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| author | Jan Blunck <jblunck@suse.de> | 2006-09-25 23:30:53 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:44 -0700 |
| commit | 632bbfeee4f042c05bc65150b4433a297d3fe387 (patch) | |
| tree | ce67b5fa4bec38610fc0ecb9b20be6aa69763bb3 | |
| parent | 0a2966b48fb784e437520e400ddc94874ddbd4e8 (diff) | |
| download | linux-632bbfeee4f042c05bc65150b4433a297d3fe387.tar.gz | |
[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 <jblunck@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/asm-generic/percpu.h | 4 | ||||
| -rw-r--r-- | include/asm-s390/percpu.h | 20 | ||||
| -rw-r--r-- | include/asm-x86_64/percpu.h | 12 | ||||
| -rw-r--r-- | include/linux/percpu.h | 10 |
4 files changed, 31 insertions, 15 deletions
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index e160e04290fb9..6d45ee5472aff 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -14,7 +14,9 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name /* var is in discarded region: offset to particular copy we want */ -#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu])) +#define per_cpu(var, cpu) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); })) #define __get_cpu_var(var) per_cpu(var, smp_processor_id()) #define __raw_get_cpu_var(var) per_cpu(var, raw_smp_processor_id()) diff --git a/include/asm-s390/percpu.h b/include/asm-s390/percpu.h index 28b3517e787cd..495ad99c76351 100644 --- a/include/asm-s390/percpu.h +++ b/include/asm-s390/percpu.h @@ -15,18 +15,20 @@ */ #if defined(__s390x__) && defined(MODULE) -#define __reloc_hide(var,offset) \ - (*({ unsigned long *__ptr; \ - asm ( "larl %0,per_cpu__"#var"@GOTENT" \ - : "=a" (__ptr) : "X" (per_cpu__##var) ); \ - (typeof(&per_cpu__##var))((*__ptr) + (offset)); })) +#define __reloc_hide(var,offset) (*({ \ + extern int simple_indentifier_##var(void); \ + unsigned long *__ptr; \ + asm ( "larl %0,per_cpu__"#var"@GOTENT" \ + : "=a" (__ptr) : "X" (per_cpu__##var) ); \ + (typeof(&per_cpu__##var))((*__ptr) + (offset)); })) #else -#define __reloc_hide(var, offset) \ - (*({ unsigned long __ptr; \ - asm ( "" : "=a" (__ptr) : "0" (&per_cpu__##var) ); \ - (typeof(&per_cpu__##var)) (__ptr + (offset)); })) +#define __reloc_hide(var, offset) (*({ \ + extern int simple_indentifier_##var(void); \ + unsigned long __ptr; \ + asm ( "" : "=a" (__ptr) : "0" (&per_cpu__##var) ); \ + (typeof(&per_cpu__##var)) (__ptr + (offset)); })) #endif diff --git a/include/asm-x86_64/percpu.h b/include/asm-x86_64/percpu.h index 08dd9f9dda818..bffb2f886a510 100644 --- a/include/asm-x86_64/percpu.h +++ b/include/asm-x86_64/percpu.h @@ -21,9 +21,15 @@ __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name /* var is in discarded region: offset to particular copy we want */ -#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu))) -#define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset())) -#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset())) +#define per_cpu(var, cpu) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)); })) +#define __get_cpu_var(var) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); })) +#define __raw_get_cpu_var(var) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); })) /* A macro to avoid #include hell... */ #define percpu_modcopy(pcpudst, src, size) \ diff --git a/include/linux/percpu.h b/include/linux/percpu.h index cb9039a21f2a7..f926490a7d8ba 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 |