forked from Minki/linux
0f09c27469
Naresh reported another architecture that was broken by the same typo that was already fixed for three architectures: mips also refers to the futex_atomic_op_inuser_local() function by the wrong name and runs into a missing closing '}' as well. Going through the source tree the same typo was found in the documentation as well as in the xtensa code, both of which ended up escaping the regression testing so far. In the case of xtensa, it appears that the broken code path is only used when building for platforms that are not supported by the default gcc configuration, so they are impossible to test for with default setups. After going through these more carefully and fixing up the typos, all architectures have been build-tested again to ensure that this is now complete. Fixes:4e0d846344("futex: Fix sparc32/m68k/nds32 build regression") Fixes:3f2bedabb6("futex: Ensure futex_atomic_cmpxchg_inatomic() is present") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20211203080823.2938839-1-arnd@kernel.org
122 lines
2.6 KiB
C
122 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_GENERIC_FUTEX_H
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#define _ASM_GENERIC_FUTEX_H
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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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#ifndef futex_atomic_cmpxchg_inatomic
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#ifndef CONFIG_SMP
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/*
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* The following implementation only for uniprocessor machines.
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* It relies on preempt_disable() ensuring mutual exclusion.
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*
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*/
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#define futex_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval) \
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futex_atomic_cmpxchg_inatomic_local(uval, uaddr, oldval, newval)
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#define arch_futex_atomic_op_inuser(op, oparg, oval, uaddr) \
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futex_atomic_op_inuser_local(op, oparg, oval, uaddr)
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#endif /* CONFIG_SMP */
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#endif
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/**
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* futex_atomic_op_inuser_local() - Atomic arithmetic operation with constant
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* argument and comparison of the previous
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* futex value with another constant.
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*
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* @encoded_op: encoded operation to execute
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* @uaddr: pointer to user space address
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*
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* Return:
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* 0 - On success
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* -EFAULT - User access resulted in a page fault
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* -EAGAIN - Atomic operation was unable to complete due to contention
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* -ENOSYS - Operation not supported
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*/
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static inline int
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futex_atomic_op_inuser_local(int op, u32 oparg, int *oval, u32 __user *uaddr)
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{
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int oldval, ret;
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u32 tmp;
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preempt_disable();
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ret = -EFAULT;
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if (unlikely(get_user(oldval, uaddr) != 0))
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goto out_pagefault_enable;
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ret = 0;
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tmp = oldval;
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switch (op) {
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case FUTEX_OP_SET:
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tmp = oparg;
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break;
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case FUTEX_OP_ADD:
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tmp += oparg;
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break;
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case FUTEX_OP_OR:
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tmp |= oparg;
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break;
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case FUTEX_OP_ANDN:
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tmp &= ~oparg;
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break;
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case FUTEX_OP_XOR:
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tmp ^= 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 == 0 && unlikely(put_user(tmp, uaddr) != 0))
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ret = -EFAULT;
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out_pagefault_enable:
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preempt_enable();
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if (ret == 0)
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*oval = oldval;
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return ret;
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}
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/**
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* futex_atomic_cmpxchg_inatomic_local() - Compare and exchange the content of the
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* uaddr with newval if the current value is
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* oldval.
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* @uval: pointer to store content of @uaddr
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* @uaddr: pointer to user space address
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* @oldval: old value
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* @newval: new value to store to @uaddr
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*
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* Return:
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* 0 - On success
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* -EFAULT - User access resulted in a page fault
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* -EAGAIN - Atomic operation was unable to complete due to contention
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*/
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static inline int
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futex_atomic_cmpxchg_inatomic_local(u32 *uval, u32 __user *uaddr,
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u32 oldval, u32 newval)
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{
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u32 val;
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preempt_disable();
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if (unlikely(get_user(val, uaddr) != 0)) {
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preempt_enable();
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return -EFAULT;
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}
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if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) {
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preempt_enable();
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return -EFAULT;
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}
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*uval = val;
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preempt_enable();
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return 0;
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}
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#endif
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