#ifndef _ASM_X86_FUTEX_H #define _ASM_X86_FUTEX_H #ifdef __KERNEL__ #include <linux/futex.h> #include <linux/uaccess.h> #include <asm/asm.h> #include <asm/errno.h> #include <asm/processor.h> #include <asm/system.h> #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \ asm volatile("1:\t" insn "\n" \ "2:\t.section .fixup,\"ax\"\n" \ "3:\tmov\t%3, %1\n" \ "\tjmp\t2b\n" \ "\t.previous\n" \ _ASM_EXTABLE(1b, 3b) \ : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \ : "i" (-EFAULT), "0" (oparg), "1" (0)) #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \ asm volatile("1:\tmovl %2, %0\n" \ "\tmovl\t%0, %3\n" \ "\t" insn "\n" \ "2:\tlock; cmpxchgl %3, %2\n" \ "\tjnz\t1b\n" \ "3:\t.section .fixup,\"ax\"\n" \ "4:\tmov\t%5, %1\n" \ "\tjmp\t3b\n" \ "\t.previous\n" \ _ASM_EXTABLE(1b, 4b) \ _ASM_EXTABLE(2b, 4b) \ : "=&a" (oldval), "=&r" (ret), \ "+m" (*uaddr), "=&r" (tem) \ : "r" (oparg), "i" (-EFAULT), "1" (0)) static inline int futex_atomic_op_inuser(int encoded_op, int __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, tem; if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) /* Real i386 machines can only support FUTEX_OP_SET */ if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3) return -ENOSYS; #endif pagefault_disable(); switch (op) { case FUTEX_OP_SET: __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); break; case FUTEX_OP_ADD: __futex_atomic_op1("lock; xaddl %0, %2", ret, oldval, uaddr, oparg); break; case FUTEX_OP_OR: __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg); break; case FUTEX_OP_ANDN: __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg); break; case FUTEX_OP_XOR: __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg); break; 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(int __user *uaddr, int oldval, int newval) { #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) /* Real i386 machines have no cmpxchg instruction */ if (boot_cpu_data.x86 == 3) return -ENOSYS; #endif if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; asm volatile("1:\tlock; cmpxchgl %3, %1\n" "2:\t.section .fixup, \"ax\"\n" "3:\tmov %2, %0\n" "\tjmp 2b\n" "\t.previous\n" _ASM_EXTABLE(1b, 3b) : "=a" (oldval), "+m" (*uaddr) : "i" (-EFAULT), "r" (newval), "0" (oldval) : "memory" ); return oldval; } #endif #endif