percpu: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for
appropriate percpu allocator interfaces, to provide additional hinting for
better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other compiler
optimizations.

Link: https://lkml.kernel.org/r/20210818214021.2476230-7-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 5e76af742c807afd3630e630156ab7962c26acdb..119f41815b322fd1955aebe6fae81a925c9b3497 100644 (file)
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -123,6 +123,7 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
                                pcpu_fc_populate_pte_fn_t populate_pte_fn);
 #endif
 
+__alloc_size(1)
 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
 extern bool is_kernel_percpu_address(unsigned long addr);
@@ -131,7 +132,9 @@ extern bool is_kernel_percpu_address(unsigned long addr);
 extern void __init setup_per_cpu_areas(void);
 #endif
 
+__alloc_size(1)
 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
+__alloc_size(1)
 extern void __percpu *__alloc_percpu(size_t size, size_t align);
 extern void free_percpu(void __percpu *__pdata);
 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);