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-rw-r--r--Documentation/asm-annotations.rst16
-rw-r--r--include/linux/linkage.h37
-rw-r--r--tools/perf/util/include/linux/linkage.h35
3 files changed, 85 insertions, 3 deletions
diff --git a/Documentation/asm-annotations.rst b/Documentation/asm-annotations.rst
index f4bf0f6395fb..4868b58c60fb 100644
--- a/Documentation/asm-annotations.rst
+++ b/Documentation/asm-annotations.rst
@@ -130,8 +130,20 @@ denoting a range of code via ``SYM_*_START/END`` annotations.
In fact, this kind of annotation corresponds to the now deprecated ``ENTRY``
and ``ENDPROC`` macros.
-* ``SYM_FUNC_START_ALIAS`` and ``SYM_FUNC_START_LOCAL_ALIAS`` serve for those
- who decided to have two or more names for one function. The typical use is::
+* ``SYM_FUNC_ALIAS``, ``SYM_FUNC_ALIAS_LOCAL``, and ``SYM_FUNC_ALIAS_WEAK`` can
+ be used to define multiple names for a function. The typical use is::
+
+ SYM_FUNC_START(__memset)
+ ... asm insns ...
+ SYN_FUNC_END(__memset)
+ SYM_FUNC_ALIAS(memset, __memset)
+
+ In this example, one can call ``__memset`` or ``memset`` with the same
+ result, except the debug information for the instructions is generated to
+ the object file only once -- for the non-``ALIAS`` case.
+
+* ``SYM_FUNC_START_ALIAS`` and ``SYM_FUNC_START_LOCAL_ALIAS`` are deprecated
+ ways to define two or more names for one function. The typical use is::
SYM_FUNC_START_ALIAS(__memset)
SYM_FUNC_START(memset)
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index dbf8506decca..e574a84d8b11 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -165,7 +165,18 @@
#ifndef SYM_END
#define SYM_END(name, sym_type) \
.type name sym_type ASM_NL \
- .size name, .-name
+ .set .L__sym_size_##name, .-name ASM_NL \
+ .size name, .L__sym_size_##name
+#endif
+
+/* SYM_ALIAS -- use only if you have to */
+#ifndef SYM_ALIAS
+#define SYM_ALIAS(alias, name, sym_type, linkage) \
+ linkage(alias) ASM_NL \
+ .set alias, name ASM_NL \
+ .type alias sym_type ASM_NL \
+ .set .L__sym_size_##alias, .L__sym_size_##name ASM_NL \
+ .size alias, .L__sym_size_##alias
#endif
/* === code annotations === */
@@ -275,6 +286,30 @@
SYM_END(name, SYM_T_FUNC)
#endif
+/*
+ * SYM_FUNC_ALIAS -- define a global alias for an existing function
+ */
+#ifndef SYM_FUNC_ALIAS
+#define SYM_FUNC_ALIAS(alias, name) \
+ SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_GLOBAL)
+#endif
+
+/*
+ * SYM_FUNC_ALIAS_LOCAL -- define a local alias for an existing function
+ */
+#ifndef SYM_FUNC_ALIAS_LOCAL
+#define SYM_FUNC_ALIAS_LOCAL(alias, name) \
+ SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_LOCAL)
+#endif
+
+/*
+ * SYM_FUNC_ALIAS_WEAK -- define a weak global alias for an existing function
+ */
+#ifndef SYM_FUNC_ALIAS_WEAK
+#define SYM_FUNC_ALIAS_WEAK(alias, name) \
+ SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_WEAK)
+#endif
+
/* SYM_CODE_START -- use for non-C (special) functions */
#ifndef SYM_CODE_START
#define SYM_CODE_START(name) \
diff --git a/tools/perf/util/include/linux/linkage.h b/tools/perf/util/include/linux/linkage.h
index 5acf053fca7d..7b4cd7947e3f 100644
--- a/tools/perf/util/include/linux/linkage.h
+++ b/tools/perf/util/include/linux/linkage.h
@@ -50,9 +50,20 @@
#ifndef SYM_END
#define SYM_END(name, sym_type) \
.type name sym_type ASM_NL \
+ .set .L__sym_size_##name, .-name ASM_NL \
.size name, .-name
#endif
+/* SYM_ALIAS -- use only if you have to */
+#ifndef SYM_ALIAS
+#define SYM_ALIAS(alias, name, sym_type, linkage) \
+ linkage(alias) ASM_NL \
+ .set alias, name ASM_NL \
+ .type alias sym_type ASM_NL \
+ .set .L__sym_size_##alias, .L__sym_size_##name ASM_NL \
+ .size alias, .L__sym_size_##alias
+#endif
+
/*
* SYM_FUNC_START_ALIAS -- use where there are two global names for one
* function
@@ -101,4 +112,28 @@
SYM_END(name, SYM_T_FUNC)
#endif
+/*
+ * SYM_FUNC_ALIAS -- define a global alias for an existing function
+ */
+#ifndef SYM_FUNC_ALIAS
+#define SYM_FUNC_ALIAS(alias, name) \
+ SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_GLOBAL)
+#endif
+
+/*
+ * SYM_FUNC_ALIAS_LOCAL -- define a local alias for an existing function
+ */
+#ifndef SYM_FUNC_ALIAS_LOCAL
+#define SYM_FUNC_ALIAS_LOCAL(alias, name) \
+ SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_LOCAL)
+#endif
+
+/*
+ * SYM_FUNC_ALIAS_WEAK -- define a weak global alias for an existing function
+ */
+#ifndef SYM_FUNC_ALIAS_WEAK
+#define SYM_FUNC_ALIAS_WEAK(alias, name) \
+ SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_WEAK)
+#endif
+
#endif /* PERF_LINUX_LINKAGE_H_ */