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Diffstat (limited to 'arch/x86/include/asm/special_insns.h')
-rw-r--r--arch/x86/include/asm/special_insns.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index de48d1389936..d6cd9344f6c7 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -202,6 +202,19 @@ static inline void clwb(volatile void *__p)
: [pax] "a" (p));
}
+#ifdef CONFIG_X86_USER_SHADOW_STACK
+static inline int write_user_shstk_64(u64 __user *addr, u64 val)
+{
+ asm_volatile_goto("1: wrussq %[val], (%[addr])\n"
+ _ASM_EXTABLE(1b, %l[fail])
+ :: [addr] "r" (addr), [val] "r" (val)
+ :: fail);
+ return 0;
+fail:
+ return -EFAULT;
+}
+#endif /* CONFIG_X86_USER_SHADOW_STACK */
+
#define nop() asm volatile ("nop")
static inline void serialize(void)