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870779f40e
Use user_access_begin() instead of the access_ok/allow_access sequence. This brings the missing might_fault() check. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6cd202cdc4f939d47822e4ddd3c0856210431a58.1615398498.git.christophe.leroy@csgroup.eu
101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_FUTEX_H
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#define _ASM_POWERPC_FUTEX_H
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#ifdef __KERNEL__
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#include <linux/futex.h>
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#include <linux/uaccess.h>
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#include <asm/errno.h>
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#include <asm/synch.h>
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#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
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__asm__ __volatile ( \
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PPC_ATOMIC_ENTRY_BARRIER \
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"1: lwarx %0,0,%2\n" \
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insn \
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"2: stwcx. %1,0,%2\n" \
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"bne- 1b\n" \
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PPC_ATOMIC_EXIT_BARRIER \
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"li %1,0\n" \
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"3: .section .fixup,\"ax\"\n" \
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"4: li %1,%3\n" \
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"b 3b\n" \
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".previous\n" \
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EX_TABLE(1b, 4b) \
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EX_TABLE(2b, 4b) \
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: "=&r" (oldval), "=&r" (ret) \
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: "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
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: "cr0", "memory")
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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, ret;
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if (!user_access_begin(uaddr, sizeof(u32)))
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return -EFAULT;
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switch (op) {
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case FUTEX_OP_SET:
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__futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_ADD:
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__futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_OR:
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__futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_ANDN:
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__futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_XOR:
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__futex_atomic_op("xor %1,%0,%4\n", ret, oldval, 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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user_access_end();
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*oval = oldval;
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return ret;
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}
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static inline int
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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 = 0;
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u32 prev;
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if (!user_access_begin(uaddr, sizeof(u32)))
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return -EFAULT;
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__asm__ __volatile__ (
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PPC_ATOMIC_ENTRY_BARRIER
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"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
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cmpw 0,%1,%4\n\
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bne- 3f\n"
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"2: stwcx. %5,0,%3\n\
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bne- 1b\n"
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PPC_ATOMIC_EXIT_BARRIER
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"3: .section .fixup,\"ax\"\n\
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4: li %0,%6\n\
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b 3b\n\
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.previous\n"
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EX_TABLE(1b, 4b)
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EX_TABLE(2b, 4b)
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: "+r" (ret), "=&r" (prev), "+m" (*uaddr)
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: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
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: "cc", "memory");
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user_access_end();
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*uval = prev;
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return ret;
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}
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_FUTEX_H */
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