[PATCH 5/6] driver core: Add __alloc_size hint to devm allocators

From: Kees Cook <keescook@chromium.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rasmus Villemoes <rasmus.villemoes@prevas.dk>,
	Thomas Gleixner <tglx@linutronix.de>,
	Jason Gunthorpe <jgg@ziepe.ca>, Nishanth Menon <nm@ti.com>,
	Michael Kelley <mikelley@microsoft.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Won Chung <wonchung@google.com>, David Gow <davidgow@google.com>,
	Christoph Lameter <cl@linux.com>,
	Pekka Enberg <penberg@kernel.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Roman Gushchin <roman.gushchin@linux.dev>,
	Hyeonggon Yoo <42.hyeyoo@gmail.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Andy Shevchenko <andriy.shevchenko@intel.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-hardening@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH 5/6] driver core: Add __alloc_size hint to devm allocators
Date: Tue,  1 Nov 2022 15:33:13 -0700	[thread overview]
Message-ID: <20221101223321.1326815-5-keescook@chromium.org> (raw)
In-Reply-To: <20221101222520.never.109-kees@kernel.org>

Mark the devm_*alloc()-family of allocations with appropriate
__alloc_size()/__realloc_size() hints so the compiler can attempt to
reason about buffer lengths from allocations.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Nishanth Menon <nm@ti.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Won Chung <wonchung@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20221029074734.gonna.276-kees@kernel.org
---
This is already in -next, but I'm including it here again to avoid any
confusion about this series landing (or being tested) via another tree.
---
 include/linux/device.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index 424b55df0272..5e4cd857e74f 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -197,9 +197,9 @@ void devres_remove_group(struct device *dev, void *id);
 int devres_release_group(struct device *dev, void *id);
 
 /* managed devm_k.alloc/kfree for device drivers */
-void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
+void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __alloc_size(2);
 void *devm_krealloc(struct device *dev, void *ptr, size_t size,
-		    gfp_t gfp) __must_check;
+		    gfp_t gfp) __must_check __realloc_size(3);
 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
 				     const char *fmt, va_list ap) __malloc;
 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
@@ -226,7 +226,8 @@ static inline void *devm_kcalloc(struct device *dev,
 void devm_kfree(struct device *dev, const void *p);
 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
-void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
+void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
+	__realloc_size(3);
 
 unsigned long devm_get_free_pages(struct device *dev,
 				  gfp_t gfp_mask, unsigned int order);
-- 
2.34.1

