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authorLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2019-12-04 02:06:23 +0100
committerDennis Zhou <dennis@kernel.org>2020-01-31 11:15:59 -0800
commitbecef184dfe9bfef522c80501d22a5e02efba8d8 (patch)
treec87e1932bc76722b1bb01ec0f4de81e6af106d3b /include/asm-generic/percpu.h
parentaedc0650f9135f3b92b39cbed1a8fe98d8088825 (diff)
percpu: fix __percpu annotation in asm-generic
The generic implementation of raw_cpu_generic_add_return() is: #define raw_cpu_generic_add_return(pcp, val) \ ({ \ typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \ \ *__p += val; \ *__p; \ }) where the 'pcp' argument is a __percpu lvalue. There, the variable '__p' is declared as a __percpu pointer the type of the address of 'pcp') but: 1) the value assigned to it, the return value of raw_cpu_ptr(), is a plain (__kernel) pointer, not a __percpu one. 2) this variable is dereferenced just after while a __percpu pointer is implicitly __noderef. So, fix the declaration of the 'pcp' variable to its correct type: the plain (non-percpu) pointer corresponding to pcp's address, using the fact that typeof() ignores the address space and the 'noderef' attribute of its agument. Same for raw_cpu_generic_xchg(), raw_cpu_generic_cmpxchg() & raw_cpu_generic_cmpxchg_double(). This removes 209 warnings on ARM, 525 on ARM64, 220 on x86 & more than 2600 on ppc64 (all of them with the default config). Cc: Tejun Heo <tj@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Reported-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Dennis Zhou <dennis@kernel.org>
Diffstat (limited to 'include/asm-generic/percpu.h')
-rw-r--r--include/asm-generic/percpu.h10
1 files changed, 5 insertions, 5 deletions
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index c2de013b2cf4..35e4a53b83e6 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -74,7 +74,7 @@ do { \
#define raw_cpu_generic_add_return(pcp, val) \
({ \
- typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \
+ typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \
\
*__p += val; \
*__p; \
@@ -82,7 +82,7 @@ do { \
#define raw_cpu_generic_xchg(pcp, nval) \
({ \
- typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \
+ typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \
typeof(pcp) __ret; \
__ret = *__p; \
*__p = nval; \
@@ -91,7 +91,7 @@ do { \
#define raw_cpu_generic_cmpxchg(pcp, oval, nval) \
({ \
- typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \
+ typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \
typeof(pcp) __ret; \
__ret = *__p; \
if (__ret == (oval)) \
@@ -101,8 +101,8 @@ do { \
#define raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
({ \
- typeof(&(pcp1)) __p1 = raw_cpu_ptr(&(pcp1)); \
- typeof(&(pcp2)) __p2 = raw_cpu_ptr(&(pcp2)); \
+ typeof(pcp1) *__p1 = raw_cpu_ptr(&(pcp1)); \
+ typeof(pcp2) *__p2 = raw_cpu_ptr(&(pcp2)); \
int __ret = 0; \
if (*__p1 == (oval1) && *__p2 == (oval2)) { \
*__p1 = nval1; \