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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/x86/include/asm/futex.h
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/futex.h')
-rw-r--r--arch/x86/include/asm/futex.h103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
new file mode 100644
index 0000000000..99d345b686
--- /dev/null
+++ b/arch/x86/include/asm/futex.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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/smap.h>
+
+#define unsafe_atomic_op1(insn, oval, uaddr, oparg, label) \
+do { \
+ int oldval = 0, ret; \
+ asm volatile("1:\t" insn "\n" \
+ "2:\n" \
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %1) \
+ : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
+ : "0" (oparg), "1" (0)); \
+ if (ret) \
+ goto label; \
+ *oval = oldval; \
+} while(0)
+
+
+#define unsafe_atomic_op2(insn, oval, uaddr, oparg, label) \
+do { \
+ int oldval = 0, ret, tem; \
+ asm volatile("1:\tmovl %2, %0\n" \
+ "2:\tmovl\t%0, %3\n" \
+ "\t" insn "\n" \
+ "3:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
+ "\tjnz\t2b\n" \
+ "4:\n" \
+ _ASM_EXTABLE_TYPE_REG(1b, 4b, EX_TYPE_EFAULT_REG, %1) \
+ _ASM_EXTABLE_TYPE_REG(3b, 4b, EX_TYPE_EFAULT_REG, %1) \
+ : "=&a" (oldval), "=&r" (ret), \
+ "+m" (*uaddr), "=&r" (tem) \
+ : "r" (oparg), "1" (0)); \
+ if (ret) \
+ goto label; \
+ *oval = oldval; \
+} while(0)
+
+static __always_inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
+ u32 __user *uaddr)
+{
+ if (!user_access_begin(uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ unsafe_atomic_op1("xchgl %0, %2", oval, uaddr, oparg, Efault);
+ break;
+ case FUTEX_OP_ADD:
+ unsafe_atomic_op1(LOCK_PREFIX "xaddl %0, %2", oval,
+ uaddr, oparg, Efault);
+ break;
+ case FUTEX_OP_OR:
+ unsafe_atomic_op2("orl %4, %3", oval, uaddr, oparg, Efault);
+ break;
+ case FUTEX_OP_ANDN:
+ unsafe_atomic_op2("andl %4, %3", oval, uaddr, ~oparg, Efault);
+ break;
+ case FUTEX_OP_XOR:
+ unsafe_atomic_op2("xorl %4, %3", oval, uaddr, oparg, Efault);
+ break;
+ default:
+ user_access_end();
+ return -ENOSYS;
+ }
+ user_access_end();
+ return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
+
+static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+
+ if (!user_access_begin(uaddr, sizeof(u32)))
+ return -EFAULT;
+ asm volatile("\n"
+ "1:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"
+ "2:\n"
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %0) \
+ : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
+ : "r" (newval), "1" (oldval)
+ : "memory"
+ );
+ user_access_end();
+ *uval = oldval;
+ return ret;
+}
+
+#endif
+#endif /* _ASM_X86_FUTEX_H */