cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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futex.h (2306B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _ASM_HEXAGON_FUTEX_H
      3#define _ASM_HEXAGON_FUTEX_H
      4
      5#ifdef __KERNEL__
      6
      7#include <linux/futex.h>
      8#include <linux/uaccess.h>
      9#include <asm/errno.h>
     10
     11/* XXX TODO-- need to add sync barriers! */
     12
     13#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
     14	__asm__ __volatile( \
     15	"1: %0 = memw_locked(%3);\n" \
     16	    /* For example: %1 = %4 */ \
     17	    insn \
     18	"2: memw_locked(%3,p2) = %1;\n" \
     19	"   if (!p2) jump 1b;\n" \
     20	"   %1 = #0;\n" \
     21	"3:\n" \
     22	".section .fixup,\"ax\"\n" \
     23	"4: %1 = #%5;\n" \
     24	"   jump ##3b\n" \
     25	".previous\n" \
     26	".section __ex_table,\"a\"\n" \
     27	".long 1b,4b,2b,4b\n" \
     28	".previous\n" \
     29	: "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
     30	: "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
     31	: "p2", "memory")
     32
     33
     34static inline int
     35arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
     36{
     37	int oldval = 0, ret;
     38
     39	if (!access_ok(uaddr, sizeof(u32)))
     40		return -EFAULT;
     41
     42	switch (op) {
     43	case FUTEX_OP_SET:
     44		__futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
     45		break;
     46	case FUTEX_OP_ADD:
     47		__futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
     48				  oparg);
     49		break;
     50	case FUTEX_OP_OR:
     51		__futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
     52				  oparg);
     53		break;
     54	case FUTEX_OP_ANDN:
     55		__futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
     56				  oldval, uaddr, oparg);
     57		break;
     58	case FUTEX_OP_XOR:
     59		__futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
     60				  oparg);
     61		break;
     62	default:
     63		ret = -ENOSYS;
     64	}
     65
     66	if (!ret)
     67		*oval = oldval;
     68
     69	return ret;
     70}
     71
     72static inline int
     73futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
     74			      u32 newval)
     75{
     76	int prev;
     77	int ret;
     78
     79	if (!access_ok(uaddr, sizeof(u32)))
     80		return -EFAULT;
     81
     82	__asm__ __volatile__ (
     83	"1: %1 = memw_locked(%3)\n"
     84	"   {\n"
     85	"      p2 = cmp.eq(%1,%4)\n"
     86	"      if (!p2.new) jump:NT 3f\n"
     87	"   }\n"
     88	"2: memw_locked(%3,p2) = %5\n"
     89	"   if (!p2) jump 1b\n"
     90	"3:\n"
     91	".section .fixup,\"ax\"\n"
     92	"4: %0 = #%6\n"
     93	"   jump ##3b\n"
     94	".previous\n"
     95	".section __ex_table,\"a\"\n"
     96	".long 1b,4b,2b,4b\n"
     97	".previous\n"
     98	: "+r" (ret), "=&r" (prev), "+m" (*uaddr)
     99	: "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
    100	: "p2", "memory");
    101
    102	*uval = prev;
    103	return ret;
    104}
    105
    106#endif /* __KERNEL__ */
    107#endif /* _ASM_HEXAGON_FUTEX_H */