From 632bbfeee4f042c05bc65150b4433a297d3fe387 Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Mon, 25 Sep 2006 23:30:53 -0700 Subject: [PATCH] trigger a syntax error if percpu macros are incorrectly used get_cpu_var()/per_cpu()/__get_cpu_var() arguments must be simple identifiers. Otherwise the arch dependent implementations might break. This patch enforces the correct usage of the macros by producing a syntax error if the variable is not a simple identifier. Signed-off-by: Jan Blunck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/percpu.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/percpu.h b/include/linux/percpu.h index cb9039a21f2..f926490a7d8 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -11,8 +11,14 @@ #define PERCPU_ENOUGH_ROOM 32768 #endif -/* Must be an lvalue. */ -#define get_cpu_var(var) (*({ preempt_disable(); &__get_cpu_var(var); })) +/* + * Must be an lvalue. Since @var must be a simple identifier, + * we force a syntax error here if it isn't. + */ +#define get_cpu_var(var) (*({ \ + extern int simple_indentifier_##var(void); \ + preempt_disable(); \ + &__get_cpu_var(var); })) #define put_cpu_var(var) preempt_enable() #ifdef CONFIG_SMP -- cgit v1.2.3