1 #ifndef _ASM_X86_FUTEX_H 2 #define _ASM_X86_FUTEX_H 3 4 #ifdef __KERNEL__ 5 6 #include <linux/futex.h> 7 #include <linux/uaccess.h> 8 9 #include <asm/asm.h> 10 #include <asm/errno.h> 11 #include <asm/processor.h> 12 #include <asm/smap.h> 13 14 #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \ 15 asm volatile("\t" ASM_STAC "\n" \ 16 "1:\t" insn "\n" \ 17 "2:\t" ASM_CLAC "\n" \ 18 "\t.section .fixup,\"ax\"\n" \ 19 "3:\tmov\t%3, %1\n" \ 20 "\tjmp\t2b\n" \ 21 "\t.previous\n" \ 22 _ASM_EXTABLE(1b, 3b) \ 23 : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \ 24 : "i" (-EFAULT), "0" (oparg), "1" (0)) 25 26 #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \ 27 asm volatile("\t" ASM_STAC "\n" \ 28 "1:\tmovl %2, %0\n" \ 29 "\tmovl\t%0, %3\n" \ 30 "\t" insn "\n" \ 31 "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \ 32 "\tjnz\t1b\n" \ 33 "3:\t" ASM_CLAC "\n" \ 34 "\t.section .fixup,\"ax\"\n" \ 35 "4:\tmov\t%5, %1\n" \ 36 "\tjmp\t3b\n" \ 37 "\t.previous\n" \ 38 _ASM_EXTABLE(1b, 4b) \ 39 _ASM_EXTABLE(2b, 4b) \ 40 : "=&a" (oldval), "=&r" (ret), \ 41 "+m" (*uaddr), "=&r" (tem) \ 42 : "r" (oparg), "i" (-EFAULT), "1" (0)) 43 44 static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) 45 { 46 int op = (encoded_op >> 28) & 7; 47 int cmp = (encoded_op >> 24) & 15; 48 int oparg = (encoded_op << 8) >> 20; 49 int cmparg = (encoded_op << 20) >> 20; 50 int oldval = 0, ret, tem; 51 52 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) 53 oparg = 1 << oparg; 54 55 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) 56 return -EFAULT; 57 58 pagefault_disable(); 59 60 switch (op) { 61 case FUTEX_OP_SET: 62 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); 63 break; 64 case FUTEX_OP_ADD: 65 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval, 66 uaddr, oparg); 67 break; 68 case FUTEX_OP_OR: 69 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg); 70 break; 71 case FUTEX_OP_ANDN: 72 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg); 73 break; 74 case FUTEX_OP_XOR: 75 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg); 76 break; 77 default: 78 ret = -ENOSYS; 79 } 80 81 pagefault_enable(); 82 83 if (!ret) { 84 switch (cmp) { 85 case FUTEX_OP_CMP_EQ: 86 ret = (oldval == cmparg); 87 break; 88 case FUTEX_OP_CMP_NE: 89 ret = (oldval != cmparg); 90 break; 91 case FUTEX_OP_CMP_LT: 92 ret = (oldval < cmparg); 93 break; 94 case FUTEX_OP_CMP_GE: 95 ret = (oldval >= cmparg); 96 break; 97 case FUTEX_OP_CMP_LE: 98 ret = (oldval <= cmparg); 99 break; 100 case FUTEX_OP_CMP_GT: 101 ret = (oldval > cmparg); 102 break; 103 default: 104 ret = -ENOSYS; 105 } 106 } 107 return ret; 108 } 109 110 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 111 u32 oldval, u32 newval) 112 { 113 return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval); 114 } 115 116 #endif 117 #endif /* _ASM_X86_FUTEX_H */ 118