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authorWill Deacon <will.deacon@arm.com>2018-08-30 13:52:38 -0700
committerVineet Gupta <vgupta@synopsys.com>2018-08-31 10:14:51 -0700
commit3fcbb8260a87efb691d837e8cd24e81f65b3eb70 (patch)
tree27e20e28bb09a587b76609799c0410b37e1d0d8c /arch/arc
parent2b52e2a67c86b0714eeae0d2030cb7fc14737626 (diff)
ARC: atomics: unbork atomic_fetch_##op()
In 4.19-rc1, Eugeniy reported weird boot and IO errors on ARC HSDK | INFO: task syslogd:77 blocked for more than 10 seconds. | Not tainted 4.19.0-rc1-00007-gf213acea4e88 #40 | "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this | message. | syslogd D 0 77 76 0x00000000 | | Stack Trace: | __switch_to+0x0/0xac | __schedule+0x1b2/0x730 | io_schedule+0x5c/0xc0 | __lock_page+0x98/0xdc | find_lock_entry+0x38/0x100 | shmem_getpage_gfp.isra.3+0x82/0xbfc | shmem_fault+0x46/0x138 | handle_mm_fault+0x5bc/0x924 | do_page_fault+0x100/0x2b8 | ret_from_exception+0x0/0x8 He bisected to 84c6591103db ("locking/atomics, asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*()") This commit however only unmasked the real issue introduced by commit 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") which missed the retry-if-scond-failed branch in atomic_fetch_##op() macros. The bisected commit started using atomic_fetch_##op() macros for building the rest of atomics. Fixes: 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") Reported-by: Eugeniy Paltsev <paltsev@synopsys.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: wrote changelog]
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/include/asm/atomic.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index 4e0072730241..158af079838d 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -84,7 +84,7 @@ static inline int atomic_fetch_##op(int i, atomic_t *v) \
"1: llock %[orig], [%[ctr]] \n" \
" " #asm_op " %[val], %[orig], %[i] \n" \
" scond %[val], [%[ctr]] \n" \
- " \n" \
+ " bnz 1b \n" \
: [val] "=&r" (val), \
[orig] "=&r" (orig) \
: [ctr] "r" (&v->counter), \