZ9XhotvOopMKCicMISwhWMSnZOcoFbjBi7RxvDP2vuzgh02ITaZmeoZ1ww4lnros4vgt2s/0oP9LE0jThRyR6crBH6UONznSXhwoThZvDSoJTXxpUyd5HL2ECT5+mCBk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757193935; c=relaxed/simple; bh=N4iyWQEc3jtK01rT2CcmXDUdS61n01OLfjLbiGVh1UM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MVx7YvR4eH7KmG8k7khJly7IPd0A8GVeugrRCmie/kWLbk/h3hkUNbtyHQqOwfio9QSGKousUPRcr2giN8R6QCHALZ8TZYcGeGbLlFycV5m2Rcuu8zarN8VZxqeAhMwXBMr+PCZIwsvrwCOqZ5jxyhIO18AZR8eSttFgj5m548A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bdfmrQy5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bdfmrQy5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B746AC4CEF5; Sat, 6 Sep 2025 21:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757193935; bh=N4iyWQEc3jtK01rT2CcmXDUdS61n01OLfjLbiGVh1UM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bdfmrQy52dapnyp6r+uQ7hga3Y+gxzRT89IbJBV7GAt+0XIRqtGj29gUou93QnAxV HJEtxv6mxWdMf4oe7i+uRiHBK8N8YdvpWkHnSEl1t1+amUr9KKwpAqN+KrL0iHBhZ/ +y94IN+3MsNNcvfDBtOWnxtatp6wcaw+7Id3u37gV/Yd5gUThz3cP3at1L26uyYJlh OACfL6ovhzGYfjZdRxC/Hcd//L9vgQ4MSLGeNdfXBL8O5HL/QIrja3zfpY+SeozD0n 0GV1P/NspHegZdOWWGLl4DINQRyjVSMfkkW0rrBL7UoENwjOL5QvQt2290K37oL89p Fm7QkD5dAr+6Q== From: Sasha Levin To: stable@vger.kernel.org Cc: Vlastimil Babka , Harry Yoo , Sasha Levin Subject: [PATCH 6.12.y 3/4] mm, slab: cleanup slab_bug() parameters Date: Sat, 6 Sep 2025 17:25:29 -0400 Message-ID: <20250906212530.302670-3-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250906212530.302670-1-sashal@kernel.org> References: <2025090618-patient-manlike-340f@gregkh> <20250906212530.302670-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Vlastimil Babka [ Upstream commit 4b183dd9359d5772446cb634b12a383bed98c4fc ] slab_err() has variadic printf arguments but instead of passing them to slab_bug() it does vsnprintf() to a buffer and passes %s, buf. To allow passing them directly, turn slab_bug() to __slab_bug() with a va_list parameter, and slab_bug() a wrapper with fmt, ... parameters. Then slab_err() can call __slab_bug() without the intermediate buffer. Also constify fmt everywhere, which also simplifies object_err()'s call to slab_bug(). Signed-off-by: Vlastimil Babka Reviewed-by: Harry Yoo Stable-dep-of: b4efccec8d06 ("mm/slub: avoid accessing metadata when pointer is invalid in object_err()") Signed-off-by: Sasha Levin --- mm/slub.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index f6323fac6a026..39fb2b930fdf7 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1027,12 +1027,12 @@ void skip_orig_size_check(struct kmem_cache *s, const void *object) set_orig_size(s, (void *)object, s->object_size); } -static void slab_bug(struct kmem_cache *s, char *fmt, ...) +static void __slab_bug(struct kmem_cache *s, const char *fmt, va_list argsp) { struct va_format vaf; va_list args; - va_start(args, fmt); + va_copy(args, argsp); vaf.fmt = fmt; vaf.va = &args; pr_err("=============================================================================\n"); @@ -1041,8 +1041,17 @@ static void slab_bug(struct kmem_cache *s, char *fmt, ...) va_end(args); } +static void slab_bug(struct kmem_cache *s, const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + __slab_bug(s, fmt, args); + va_end(args); +} + __printf(2, 3) -static void slab_fix(struct kmem_cache *s, char *fmt, ...) +static void slab_fix(struct kmem_cache *s, const char *fmt, ...) { struct va_format vaf; va_list args; @@ -1098,12 +1107,12 @@ static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p) } static void object_err(struct kmem_cache *s, struct slab *slab, - u8 *object, char *reason) + u8 *object, const char *reason) { if (slab_add_kunit_errors()) return; - slab_bug(s, "%s", reason); + slab_bug(s, reason); print_trailer(s, slab, object); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); @@ -1139,15 +1148,14 @@ static __printf(3, 4) void slab_err(struct kmem_cache *s, struct slab *slab, const char *fmt, ...) { va_list args; - char buf[100]; if (slab_add_kunit_errors()) return; va_start(args, fmt); - vsnprintf(buf, sizeof(buf), fmt, args); + __slab_bug(s, fmt, args); va_end(args); - slab_bug(s, "%s", buf); + __slab_err(slab); } @@ -1185,7 +1193,7 @@ static void init_object(struct kmem_cache *s, void *object, u8 val) s->inuse - poison_size); } -static void restore_bytes(struct kmem_cache *s, char *message, u8 data, +static void restore_bytes(struct kmem_cache *s, const char *message, u8 data, void *from, void *to) { slab_fix(s, "Restoring %s 0x%p-0x%p=0x%x", message, from, to - 1, data); @@ -1200,7 +1208,7 @@ static void restore_bytes(struct kmem_cache *s, char *message, u8 data, static pad_check_attributes int check_bytes_and_report(struct kmem_cache *s, struct slab *slab, - u8 *object, char *what, u8 *start, unsigned int value, + u8 *object, const char *what, u8 *start, unsigned int value, unsigned int bytes, bool slab_obj_print) { u8 *fault; -- 2.51.0