| 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 */ |