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| author | Max Filippov <jcmvbkbc@gmail.com> | 2014-07-31 20:40:57 +0200 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2014-08-14 09:59:31 +0200 |
| commit | d1b6ba82a50cecf94be540a3a153aa89d97511a0 (patch) | |
| tree | 4e77c4cc78304f8253bd56da69bada62b08e8717 /arch/xtensa/kernel/entry.S | |
| parent | xtensa: allow single-stepping through unaligned load/store (diff) | |
| download | linux-d1b6ba82a50cecf94be540a3a153aa89d97511a0.tar.xz linux-d1b6ba82a50cecf94be540a3a153aa89d97511a0.zip | |
xtensa: fix a6 and a7 handling in fast_syscall_xtensa
Remove restoring a6 on some return paths and instead modify and restore
it in a single place, using symbolic name.
Correctly restore a7 from PT_AREG7 in case of illegal a6 value.
Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 21917e5fd53a..a06b7efaae82 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1001,9 +1001,8 @@ ENTRY(fast_syscall_xtensa) movi a7, 4 # sizeof(unsigned int) access_ok a3, a7, a0, a2, .Leac # a0: scratch reg, a2: sp - addi a6, a6, -1 # assuming SYS_XTENSA_ATOMIC_SET = 1 - _bgeui a6, SYS_XTENSA_COUNT - 1, .Lill - _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP - 1, .Lnswp + _bgeui a6, SYS_XTENSA_COUNT, .Lill + _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP, .Lnswp /* Fall through for ATOMIC_CMP_SWP. */ @@ -1015,27 +1014,26 @@ TRY s32i a5, a3, 0 # different, modify value l32i a7, a2, PT_AREG7 # restore a7 l32i a0, a2, PT_AREG0 # restore a0 movi a2, 1 # and return 1 - addi a6, a6, 1 # restore a6 (really necessary?) rfe 1: l32i a7, a2, PT_AREG7 # restore a7 l32i a0, a2, PT_AREG0 # restore a0 movi a2, 0 # return 0 (note that we cannot set - addi a6, a6, 1 # restore a6 (really necessary?) rfe .Lnswp: /* Atomic set, add, and exg_add. */ TRY l32i a7, a3, 0 # orig + addi a6, a6, -SYS_XTENSA_ATOMIC_SET add a0, a4, a7 # + arg moveqz a0, a4, a6 # set + addi a6, a6, SYS_XTENSA_ATOMIC_SET TRY s32i a0, a3, 0 # write new value mov a0, a2 mov a2, a7 l32i a7, a0, PT_AREG7 # restore a7 l32i a0, a0, PT_AREG0 # restore a0 - addi a6, a6, 1 # restore a6 (really necessary?) rfe CATCH @@ -1044,7 +1042,7 @@ CATCH movi a2, -EFAULT rfe -.Lill: l32i a7, a2, PT_AREG0 # restore a7 +.Lill: l32i a7, a2, PT_AREG7 # restore a7 l32i a0, a2, PT_AREG0 # restore a0 movi a2, -EINVAL rfe |