futex.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_S390_FUTEX_H
  3#define _ASM_S390_FUTEX_H
  4
  5#include <linux/instrumented.h>
  6#include <linux/uaccess.h>
  7#include <linux/futex.h>
  8#include <asm/asm-extable.h>
  9#include <asm/mmu_context.h>
 10#include <asm/errno.h>
 11
 12#define FUTEX_OP_FUNC(name, insn)						\
 13static uaccess_kmsan_or_inline int						\
 14__futex_atomic_##name(int oparg, int *old, u32 __user *uaddr)			\
 15{										\
 16	bool sacf_flag;								\
 17	int rc, new;								\
 18										\
 19	instrument_copy_from_user_before(old, uaddr, sizeof(*old));		\
 20	sacf_flag = enable_sacf_uaccess();					\
 21	asm_inline volatile(							\
 22		"	sacf	256\n"						\
 23		"0:	l	%[old],%[uaddr]\n"				\
 24		"1:"insn							\
 25		"2:	cs	%[old],%[new],%[uaddr]\n"			\
 26		"3:	jl	1b\n"						\
 27		"	lhi	%[rc],0\n"					\
 28		"4:	sacf	768\n"						\
 29		EX_TABLE_UA_FAULT(0b, 4b, %[rc])				\
 30		EX_TABLE_UA_FAULT(1b, 4b, %[rc])				\
 31		EX_TABLE_UA_FAULT(2b, 4b, %[rc])				\
 32		EX_TABLE_UA_FAULT(3b, 4b, %[rc])				\
 33		: [rc] "=d" (rc), [old] "=&d" (*old),				\
 34		  [new] "=&d" (new), [uaddr] "+Q" (*uaddr)			\
 35		: [oparg] "d" (oparg)						\
 36		: "cc");							\
 37	disable_sacf_uaccess(sacf_flag);					\
 38	if (!rc)								\
 39		instrument_copy_from_user_after(old, uaddr, sizeof(*old), 0);	\
 40	return rc;								\
 41}
 42
 43FUTEX_OP_FUNC(set, "lr %[new],%[oparg]\n")
 44FUTEX_OP_FUNC(add, "lr %[new],%[old]\n ar %[new],%[oparg]\n")
 45FUTEX_OP_FUNC(or,  "lr %[new],%[old]\n or %[new],%[oparg]\n")
 46FUTEX_OP_FUNC(and, "lr %[new],%[old]\n nr %[new],%[oparg]\n")
 47FUTEX_OP_FUNC(xor, "lr %[new],%[old]\n xr %[new],%[oparg]\n")
 48
 49static inline
 50int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
 51{
 52	int old, rc;
 53
 54	switch (op) {
 55	case FUTEX_OP_SET:
 56		rc = __futex_atomic_set(oparg, &old, uaddr);
 57		break;
 58	case FUTEX_OP_ADD:
 59		rc = __futex_atomic_add(oparg, &old, uaddr);
 60		break;
 61	case FUTEX_OP_OR:
 62		rc = __futex_atomic_or(oparg, &old, uaddr);
 63		break;
 64	case FUTEX_OP_ANDN:
 65		rc = __futex_atomic_and(~oparg, &old, uaddr);
 66		break;
 67	case FUTEX_OP_XOR:
 68		rc = __futex_atomic_xor(oparg, &old, uaddr);
 69		break;
 70	default:
 71		rc = -ENOSYS;
 72	}
 73	if (!rc)
 74		*oval = old;
 75	return rc;
 76}
 77
 78static uaccess_kmsan_or_inline
 79int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval)
 80{
 81	bool sacf_flag;
 82	int rc;
 83
 84	instrument_copy_from_user_before(uval, uaddr, sizeof(*uval));
 85	sacf_flag = enable_sacf_uaccess();
 86	asm_inline volatile(
 87		"	sacf	256\n"
 88		"0:	cs	%[old],%[new],%[uaddr]\n"
 89		"1:	lhi	%[rc],0\n"
 90		"2:	sacf	768\n"
 91		EX_TABLE_UA_FAULT(0b, 2b, %[rc])
 92		EX_TABLE_UA_FAULT(1b, 2b, %[rc])
 93		: [rc] "=d" (rc), [old] "+d" (oldval), [uaddr] "+Q" (*uaddr)
 94		: [new] "d" (newval)
 95		: "cc", "memory");
 96	disable_sacf_uaccess(sacf_flag);
 97	*uval = oldval;
 98	instrument_copy_from_user_after(uval, uaddr, sizeof(*uval), 0);
 99	return rc;
100}
101
102#endif /* _ASM_S390_FUTEX_H */