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| author | Max Filippov <jcmvbkbc@gmail.com> | 2018-01-05 14:27:58 -0800 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2018-01-05 15:55:59 -0800 |
| commit | ca47480921587ae30417dd234a9f79af188e3666 (patch) | |
| tree | 8855c77493e9a06d7915d83fb2add249f693572c | |
| parent | 32bb954dbf6db98562cb4477608dc546421caaf6 (diff) | |
| download | linux-ca47480921587ae30417dd234a9f79af188e3666.tar.bz2 | |
xtensa: fix futex_atomic_cmpxchg_inatomic
Return 0 if the operation was successful, not the userspace memory
value. Check that userspace value equals passed oldval, not itself.
Don't update *uval if the value wasn't read from userspace memory.
This fixes process hang due to infinite loop in futex_lock_pi.
It also fixes a bunch of glibc tests nptl/tst-mutexpi*.
Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
| -rw-r--r-- | arch/xtensa/include/asm/futex.h | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/arch/xtensa/include/asm/futex.h b/arch/xtensa/include/asm/futex.h index eaaf1ebcc7a4..5bfbc1c401d4 100644 --- a/arch/xtensa/include/asm/futex.h +++ b/arch/xtensa/include/asm/futex.h @@ -92,7 +92,6 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { int ret = 0; - u32 prev; if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; @@ -103,26 +102,24 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, __asm__ __volatile__ ( " # futex_atomic_cmpxchg_inatomic\n" - "1: l32i %1, %3, 0\n" - " mov %0, %5\n" - " wsr %1, scompare1\n" - "2: s32c1i %0, %3, 0\n" - "3:\n" + " wsr %5, scompare1\n" + "1: s32c1i %1, %4, 0\n" + " s32i %1, %6, 0\n" + "2:\n" " .section .fixup,\"ax\"\n" " .align 4\n" - "4: .long 3b\n" - "5: l32r %1, 4b\n" - " movi %0, %6\n" + "3: .long 2b\n" + "4: l32r %1, 3b\n" + " movi %0, %7\n" " jx %1\n" " .previous\n" " .section __ex_table,\"a\"\n" - " .long 1b,5b,2b,5b\n" + " .long 1b,4b\n" " .previous\n" - : "+r" (ret), "=&r" (prev), "+m" (*uaddr) - : "r" (uaddr), "r" (oldval), "r" (newval), "I" (-EFAULT) + : "+r" (ret), "+r" (newval), "+m" (*uaddr), "+m" (*uval) + : "r" (uaddr), "r" (oldval), "r" (uval), "I" (-EFAULT) : "memory"); - *uval = prev; return ret; } |