The patch titled
Subject: ia64: fix sparse warnings with cmpxchg() & xchg()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
ia64-fix-sparse-warnings-with-cmpxchg-xchg.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ia64-fix-sparse-warnings-with-cmpxchg-xchg.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
Subject: ia64: fix sparse warnings with cmpxchg() & xchg()
Date: Sun, 5 Jun 2022 18:07:38 +0200
On IA64, new sparse's warnings where issued after fixing some __rcu
annotations in kernel/bpf/.
These new warnings are false positives and appear on IA64 because on this
architecture, the macros for cmpxchg() and xchg() make casts that ignore
sparse annotations.
This patch contains the minimal patch to fix this issue: adding a missing
cast and some missing '__force'.
Link: https://lore.kernel.org/r/20220601120013.bq5a3ynbkc3hngm5@mail
Link: https://lkml.kernel.org/r/20220605160738.79736-1-luc.vanoostenryck@xxxxxxxxx
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/ia64/include/uapi/asm/cmpxchg.h | 28 ++++++++++++-------------
1 file changed, 14 insertions(+), 14 deletions(-)
--- a/arch/ia64/include/uapi/asm/cmpxchg.h~ia64-fix-sparse-warnings-with-cmpxchg-xchg
+++ a/arch/ia64/include/uapi/asm/cmpxchg.h
@@ -33,24 +33,24 @@ extern void ia64_xchg_called_with_bad_po
\
switch (size) { \
case 1: \
- __xchg_result = ia64_xchg1((__u8 *)ptr, x); \
+ __xchg_result = ia64_xchg1((__u8 __force *)ptr, x); \
break; \
\
case 2: \
- __xchg_result = ia64_xchg2((__u16 *)ptr, x); \
+ __xchg_result = ia64_xchg2((__u16 __force *)ptr, x); \
break; \
\
case 4: \
- __xchg_result = ia64_xchg4((__u32 *)ptr, x); \
+ __xchg_result = ia64_xchg4((__u32 __force *)ptr, x); \
break; \
\
case 8: \
- __xchg_result = ia64_xchg8((__u64 *)ptr, x); \
+ __xchg_result = ia64_xchg8((__u64 __force *)ptr, x); \
break; \
default: \
ia64_xchg_called_with_bad_pointer(); \
} \
- __xchg_result; \
+ (__typeof__ (*(ptr)) __force) __xchg_result; \
})
#ifndef __KERNEL__
@@ -76,42 +76,42 @@ extern long ia64_cmpxchg_called_with_bad
\
switch (size) { \
case 1: \
- _o_ = (__u8) (long) (old); \
+ _o_ = (__u8) (long __force) (old); \
break; \
case 2: \
- _o_ = (__u16) (long) (old); \
+ _o_ = (__u16) (long __force) (old); \
break; \
case 4: \
- _o_ = (__u32) (long) (old); \
+ _o_ = (__u32) (long __force) (old); \
break; \
case 8: \
- _o_ = (__u64) (long) (old); \
+ _o_ = (__u64) (long __force) (old); \
break; \
default: \
break; \
} \
switch (size) { \
case 1: \
- _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \
+ _r_ = ia64_cmpxchg1_##sem((__u8 __force *) ptr, new, _o_); \
break; \
\
case 2: \
- _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \
+ _r_ = ia64_cmpxchg2_##sem((__u16 __force *) ptr, new, _o_); \
break; \
\
case 4: \
- _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \
+ _r_ = ia64_cmpxchg4_##sem((__u32 __force *) ptr, new, _o_); \
break; \
\
case 8: \
- _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \
+ _r_ = ia64_cmpxchg8_##sem((__u64 __force *) ptr, new, _o_); \
break; \
\
default: \
_r_ = ia64_cmpxchg_called_with_bad_pointer(); \
break; \
} \
- (__typeof__(old)) _r_; \
+ (__typeof__(old) __force) _r_; \
})
#define cmpxchg_acq(ptr, o, n) \
_
Patches currently in -mm which might be from luc.vanoostenryck@xxxxxxxxx are
ia64-fix-sparse-warnings-with-cmpxchg-xchg.patch
