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Diffstat (limited to 'arch/x86/include/asm/linkage.h')
-rw-r--r--arch/x86/include/asm/linkage.h65
1 files changed, 42 insertions, 23 deletions
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index 97a3de7892d3..9d38ae744a2e 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -8,6 +8,14 @@
#undef notrace
#define notrace __attribute__((no_instrument_function))
+#ifdef CONFIG_64BIT
+/*
+ * The generic version tends to create spurious ENDBR instructions under
+ * certain conditions.
+ */
+#define _THIS_IP_ ({ unsigned long __here; asm ("lea 0(%%rip), %0" : "=r" (__here)); __here; })
+#endif
+
#ifdef CONFIG_X86_32
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
#endif /* CONFIG_X86_32 */
@@ -30,31 +38,31 @@
#define ASM_FUNC_ALIGN __stringify(__FUNC_ALIGN)
#define SYM_F_ALIGN __FUNC_ALIGN
-#ifdef __ASSEMBLY__
+#ifdef __ASSEMBLER__
-#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
+#if defined(CONFIG_MITIGATION_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define RET jmp __x86_return_thunk
-#else /* CONFIG_RETPOLINE */
-#ifdef CONFIG_SLS
+#else /* CONFIG_MITIGATION_RETPOLINE */
+#ifdef CONFIG_MITIGATION_SLS
#define RET ret; int3
#else
#define RET ret
#endif
-#endif /* CONFIG_RETPOLINE */
+#endif /* CONFIG_MITIGATION_RETPOLINE */
-#else /* __ASSEMBLY__ */
+#else /* __ASSEMBLER__ */
-#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
+#if defined(CONFIG_MITIGATION_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define ASM_RET "jmp __x86_return_thunk\n\t"
-#else /* CONFIG_RETPOLINE */
-#ifdef CONFIG_SLS
+#else /* CONFIG_MITIGATION_RETPOLINE */
+#ifdef CONFIG_MITIGATION_SLS
#define ASM_RET "ret; int3\n\t"
#else
#define ASM_RET "ret\n\t"
#endif
-#endif /* CONFIG_RETPOLINE */
+#endif /* CONFIG_MITIGATION_RETPOLINE */
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
/*
* Depending on -fpatchable-function-entry=N,N usage (CONFIG_CALL_PADDING) the
@@ -97,6 +105,13 @@
CFI_POST_PADDING \
SYM_FUNC_END(__cfi_##name)
+/* UML needs to be able to override memcpy() and friends for KASAN. */
+#ifdef CONFIG_UML
+# define SYM_FUNC_ALIAS_MEMFUNC SYM_FUNC_ALIAS_WEAK
+#else
+# define SYM_FUNC_ALIAS_MEMFUNC SYM_FUNC_ALIAS
+#endif
+
/* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type */
#define SYM_TYPED_FUNC_START(name) \
SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \
@@ -104,33 +119,37 @@
/* SYM_FUNC_START -- use for global functions */
#define SYM_FUNC_START(name) \
- SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \
- ENDBR
+ SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN)
/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */
#define SYM_FUNC_START_NOALIGN(name) \
- SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) \
- ENDBR
+ SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
/* SYM_FUNC_START_LOCAL -- use for local functions */
#define SYM_FUNC_START_LOCAL(name) \
- SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN) \
- ENDBR
+ SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN)
/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */
#define SYM_FUNC_START_LOCAL_NOALIGN(name) \
- SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) \
- ENDBR
+ SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
/* SYM_FUNC_START_WEAK -- use for weak functions */
#define SYM_FUNC_START_WEAK(name) \
- SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN) \
- ENDBR
+ SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN)
/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */
#define SYM_FUNC_START_WEAK_NOALIGN(name) \
- SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \
- ENDBR
+ SYM_START(name, SYM_L_WEAK, SYM_A_NONE)
+
+/*
+ * Expose 'sym' to the startup code in arch/x86/boot/startup/, by emitting an
+ * alias prefixed with __pi_
+ */
+#ifdef __ASSEMBLER__
+#define SYM_PIC_ALIAS(sym) SYM_ALIAS(__pi_ ## sym, sym, SYM_L_GLOBAL)
+#else
+#define SYM_PIC_ALIAS(sym) extern typeof(sym) __PASTE(__pi_, sym) __alias(sym)
+#endif
#endif /* _ASM_X86_LINKAGE_H */