#ifndef _ASM_GENERIC_FUTEX_H #define _ASM_GENERIC_FUTEX_H #include #include #include #ifndef CONFIG_SMP /* * The following implementation only for uniprocessor machines. * It relies on preempt_disable() ensuring mutual exclusion. * */ /** * futex_atomic_op_inuser() - Atomic arithmetic operation with constant * argument and comparison of the previous * futex value with another constant. * * @encoded_op: encoded operation to execute * @uaddr: pointer to user space address * * Return: * 0 - On success * <0 - On error */ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; int oparg = (encoded_op << 8) >> 20; int cmparg = (encoded_op << 20) >> 20; int oldval, ret; u32 tmp; if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; preempt_disable(); pagefault_disable(); ret = -EFAULT; if (unlikely(get_user(oldval, uaddr) != 0)) goto out_pagefault_enable; ret = 0; tmp = oldval; switch (op) { case FUTEX_OP_SET: tmp = oparg; break; case FUTEX_OP_ADD: tmp += oparg; break; case FUTEX_OP_OR: tmp |= oparg; break; case FUTEX_OP_ANDN: tmp &= ~oparg; break; case FUTEX_OP_XOR: tmp ^= oparg; break; default: ret = -ENOSYS; } if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0)) ret = -EFAULT; out_pagefault_enable: pagefault_enable(); preempt_enable(); if (ret == 0) { switch (cmp) { case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; default: ret = -ENOSYS; } } return ret; } /** * futex_atomic_cmpxchg_inatomic() - Compare and exchange the content of the * uaddr with newval if the current value is * oldval. * @uval: pointer to store content of @uaddr * @uaddr: pointer to user space address * @oldval: old value * @newval: new value to store to @uaddr * * Return: * 0 - On success * <0 - On error */ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { u32 val; preempt_disable(); if (unlikely(get_user(val, uaddr) != 0)) { preempt_enable(); return -EFAULT; } if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) { preempt_enable(); return -EFAULT; } *uval = val; preempt_enable(); return 0; } #else static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; int oparg = (encoded_op << 8) >> 20; int cmparg = (encoded_op << 20) >> 20; int oldval = 0, ret; if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); switch (op) { case FUTEX_OP_SET: case FUTEX_OP_ADD: case FUTEX_OP_OR: case FUTEX_OP_ANDN: case FUTEX_OP_XOR: default: ret = -ENOSYS; } pagefault_enable(); if (!ret) { switch (cmp) { case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; default: ret = -ENOSYS; } } return ret; } static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { return -ENOSYS; } #endif /* CONFIG_SMP */ #endif option>space:mode:
Diffstat (limited to 'net/xfrm/xfrm_input.c')