From 5ec8a847bb8ae2ba6395cfb7cb4bfdc78ada82ed Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 1 Feb 2006 03:05:44 -0800 Subject: [PATCH] [PATCH] slab: have index_of bug at compile time I noticed the code for index_of is a creative way of finding the cache index using the compiler to optimize to a single hard coded number. But I couldn't help noticing that it uses two methods to let you know that someone used it wrong. One is at compile time (the correct way), and the other is at run time (not good). Signed-off-by: Steven Rostedt Acked-by: Manfred Spraul Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index bb7a9837b9..613d385519 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -316,6 +316,8 @@ struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; */ static __always_inline int index_of(const size_t size) { + extern void __bad_size(void); + if (__builtin_constant_p(size)) { int i = 0; @@ -326,12 +328,9 @@ static __always_inline int index_of(const size_t size) i++; #include "linux/kmalloc_sizes.h" #undef CACHE - { - extern void __bad_size(void); - __bad_size(); - } + __bad_size(); } else - BUG(); + __bad_size(); return 0; } -- 2.39.5