mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-04-24 10:49:54 +02:00
Heiko Carstens
6e83f167bb
commit26701574ceupstream. The futex operation FUTEX_OP_ANDN is supposed to implement *(int *)UADDR2 &= ~OPARG; The s390 implementation just implements an AND instead of ANDN. Add the missing bitwise not operation to oparg to fix this. This is broken since nearly 19 years, so it looks like user space is not making use of this operation. Fixes:3363fbdd6f("[PATCH] s390: futex atomic operations") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_S390_FUTEX_H
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#define _ASM_S390_FUTEX_H
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#include <linux/uaccess.h>
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#include <linux/futex.h>
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#include <asm/asm-extable.h>
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#include <asm/mmu_context.h>
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#include <asm/errno.h>
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#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
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asm volatile( \
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" sacf 256\n" \
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"0: l %1,0(%6)\n" \
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"1:"insn \
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"2: cs %1,%2,0(%6)\n" \
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"3: jl 1b\n" \
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" lhi %0,0\n" \
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"4: sacf 768\n" \
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EX_TABLE(0b,4b) EX_TABLE(1b,4b) \
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EX_TABLE(2b,4b) EX_TABLE(3b,4b) \
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: "=d" (ret), "=&d" (oldval), "=&d" (newval), \
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"=m" (*uaddr) \
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: "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
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"m" (*uaddr) : "cc");
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static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
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u32 __user *uaddr)
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{
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int oldval = 0, newval, ret;
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switch (op) {
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case FUTEX_OP_SET:
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__futex_atomic_op("lr %2,%5\n",
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ret, oldval, newval, uaddr, oparg);
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break;
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case FUTEX_OP_ADD:
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__futex_atomic_op("lr %2,%1\nar %2,%5\n",
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ret, oldval, newval, uaddr, oparg);
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break;
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case FUTEX_OP_OR:
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__futex_atomic_op("lr %2,%1\nor %2,%5\n",
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ret, oldval, newval, uaddr, oparg);
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break;
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case FUTEX_OP_ANDN:
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__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
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ret, oldval, newval, uaddr, ~oparg);
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break;
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case FUTEX_OP_XOR:
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__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
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ret, oldval, newval, uaddr, oparg);
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break;
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default:
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ret = -ENOSYS;
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}
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if (!ret)
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*oval = oldval;
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return ret;
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}
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static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
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u32 oldval, u32 newval)
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{
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int ret;
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asm volatile(
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" sacf 256\n"
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"0: cs %1,%4,0(%5)\n"
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"1: la %0,0\n"
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"2: sacf 768\n"
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EX_TABLE(0b,2b) EX_TABLE(1b,2b)
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: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
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: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
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: "cc", "memory");
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*uval = oldval;
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return ret;
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}
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#endif /* _ASM_S390_FUTEX_H */
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