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[PATCH] s390: fix in-user atomic futex operation.

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From: Martin Schwidefsky <schwidefsky@de.ibm.com>

__futex_atomic_op needs to do an atomic operation in the user address space,
not the kernel address space.  Add the missing sacf 256/sacf 0 to switch to
the secondary mode before doing the compare-and-swap.  In addition add
another fixup for catch specification exceptions if the compare-and-swap
address is not aligned.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Martin Schwidefsky 2006-06-08 01:36:20 -07:00 committed by Linus Torvalds
parent 71601e2b33
commit bafe00cc92
1 changed files with 8 additions and 7 deletions
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15
include/asm-s390/futex.h
View file

@ -11,23 +11,24 @@
#define __futex_atomic_fixup \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 0b,2b,1b,2b\n" \
" .long 0b,4b,2b,4b,3b,4b\n" \
".previous"
#else /* __s390x__ */
#define __futex_atomic_fixup \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
" .quad 0b,2b,1b,2b\n" \
" .quad 0b,4b,2b,4b,3b,4b\n" \
".previous"
#endif /* __s390x__ */
#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
asm volatile(" l %1,0(%6)\n" \
"0: " insn \
" cs %1,%2,0(%6)\n" \
"1: jl 0b\n" \
asm volatile(" sacf 256\n" \
"0: l %1,0(%6)\n" \
"1: " insn \
"2: cs %1,%2,0(%6)\n" \
"3: jl 1b\n" \
" lhi %0,0\n" \
"2:\n" \
"4: sacf 0\n" \
__futex_atomic_fixup \
: "=d" (ret), "=&d" (oldval), "=&d" (newval), \
"=m" (*uaddr) \