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| author |   Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2019-12-04 02:06:23 +0100 |
|---|---|---|
| committer |   Dennis Zhou <dennis@kernel.org> | 2020-01-31 11:15:59 -0800 |
| commit | becef184dfe9bfef522c80501d22a5e02efba8d8 (patch) | |
| tree | c87e1932bc76722b1bb01ec0f4de81e6af106d3b /include/asm-generic/percpu.h | |
| parent | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm (diff) | |
| download | linux-dev-becef184dfe9bfef522c80501d22a5e02efba8d8.tar.xz linux-dev-becef184dfe9bfef522c80501d22a5e02efba8d8.zip | |
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.h | 10 |
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; \ |