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* [PATCH v3 0/5] linkage: better symbol aliasing
@ 2022-02-11 15:14 Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 1/5] linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}() Mark Rutland
                   ` (5 more replies)
  0 siblings, 6 replies; 9+ messages in thread
From: Mark Rutland @ 2022-02-11 15:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: acme, ardb, bp, broonie, catalin.marinas, dave.hansen, jpoimboe,
	jslaby, linux-arm-kernel, mark.rutland, mingo, ndesaulniers,
	peterz, tglx, will

This series aims to make symbol aliasing simpler and more consistent.
The basic idea is to replace SYM_FUNC_START_ALIAS(alias) and
SYM_FUNC_END_ALIAS(alias) with a new SYM_FUNC_ALIAS(alias, name), so
that e.g.

    SYM_FUNC_START(func)
    SYM_FUNC_START_ALIAS(alias1)
    SYM_FUNC_START_ALIAS(alias2)
        ... asm insns ...
    SYM_FUNC_END(func)
    SYM_FUNC_END_ALIAS(alias1)
    SYM_FUNC_END_ALIAS(alias2)
    EXPORT_SYMBOL(alias1)
    EXPORT_SYMBOL(alias2)

... can become:

    SYM_FUNC_START(name)
        ... asm insns ...
    SYM_FUNC_END(name)

    SYM_FUNC_ALIAS(alias1, func)
    EXPORT_SYMBOL(alias1)

    SYM_FUNC_ALIAS(alias2, func)
    EXPORT_SYMBOL(alias2)

This avoids repetition and hopefully make it easier to ensure
consistency (e.g. so each function has a single canonical name and
associated metadata).

I've build-tested the following with both GCC 10.3.0 and LLVM 13.0.0
without issues (ignoring any existing warnings):

* arm omap1_defconfig (v2 broke with LLVM here)
* arm multi_v7_defconfig
* arm64 defconfig
* i386 defconfig
* x86_64 defconfig

I've boot-tested the arm64 Images.

I've pushed the series to my `linkage/alias-rework` branch on git.kernel.org,
atop v5.17-rc2:

  git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git linkage/alias-rework
  https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=linkage/alias-rework

Since RFCv1 [1]:
* Drop arm64 dma alias removal (taken via arm64 for v5.17-rc1)
* Rename SYM_FUNC_LOCAL_ALIAS() -> SYM_FUNC_ALIAS_LOCAL()
* Update the tools/ copies of x86 routines
* Add preparatory fix for 32-bit arm
* Rebase to v5.17-rc1

Since v2 [2]:
* Rework to be LLVM-compatible
  - Drop SYM_ENTRY_AT() / SYM_END_AT()
  - Drop unnecessary local symbols
  - Calculate size in SYM_END()
  - Use common SYM_ALIAS()
* Drop newly redundant arch/arm changes
* Clarify commit message wording
* Fix typos

[1] https://lore.kernel.org/r/20211206124715.4101571-1-mark.rutland@arm.com/
[2] https://lore.kernel.org/r/20220125113200.3829108-1-mark.rutland@arm.com/

Thanks,
Mark.

Mark Rutland (5):
  linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}()
  arm64: clean up symbol aliasing
  x86: clean up symbol aliasing
  linkage: remove SYM_FUNC_{START,END}_ALIAS()
  tools: update x86 string routines

 Documentation/asm-annotations.rst       | 11 ++--
 arch/arm64/include/asm/linkage.h        | 24 ---------
 arch/arm64/kvm/hyp/nvhe/cache.S         |  5 +-
 arch/arm64/lib/clear_page.S             |  5 +-
 arch/arm64/lib/copy_page.S              |  5 +-
 arch/arm64/lib/memchr.S                 |  5 +-
 arch/arm64/lib/memcmp.S                 |  6 +--
 arch/arm64/lib/memcpy.S                 | 21 ++++----
 arch/arm64/lib/memset.S                 | 12 +++--
 arch/arm64/lib/strchr.S                 |  6 ++-
 arch/arm64/lib/strcmp.S                 |  6 +--
 arch/arm64/lib/strlen.S                 |  6 +--
 arch/arm64/lib/strncmp.S                |  6 +--
 arch/arm64/lib/strnlen.S                |  6 ++-
 arch/arm64/lib/strrchr.S                |  5 +-
 arch/arm64/mm/cache.S                   | 35 +++++++------
 arch/x86/boot/compressed/head_32.S      |  3 +-
 arch/x86/boot/compressed/head_64.S      |  3 +-
 arch/x86/crypto/aesni-intel_asm.S       |  4 +-
 arch/x86/lib/memcpy_64.S                | 10 ++--
 arch/x86/lib/memmove_64.S               |  4 +-
 arch/x86/lib/memset_64.S                |  6 +--
 include/linux/linkage.h                 | 67 +++++++++++++------------
 tools/arch/x86/lib/memcpy_64.S          | 10 ++--
 tools/arch/x86/lib/memset_64.S          |  6 +--
 tools/perf/util/include/linux/linkage.h | 46 ++++++++++++-----
 26 files changed, 169 insertions(+), 154 deletions(-)

-- 
2.30.2


^ permalink raw reply	[flat|nested] 9+ messages in thread
* [PATCH v3 1/5] linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}()
  2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
@ 2022-02-11 15:14 ` Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 2/5] arm64: clean up symbol aliasing Mark Rutland
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 9+ messages in thread
From: Mark Rutland @ 2022-02-11 15:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: acme, ardb, bp, broonie, catalin.marinas, dave.hansen, jpoimboe,
	jslaby, linux-arm-kernel, mark.rutland, mingo, ndesaulniers,
	peterz, tglx, will

Currently aliasing an asm function requires adding START and END
annotations for each name, as per Documentation/asm-annotations.rst:

	SYM_FUNC_START_ALIAS(__memset)
	SYM_FUNC_START(memset)
	    ... asm insns ...
	SYM_FUNC_END(memset)
	SYM_FUNC_END_ALIAS(__memset)

This is more painful than necessary to maintain, especially where a
function has many aliases, some of which we may wish to define
conditionally. For example, arm64's memcpy/memmove implementation (which
uses some arch-specific SYM_*() helpers) has:

	SYM_FUNC_START_ALIAS(__memmove)
	SYM_FUNC_START_ALIAS_WEAK_PI(memmove)
	SYM_FUNC_START_ALIAS(__memcpy)
	SYM_FUNC_START_WEAK_PI(memcpy)
	    ... asm insns ...
	SYM_FUNC_END_PI(memcpy)
	EXPORT_SYMBOL(memcpy)
	SYM_FUNC_END_ALIAS(__memcpy)
	EXPORT_SYMBOL(__memcpy)
	SYM_FUNC_END_ALIAS_PI(memmove)
	EXPORT_SYMBOL(memmove)
	SYM_FUNC_END_ALIAS(__memmove)
	EXPORT_SYMBOL(__memmove)
	SYM_FUNC_START(name)

It would be much nicer if we could define the aliases *after* the
standard function definition. This would avoid the need to specify each
symbol name twice, and would make it easier to spot the canonical
function definition.

This patch adds new macros to allow us to do so, which allows the above
example to be rewritten more succinctly as:

	SYM_FUNC_START(__pi_memcpy)
	    ... asm insns ...
	SYM_FUNC_END(__pi_memcpy)

	SYM_FUNC_ALIAS(__memcpy, __pi_memcpy)
	EXPORT_SYMBOL(__memcpy)
	SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
	EXPORT_SYMBOL(memcpy)

	SYM_FUNC_ALIAS(__pi_memmove, __pi_memcpy)
	SYM_FUNC_ALIAS(__memmove, __pi_memmove)
	EXPORT_SYMBOL(__memmove)
	SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
	EXPORT_SYMBOL(memmove)

The reduction in duplication will also make it possible to replace some
uses of WEAK with more accurate Kconfig guards, e.g.

	#ifndef CONFIG_KASAN
	SYM_FUNC_ALIAS(memmove, __memmove)
	EXPORT_SYMBOL(memmove)
	#endif

... which should make it easier to ensure that symbols are neither used
nor overidden unexpectedly.

The existing SYM_FUNC_START_ALIAS() and SYM_FUNC_START_LOCAL_ALIAS() are
marked as deprecated, and will be removed once existing users are moved
over to the new scheme.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
 Documentation/asm-annotations.rst | 16 +++++++++++--
 include/linux/linkage.h           | 37 ++++++++++++++++++++++++++++++-
 2 files changed, 50 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..aca8f5cb9c3c 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_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 -- 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_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)				\
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 9+ messages in thread
* [PATCH v3 2/5] arm64: clean up symbol aliasing
  2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 1/5] linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}() Mark Rutland
@ 2022-02-11 15:14 ` Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 3/5] x86: " Mark Rutland
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 9+ messages in thread
From: Mark Rutland @ 2022-02-11 15:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: acme, ardb, bp, broonie, catalin.marinas, dave.hansen, jpoimboe,
	jslaby, linux-arm-kernel, mark.rutland, mingo, ndesaulniers,
	peterz, tglx, will

Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those
to simplify and more consistently define function aliases across
arch/arm64.

Aliases are now defined in terms of a canonical function name. For
position-independent functions I've made the __pi_<func> name the
canonical name, and defined other alises in terms of this.

The SYM_FUNC_{START,END}_PI(func) macros obscure the __pi_<func> name,
and make this hard to seatch for. The SYM_FUNC_START_WEAK_PI() macro
also obscures the fact that the __pi_<func> fymbol is global and the
<func> symbol is weak. For clarity, I have removed these macros and used
SYM_FUNC_{START,END}() directly with the __pi_<func> name.

For example:

    SYM_FUNC_START_WEAK_PI(func)
        ... asm insns ...
    SYM_FUNC_END_PI(func)
    EXPORT_SYMBOL(func)

... becomes:

    SYM_FUNC_START(__pi_func)
        ... asm insns ...
    SYM_FUNC_END(__pi_func)

    SYM_FUNC_ALIAS_WEAK(func, __pi_func)
    EXPORT_SYMBOL(func)

For clarity, where there are multiple annotations such as
EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For
example, where a function has a name and an alias which are both
exported, this is organised as:

    SYM_FUNC_START(func)
	... asm insns ...
    SYM_FUNC_END(func)
    EXPORT_SYMBOL(func)

    SYM_FUNC_ALAIAS(alias, func)
    EXPORT_SYMBOL(alias)

For consistency with the other string functions, I've defined strrchr as
a position-independent function, as it can safely be used as such even
though we have no users today.

As we no longer use SYM_FUNC_{START,END}_ALIAS(), our local copies are
removed. The common versions will be removed by a subsequent patch.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/include/asm/linkage.h | 24 ----------------------
 arch/arm64/kvm/hyp/nvhe/cache.S  |  5 +++--
 arch/arm64/lib/clear_page.S      |  5 +++--
 arch/arm64/lib/copy_page.S       |  5 +++--
 arch/arm64/lib/memchr.S          |  5 +++--
 arch/arm64/lib/memcmp.S          |  6 +++---
 arch/arm64/lib/memcpy.S          | 21 ++++++++++---------
 arch/arm64/lib/memset.S          | 12 ++++++-----
 arch/arm64/lib/strchr.S          |  6 ++++--
 arch/arm64/lib/strcmp.S          |  6 +++---
 arch/arm64/lib/strlen.S          |  6 +++---
 arch/arm64/lib/strncmp.S         |  6 +++---
 arch/arm64/lib/strnlen.S         |  6 ++++--
 arch/arm64/lib/strrchr.S         |  5 +++--
 arch/arm64/mm/cache.S            | 35 +++++++++++++++++++-------------
 15 files changed, 74 insertions(+), 79 deletions(-)

diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h
index b77e9b3f5371..43f8c25b3fda 100644
--- a/arch/arm64/include/asm/linkage.h
+++ b/arch/arm64/include/asm/linkage.h
@@ -39,28 +39,4 @@
 	SYM_START(name, SYM_L_WEAK, SYM_A_NONE)		\
 	bti c ;
 
-/*
- * Annotate a function as position independent, i.e., safe to be called before
- * the kernel virtual mapping is activated.
- */
-#define SYM_FUNC_START_PI(x)			\
-		SYM_FUNC_START_ALIAS(__pi_##x);	\
-		SYM_FUNC_START(x)
-
-#define SYM_FUNC_START_WEAK_PI(x)		\
-		SYM_FUNC_START_ALIAS(__pi_##x);	\
-		SYM_FUNC_START_WEAK(x)
-
-#define SYM_FUNC_START_WEAK_ALIAS_PI(x)		\
-		SYM_FUNC_START_ALIAS(__pi_##x);	\
-		SYM_START(x, SYM_L_WEAK, SYM_A_ALIGN)
-
-#define SYM_FUNC_END_PI(x)			\
-		SYM_FUNC_END(x);		\
-		SYM_FUNC_END_ALIAS(__pi_##x)
-
-#define SYM_FUNC_END_ALIAS_PI(x)		\
-		SYM_FUNC_END_ALIAS(x);		\
-		SYM_FUNC_END_ALIAS(__pi_##x)
-
 #endif
diff --git a/arch/arm64/kvm/hyp/nvhe/cache.S b/arch/arm64/kvm/hyp/nvhe/cache.S
index 958734f4d6b0..0c367eb5f4e2 100644
--- a/arch/arm64/kvm/hyp/nvhe/cache.S
+++ b/arch/arm64/kvm/hyp/nvhe/cache.S
@@ -7,7 +7,8 @@
 #include <asm/assembler.h>
 #include <asm/alternative.h>
 
-SYM_FUNC_START_PI(dcache_clean_inval_poc)
+SYM_FUNC_START(__pi_dcache_clean_inval_poc)
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
-SYM_FUNC_END_PI(dcache_clean_inval_poc)
+SYM_FUNC_END(__pi_dcache_clean_inval_poc)
+SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc)
diff --git a/arch/arm64/lib/clear_page.S b/arch/arm64/lib/clear_page.S
index 1fd5d790ab80..ebde40e7fa2b 100644
--- a/arch/arm64/lib/clear_page.S
+++ b/arch/arm64/lib/clear_page.S
@@ -14,7 +14,7 @@
  * Parameters:
  *	x0 - dest
  */
-SYM_FUNC_START_PI(clear_page)
+SYM_FUNC_START(__pi_clear_page)
 	mrs	x1, dczid_el0
 	tbnz	x1, #4, 2f	/* Branch if DC ZVA is prohibited */
 	and	w1, w1, #0xf
@@ -35,5 +35,6 @@ SYM_FUNC_START_PI(clear_page)
 	tst	x0, #(PAGE_SIZE - 1)
 	b.ne	2b
 	ret
-SYM_FUNC_END_PI(clear_page)
+SYM_FUNC_END(__pi_clear_page)
+SYM_FUNC_ALIAS(clear_page, __pi_clear_page)
 EXPORT_SYMBOL(clear_page)
diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S
index 29144f4cd449..c336d2ffdec5 100644
--- a/arch/arm64/lib/copy_page.S
+++ b/arch/arm64/lib/copy_page.S
@@ -17,7 +17,7 @@
  *	x0 - dest
  *	x1 - src
  */
-SYM_FUNC_START_PI(copy_page)
+SYM_FUNC_START(__pi_copy_page)
 alternative_if ARM64_HAS_NO_HW_PREFETCH
 	// Prefetch three cache lines ahead.
 	prfm	pldl1strm, [x1, #128]
@@ -75,5 +75,6 @@ alternative_else_nop_endif
 	stnp	x16, x17, [x0, #112 - 256]
 
 	ret
-SYM_FUNC_END_PI(copy_page)
+SYM_FUNC_END(__pi_copy_page)
+SYM_FUNC_ALIAS(copy_page, __pi_copy_page)
 EXPORT_SYMBOL(copy_page)
diff --git a/arch/arm64/lib/memchr.S b/arch/arm64/lib/memchr.S
index 7c2276fdab54..37a9f2a4f7f4 100644
--- a/arch/arm64/lib/memchr.S
+++ b/arch/arm64/lib/memchr.S
@@ -38,7 +38,7 @@
 
 	.p2align 4
 	nop
-SYM_FUNC_START_WEAK_PI(memchr)
+SYM_FUNC_START(__pi_memchr)
 	and	chrin, chrin, #0xff
 	lsr	wordcnt, cntin, #3
 	cbz	wordcnt, L(byte_loop)
@@ -71,5 +71,6 @@ CPU_LE(	rev	tmp, tmp)
 L(not_found):
 	mov	result, #0
 	ret
-SYM_FUNC_END_PI(memchr)
+SYM_FUNC_END(__pi_memchr)
+SYM_FUNC_ALIAS_WEAK(memchr, __pi_memchr)
 EXPORT_SYMBOL_NOKASAN(memchr)
diff --git a/arch/arm64/lib/memcmp.S b/arch/arm64/lib/memcmp.S
index 7d956384222f..a5ccf2c55f91 100644
--- a/arch/arm64/lib/memcmp.S
+++ b/arch/arm64/lib/memcmp.S
@@ -32,7 +32,7 @@
 #define tmp1		x7
 #define tmp2		x8
 
-SYM_FUNC_START_WEAK_PI(memcmp)
+SYM_FUNC_START(__pi_memcmp)
 	subs	limit, limit, 8
 	b.lo	L(less8)
 
@@ -134,6 +134,6 @@ L(byte_loop):
 	b.eq	L(byte_loop)
 	sub	result, data1w, data2w
 	ret
-
-SYM_FUNC_END_PI(memcmp)
+SYM_FUNC_END(__pi_memcmp)
+SYM_FUNC_ALIAS_WEAK(memcmp, __pi_memcmp)
 EXPORT_SYMBOL_NOKASAN(memcmp)
diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index b82fd64ee1e1..4ab48d49c451 100644
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -57,10 +57,7 @@
    The loop tail is handled by always copying 64 bytes from the end.
 */
 
-SYM_FUNC_START_ALIAS(__memmove)
-SYM_FUNC_START_WEAK_ALIAS_PI(memmove)
-SYM_FUNC_START_ALIAS(__memcpy)
-SYM_FUNC_START_WEAK_PI(memcpy)
+SYM_FUNC_START(__pi_memcpy)
 	add	srcend, src, count
 	add	dstend, dstin, count
 	cmp	count, 128
@@ -241,12 +238,16 @@ L(copy64_from_start):
 	stp	B_l, B_h, [dstin, 16]
 	stp	C_l, C_h, [dstin]
 	ret
+SYM_FUNC_END(__pi_memcpy)
 
-SYM_FUNC_END_PI(memcpy)
-EXPORT_SYMBOL(memcpy)
-SYM_FUNC_END_ALIAS(__memcpy)
+SYM_FUNC_ALIAS(__memcpy, __pi_memcpy)
 EXPORT_SYMBOL(__memcpy)
-SYM_FUNC_END_ALIAS_PI(memmove)
-EXPORT_SYMBOL(memmove)
-SYM_FUNC_END_ALIAS(__memmove)
+SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+EXPORT_SYMBOL(memcpy)
+
+SYM_FUNC_ALIAS(__pi_memmove, __pi_memcpy)
+
+SYM_FUNC_ALIAS(__memmove, __pi_memmove)
 EXPORT_SYMBOL(__memmove)
+SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
+EXPORT_SYMBOL(memmove)
diff --git a/arch/arm64/lib/memset.S b/arch/arm64/lib/memset.S
index a9c1c9a01ea9..a5aebe82ad73 100644
--- a/arch/arm64/lib/memset.S
+++ b/arch/arm64/lib/memset.S
@@ -42,8 +42,7 @@ dst		.req	x8
 tmp3w		.req	w9
 tmp3		.req	x9
 
-SYM_FUNC_START_ALIAS(__memset)
-SYM_FUNC_START_WEAK_PI(memset)
+SYM_FUNC_START(__pi_memset)
 	mov	dst, dstin	/* Preserve return value.  */
 	and	A_lw, val, #255
 	orr	A_lw, A_lw, A_lw, lsl #8
@@ -202,7 +201,10 @@ SYM_FUNC_START_WEAK_PI(memset)
 	ands	count, count, zva_bits_x
 	b.ne	.Ltail_maybe_long
 	ret
-SYM_FUNC_END_PI(memset)
-EXPORT_SYMBOL(memset)
-SYM_FUNC_END_ALIAS(__memset)
+SYM_FUNC_END(__pi_memset)
+
+SYM_FUNC_ALIAS(__memset, __pi_memset)
 EXPORT_SYMBOL(__memset)
+
+SYM_FUNC_ALIAS_WEAK(memset, __pi_memset)
+EXPORT_SYMBOL(memset)
diff --git a/arch/arm64/lib/strchr.S b/arch/arm64/lib/strchr.S
index 1f47eae3b0d6..94ee67a6b212 100644
--- a/arch/arm64/lib/strchr.S
+++ b/arch/arm64/lib/strchr.S
@@ -18,7 +18,7 @@
  * Returns:
  *	x0 - address of first occurrence of 'c' or 0
  */
-SYM_FUNC_START_WEAK(strchr)
+SYM_FUNC_START(__pi_strchr)
 	and	w1, w1, #0xff
 1:	ldrb	w2, [x0], #1
 	cmp	w2, w1
@@ -28,5 +28,7 @@ SYM_FUNC_START_WEAK(strchr)
 	cmp	w2, w1
 	csel	x0, x0, xzr, eq
 	ret
-SYM_FUNC_END(strchr)
+SYM_FUNC_END(__pi_strchr)
+
+SYM_FUNC_ALIAS_WEAK(strchr, __pi_strchr)
 EXPORT_SYMBOL_NOKASAN(strchr)
diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S
index 83bcad72ec97..cda7de747efc 100644
--- a/arch/arm64/lib/strcmp.S
+++ b/arch/arm64/lib/strcmp.S
@@ -41,7 +41,7 @@
 
 	/* Start of performance-critical section  -- one 64B cache line.  */
 	.align 6
-SYM_FUNC_START_WEAK_PI(strcmp)
+SYM_FUNC_START(__pi_strcmp)
 	eor	tmp1, src1, src2
 	mov	zeroones, #REP8_01
 	tst	tmp1, #7
@@ -171,6 +171,6 @@ L(loop_misaligned):
 L(done):
 	sub	result, data1, data2
 	ret
-
-SYM_FUNC_END_PI(strcmp)
+SYM_FUNC_END(__pi_strcmp)
+SYM_FUNC_ALIAS_WEAK(strcmp, __pi_strcmp)
 EXPORT_SYMBOL_NOHWKASAN(strcmp)
diff --git a/arch/arm64/lib/strlen.S b/arch/arm64/lib/strlen.S
index 1648790e91b3..4919fe81ae54 100644
--- a/arch/arm64/lib/strlen.S
+++ b/arch/arm64/lib/strlen.S
@@ -79,7 +79,7 @@
 	   whether the first fetch, which may be misaligned, crosses a page
 	   boundary.  */
 
-SYM_FUNC_START_WEAK_PI(strlen)
+SYM_FUNC_START(__pi_strlen)
 	and	tmp1, srcin, MIN_PAGE_SIZE - 1
 	mov	zeroones, REP8_01
 	cmp	tmp1, MIN_PAGE_SIZE - 16
@@ -208,6 +208,6 @@ L(page_cross):
 	csel	data1, data1, tmp4, eq
 	csel	data2, data2, tmp2, eq
 	b	L(page_cross_entry)
-
-SYM_FUNC_END_PI(strlen)
+SYM_FUNC_END(__pi_strlen)
+SYM_FUNC_ALIAS_WEAK(strlen, __pi_strlen)
 EXPORT_SYMBOL_NOKASAN(strlen)
diff --git a/arch/arm64/lib/strncmp.S b/arch/arm64/lib/strncmp.S
index e42bcfcd37e6..a848abcec975 100644
--- a/arch/arm64/lib/strncmp.S
+++ b/arch/arm64/lib/strncmp.S
@@ -44,7 +44,7 @@
 #define endloop		x15
 #define count		mask
 
-SYM_FUNC_START_WEAK_PI(strncmp)
+SYM_FUNC_START(__pi_strncmp)
 	cbz	limit, L(ret0)
 	eor	tmp1, src1, src2
 	mov	zeroones, #REP8_01
@@ -256,6 +256,6 @@ L(done_loop):
 L(ret0):
 	mov	result, #0
 	ret
-
-SYM_FUNC_END_PI(strncmp)
+SYM_FUNC_END(__pi_strncmp)
+SYM_FUNC_ALIAS_WEAK(strncmp, __pi_strncmp)
 EXPORT_SYMBOL_NOHWKASAN(strncmp)
diff --git a/arch/arm64/lib/strnlen.S b/arch/arm64/lib/strnlen.S
index b72913a99038..d5ac0e10a01d 100644
--- a/arch/arm64/lib/strnlen.S
+++ b/arch/arm64/lib/strnlen.S
@@ -47,7 +47,7 @@ limit_wd	.req	x14
 #define REP8_7f 0x7f7f7f7f7f7f7f7f
 #define REP8_80 0x8080808080808080
 
-SYM_FUNC_START_WEAK_PI(strnlen)
+SYM_FUNC_START(__pi_strnlen)
 	cbz	limit, .Lhit_limit
 	mov	zeroones, #REP8_01
 	bic	src, srcin, #15
@@ -156,5 +156,7 @@ CPU_LE( lsr	tmp2, tmp2, tmp4 )	/* Shift (tmp1 & 63).  */
 .Lhit_limit:
 	mov	len, limit
 	ret
-SYM_FUNC_END_PI(strnlen)
+SYM_FUNC_END(__pi_strnlen)
+
+SYM_FUNC_ALIAS_WEAK(strnlen, __pi_strnlen)
 EXPORT_SYMBOL_NOKASAN(strnlen)
diff --git a/arch/arm64/lib/strrchr.S b/arch/arm64/lib/strrchr.S
index 13132d1ed6d1..a5123cf0ce12 100644
--- a/arch/arm64/lib/strrchr.S
+++ b/arch/arm64/lib/strrchr.S
@@ -18,7 +18,7 @@
  * Returns:
  *	x0 - address of last occurrence of 'c' or 0
  */
-SYM_FUNC_START_WEAK_PI(strrchr)
+SYM_FUNC_START(__pi_strrchr)
 	mov	x3, #0
 	and	w1, w1, #0xff
 1:	ldrb	w2, [x0], #1
@@ -29,5 +29,6 @@ SYM_FUNC_START_WEAK_PI(strrchr)
 	b	1b
 2:	mov	x0, x3
 	ret
-SYM_FUNC_END_PI(strrchr)
+SYM_FUNC_END(__pi_strrchr)
+SYM_FUNC_ALIAS_WEAK(strrchr, __pi_strrchr)
 EXPORT_SYMBOL_NOKASAN(strrchr)
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index 7d0563db4201..0ea6cc25dc66 100644
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -107,10 +107,11 @@ SYM_FUNC_END(icache_inval_pou)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
-SYM_FUNC_START_PI(dcache_clean_inval_poc)
+SYM_FUNC_START(__pi_dcache_clean_inval_poc)
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
-SYM_FUNC_END_PI(dcache_clean_inval_poc)
+SYM_FUNC_END(__pi_dcache_clean_inval_poc)
+SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc)
 
 /*
  *	dcache_clean_pou(start, end)
@@ -140,7 +141,7 @@ SYM_FUNC_END(dcache_clean_pou)
  *	- start   - kernel start address of region
  *	- end     - kernel end address of region
  */
-SYM_FUNC_START_PI(dcache_inval_poc)
+SYM_FUNC_START(__pi_dcache_inval_poc)
 	dcache_line_size x2, x3
 	sub	x3, x2, #1
 	tst	x1, x3				// end cache line aligned?
@@ -158,7 +159,8 @@ SYM_FUNC_START_PI(dcache_inval_poc)
 	b.lo	2b
 	dsb	sy
 	ret
-SYM_FUNC_END_PI(dcache_inval_poc)
+SYM_FUNC_END(__pi_dcache_inval_poc)
+SYM_FUNC_ALIAS(dcache_inval_poc, __pi_dcache_inval_poc)
 
 /*
  *	dcache_clean_poc(start, end)
@@ -169,10 +171,11 @@ SYM_FUNC_END_PI(dcache_inval_poc)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
-SYM_FUNC_START_PI(dcache_clean_poc)
+SYM_FUNC_START(__pi_dcache_clean_poc)
 	dcache_by_line_op cvac, sy, x0, x1, x2, x3
 	ret
-SYM_FUNC_END_PI(dcache_clean_poc)
+SYM_FUNC_END(__pi_dcache_clean_poc)
+SYM_FUNC_ALIAS(dcache_clean_poc, __pi_dcache_clean_poc)
 
 /*
  *	dcache_clean_pop(start, end)
@@ -183,13 +186,14 @@ SYM_FUNC_END_PI(dcache_clean_poc)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
-SYM_FUNC_START_PI(dcache_clean_pop)
+SYM_FUNC_START(__pi_dcache_clean_pop)
 	alternative_if_not ARM64_HAS_DCPOP
 	b	dcache_clean_poc
 	alternative_else_nop_endif
 	dcache_by_line_op cvap, sy, x0, x1, x2, x3
 	ret
-SYM_FUNC_END_PI(dcache_clean_pop)
+SYM_FUNC_END(__pi_dcache_clean_pop)
+SYM_FUNC_ALIAS(dcache_clean_pop, __pi_dcache_clean_pop)
 
 /*
  *	__dma_flush_area(start, size)
@@ -199,11 +203,12 @@ SYM_FUNC_END_PI(dcache_clean_pop)
  *	- start   - virtual start address of region
  *	- size    - size in question
  */
-SYM_FUNC_START_PI(__dma_flush_area)
+SYM_FUNC_START(__pi___dma_flush_area)
 	add	x1, x0, x1
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
-SYM_FUNC_END_PI(__dma_flush_area)
+SYM_FUNC_END(__pi___dma_flush_area)
+SYM_FUNC_ALIAS(__dma_flush_area, __pi___dma_flush_area)
 
 /*
  *	__dma_map_area(start, size, dir)
@@ -211,12 +216,13 @@ SYM_FUNC_END_PI(__dma_flush_area)
  *	- size	- size of region
  *	- dir	- DMA direction
  */
-SYM_FUNC_START_PI(__dma_map_area)
+SYM_FUNC_START(__pi___dma_map_area)
 	add	x1, x0, x1
 	cmp	w2, #DMA_FROM_DEVICE
 	b.eq	__pi_dcache_inval_poc
 	b	__pi_dcache_clean_poc
-SYM_FUNC_END_PI(__dma_map_area)
+SYM_FUNC_END(__pi___dma_map_area)
+SYM_FUNC_ALIAS(__dma_map_area, __pi___dma_map_area)
 
 /*
  *	__dma_unmap_area(start, size, dir)
@@ -224,9 +230,10 @@ SYM_FUNC_END_PI(__dma_map_area)
  *	- size	- size of region
  *	- dir	- DMA direction
  */
-SYM_FUNC_START_PI(__dma_unmap_area)
+SYM_FUNC_START(__pi___dma_unmap_area)
 	add	x1, x0, x1
 	cmp	w2, #DMA_TO_DEVICE
 	b.ne	__pi_dcache_inval_poc
 	ret
-SYM_FUNC_END_PI(__dma_unmap_area)
+SYM_FUNC_END(__pi___dma_unmap_area)
+SYM_FUNC_ALIAS(__dma_unmap_area, __pi___dma_unmap_area)
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 9+ messages in thread
* [PATCH v3 3/5] x86: clean up symbol aliasing
  2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 1/5] linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}() Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 2/5] arm64: clean up symbol aliasing Mark Rutland
@ 2022-02-11 15:14 ` Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 4/5] linkage: remove SYM_FUNC_{START,END}_ALIAS() Mark Rutland
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 9+ messages in thread
From: Mark Rutland @ 2022-02-11 15:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: acme, ardb, bp, broonie, catalin.marinas, dave.hansen, jpoimboe,
	jslaby, linux-arm-kernel, mark.rutland, mingo, ndesaulniers,
	peterz, tglx, will

Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those
to simplify the definition of function aliases across arch/x86.

For clarity, where there are multiple annotations such as
EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For
example, where a function has a name and an alias which are both
exported, this is organised as:

	SYM_FUNC_START(func)
	    ... asm insns ...
	SYM_FUNC_END(func)
	EXPORT_SYMBOL(func)

	SYM_FUNC_ALIAS(alias, func)
	EXPORT_SYMBOL(alias)

Where there are only aliases and no exports or other annotations, I have
not bothered with line spacing, e.g.

	SYM_FUNC_START(func)
	    ... asm insns ...
	SYM_FUNC_END(func)
	SYM_FUNC_ALAIAS(alias, func)

There should be no functional change as a result of this patch.

The x86 string routines under tools/ will be handled by a subsequent
patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/boot/compressed/head_32.S |  3 +--
 arch/x86/boot/compressed/head_64.S |  3 +--
 arch/x86/crypto/aesni-intel_asm.S  |  4 +---
 arch/x86/lib/memcpy_64.S           | 10 +++++-----
 arch/x86/lib/memmove_64.S          |  4 ++--
 arch/x86/lib/memset_64.S           |  6 +++---
 6 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 659fad53ca82..3b354eb9516d 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -152,14 +152,13 @@ SYM_FUNC_END(startup_32)
 
 #ifdef CONFIG_EFI_STUB
 SYM_FUNC_START(efi32_stub_entry)
-SYM_FUNC_START_ALIAS(efi_stub_entry)
 	add	$0x4, %esp
 	movl	8(%esp), %esi	/* save boot_params pointer */
 	call	efi_main
 	/* efi_main returns the possibly relocated address of startup_32 */
 	jmp	*%eax
 SYM_FUNC_END(efi32_stub_entry)
-SYM_FUNC_END_ALIAS(efi_stub_entry)
+SYM_FUNC_ALIAS(efi_stub_entry, efi32_stub_entry)
 #endif
 
 	.text
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index fd9441f40457..dea95301196b 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -535,7 +535,6 @@ SYM_CODE_END(startup_64)
 #ifdef CONFIG_EFI_STUB
 	.org 0x390
 SYM_FUNC_START(efi64_stub_entry)
-SYM_FUNC_START_ALIAS(efi_stub_entry)
 	and	$~0xf, %rsp			/* realign the stack */
 	movq	%rdx, %rbx			/* save boot_params pointer */
 	call	efi_main
@@ -543,7 +542,7 @@ SYM_FUNC_START_ALIAS(efi_stub_entry)
 	leaq	rva(startup_64)(%rax), %rax
 	jmp	*%rax
 SYM_FUNC_END(efi64_stub_entry)
-SYM_FUNC_END_ALIAS(efi_stub_entry)
+SYM_FUNC_ALIAS(efi_stub_entry, efi64_stub_entry)
 #endif
 
 	.text
diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index 363699dd7220..837c1e0aa021 100644
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -1751,8 +1751,6 @@ SYM_FUNC_END(aesni_gcm_finalize)
 
 #endif
 
-
-SYM_FUNC_START_LOCAL_ALIAS(_key_expansion_128)
 SYM_FUNC_START_LOCAL(_key_expansion_256a)
 	pshufd $0b11111111, %xmm1, %xmm1
 	shufps $0b00010000, %xmm0, %xmm4
@@ -1764,7 +1762,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_256a)
 	add $0x10, TKEYP
 	RET
 SYM_FUNC_END(_key_expansion_256a)
-SYM_FUNC_END_ALIAS(_key_expansion_128)
+SYM_FUNC_ALIAS_LOCAL(_key_expansion_128, _key_expansion_256a)
 
 SYM_FUNC_START_LOCAL(_key_expansion_192a)
 	pshufd $0b01010101, %xmm1, %xmm1
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 59cf2343f3d9..d0d7b9bc6cad 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -27,8 +27,7 @@
  * Output:
  * rax original destination
  */
-SYM_FUNC_START_ALIAS(__memcpy)
-SYM_FUNC_START_WEAK(memcpy)
+SYM_FUNC_START(__memcpy)
 	ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
 		      "jmp memcpy_erms", X86_FEATURE_ERMS
 
@@ -40,11 +39,12 @@ SYM_FUNC_START_WEAK(memcpy)
 	movl %edx, %ecx
 	rep movsb
 	RET
-SYM_FUNC_END(memcpy)
-SYM_FUNC_END_ALIAS(__memcpy)
-EXPORT_SYMBOL(memcpy)
+SYM_FUNC_END(__memcpy)
 EXPORT_SYMBOL(__memcpy)
 
+SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+EXPORT_SYMBOL(memcpy)
+
 /*
  * memcpy_erms() - enhanced fast string memcpy. This is faster and
  * simpler than memcpy. Use memcpy_erms when possible.
diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index 50ea390df712..d83cba364e31 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -24,7 +24,6 @@
  * Output:
  * rax: dest
  */
-SYM_FUNC_START_WEAK(memmove)
 SYM_FUNC_START(__memmove)
 
 	mov %rdi, %rax
@@ -207,6 +206,7 @@ SYM_FUNC_START(__memmove)
 13:
 	RET
 SYM_FUNC_END(__memmove)
-SYM_FUNC_END_ALIAS(memmove)
 EXPORT_SYMBOL(__memmove)
+
+SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
 EXPORT_SYMBOL(memmove)
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index d624f2bc42f1..fc9ffd3ff3b2 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -17,7 +17,6 @@
  *
  * rax   original destination
  */
-SYM_FUNC_START_WEAK(memset)
 SYM_FUNC_START(__memset)
 	/*
 	 * Some CPUs support enhanced REP MOVSB/STOSB feature. It is recommended
@@ -42,10 +41,11 @@ SYM_FUNC_START(__memset)
 	movq %r9,%rax
 	RET
 SYM_FUNC_END(__memset)
-SYM_FUNC_END_ALIAS(memset)
-EXPORT_SYMBOL(memset)
 EXPORT_SYMBOL(__memset)
 
+SYM_FUNC_ALIAS_WEAK(memset, __memset)
+EXPORT_SYMBOL(memset)
+
 /*
  * ISO C memset - set a memory block to a byte value. This function uses
  * enhanced rep stosb to override the fast string function.
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 9+ messages in thread
* [PATCH v3 4/5] linkage: remove SYM_FUNC_{START,END}_ALIAS()
  2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
                   ` (2 preceding siblings ...)
  2022-02-11 15:14 ` [PATCH v3 3/5] x86: " Mark Rutland
@ 2022-02-11 15:14 ` Mark Rutland
  2022-02-11 15:14 ` [PATCH v3 5/5] tools: update x86 string routines Mark Rutland
  2022-02-16  6:00 ` [PATCH v3 0/5] linkage: better symbol aliasing Josh Poimboeuf
  5 siblings, 0 replies; 9+ messages in thread
From: Mark Rutland @ 2022-02-11 15:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: acme, ardb, bp, broonie, catalin.marinas, dave.hansen, jpoimboe,
	jslaby, linux-arm-kernel, mark.rutland, mingo, ndesaulniers,
	peterz, tglx, will

Now that all aliases are defined using SYM_FUNC_ALIAS(), remove the old
SYM_FUNC_{START,END}_ALIAS() macros.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
 Documentation/asm-annotations.rst | 13 -------------
 include/linux/linkage.h           | 30 ------------------------------
 2 files changed, 43 deletions(-)

diff --git a/Documentation/asm-annotations.rst b/Documentation/asm-annotations.rst
index 4868b58c60fb..a64f2ca469d4 100644
--- a/Documentation/asm-annotations.rst
+++ b/Documentation/asm-annotations.rst
@@ -142,19 +142,6 @@ denoting a range of code via ``SYM_*_START/END`` annotations.
   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)
-        ... asm insns ...
-    SYM_FUNC_END(memset)
-    SYM_FUNC_END_ALIAS(__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_CODE_START`` and ``SYM_CODE_START_LOCAL`` should be used only in
   special cases -- if you know what you are doing. This is used exclusively
   for interrupt handlers and similar where the calling convention is not the C
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index aca8f5cb9c3c..bee482e956b4 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -211,30 +211,8 @@
 	SYM_ENTRY(name, linkage, SYM_A_NONE)
 #endif
 
-/*
- * SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for one
- * function
- */
-#ifndef SYM_FUNC_START_LOCAL_ALIAS
-#define SYM_FUNC_START_LOCAL_ALIAS(name)		\
-	SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
-#endif
-
-/*
- * SYM_FUNC_START_ALIAS -- use where there are two global names for one
- * function
- */
-#ifndef SYM_FUNC_START_ALIAS
-#define SYM_FUNC_START_ALIAS(name)			\
-	SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
-#endif
-
 /* SYM_FUNC_START -- use for global functions */
 #ifndef SYM_FUNC_START
-/*
- * The same as SYM_FUNC_START_ALIAS, but we will need to distinguish these two
- * later.
- */
 #define SYM_FUNC_START(name)				\
 	SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
 #endif
@@ -247,7 +225,6 @@
 
 /* SYM_FUNC_START_LOCAL -- use for local functions */
 #ifndef SYM_FUNC_START_LOCAL
-/* the same as SYM_FUNC_START_LOCAL_ALIAS, see comment near SYM_FUNC_START */
 #define SYM_FUNC_START_LOCAL(name)			\
 	SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
 #endif
@@ -270,18 +247,11 @@
 	SYM_START(name, SYM_L_WEAK, SYM_A_NONE)
 #endif
 
-/* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */
-#ifndef SYM_FUNC_END_ALIAS
-#define SYM_FUNC_END_ALIAS(name)			\
-	SYM_END(name, SYM_T_FUNC)
-#endif
-
 /*
  * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START,
  * SYM_FUNC_START_WEAK, ...
  */
 #ifndef SYM_FUNC_END
-/* the same as SYM_FUNC_END_ALIAS, see comment near SYM_FUNC_START */
 #define SYM_FUNC_END(name)				\
 	SYM_END(name, SYM_T_FUNC)
 #endif
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 9+ messages in thread
* [PATCH v3 5/5] tools: update x86 string routines
  2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
                   ` (3 preceding siblings ...)
  2022-02-11 15:14 ` [PATCH v3 4/5] linkage: remove SYM_FUNC_{START,END}_ALIAS() Mark Rutland
@ 2022-02-11 15:14 ` Mark Rutland
  2022-02-16  5:59   ` Josh Poimboeuf
  2022-02-16  6:00 ` [PATCH v3 0/5] linkage: better symbol aliasing Josh Poimboeuf
  5 siblings, 1 reply; 9+ messages in thread
From: Mark Rutland @ 2022-02-11 15:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: acme, ardb, bp, broonie, catalin.marinas, dave.hansen, jpoimboe,
	jslaby, linux-arm-kernel, mark.rutland, mingo, ndesaulniers,
	peterz, tglx, will

When building the perf tool the build system complains that the x86
string routines are out-of-date:

| Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
| diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
| Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
| diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

This is due to the way the asm-annotations for symbol aliasing were
reworked, which should have no functional/performance impact.

Import the latest versions, adding the new style SYM_FUNC_ALIAS(),
SYM_FUNC_ALIAS_LOAD(), SYM_FUNC_ALIAS_WEAK() macros into the perf
<linux/linkage.h> header. The old style SYM_FUNC_START_ALIAS() and
SYM_FUNC_END_ALIAS() macros are removed.

Other than removing the build-time warning, there should be no
functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
---
 tools/arch/x86/lib/memcpy_64.S          | 10 +++---
 tools/arch/x86/lib/memset_64.S          |  6 ++--
 tools/perf/util/include/linux/linkage.h | 46 ++++++++++++++++++-------
 3 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 59cf2343f3d9..d0d7b9bc6cad 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -27,8 +27,7 @@
  * Output:
  * rax original destination
  */
-SYM_FUNC_START_ALIAS(__memcpy)
-SYM_FUNC_START_WEAK(memcpy)
+SYM_FUNC_START(__memcpy)
 	ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
 		      "jmp memcpy_erms", X86_FEATURE_ERMS
 
@@ -40,11 +39,12 @@ SYM_FUNC_START_WEAK(memcpy)
 	movl %edx, %ecx
 	rep movsb
 	RET
-SYM_FUNC_END(memcpy)
-SYM_FUNC_END_ALIAS(__memcpy)
-EXPORT_SYMBOL(memcpy)
+SYM_FUNC_END(__memcpy)
 EXPORT_SYMBOL(__memcpy)
 
+SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+EXPORT_SYMBOL(memcpy)
+
 /*
  * memcpy_erms() - enhanced fast string memcpy. This is faster and
  * simpler than memcpy. Use memcpy_erms when possible.
diff --git a/tools/arch/x86/lib/memset_64.S b/tools/arch/x86/lib/memset_64.S
index d624f2bc42f1..fc9ffd3ff3b2 100644
--- a/tools/arch/x86/lib/memset_64.S
+++ b/tools/arch/x86/lib/memset_64.S
@@ -17,7 +17,6 @@
  *
  * rax   original destination
  */
-SYM_FUNC_START_WEAK(memset)
 SYM_FUNC_START(__memset)
 	/*
 	 * Some CPUs support enhanced REP MOVSB/STOSB feature. It is recommended
@@ -42,10 +41,11 @@ SYM_FUNC_START(__memset)
 	movq %r9,%rax
 	RET
 SYM_FUNC_END(__memset)
-SYM_FUNC_END_ALIAS(memset)
-EXPORT_SYMBOL(memset)
 EXPORT_SYMBOL(__memset)
 
+SYM_FUNC_ALIAS_WEAK(memset, __memset)
+EXPORT_SYMBOL(memset)
+
 /*
  * ISO C memset - set a memory block to a byte value. This function uses
  * enhanced rep stosb to override the fast string function.
diff --git a/tools/perf/util/include/linux/linkage.h b/tools/perf/util/include/linux/linkage.h
index 5acf053fca7d..b97d2e60edeb 100644
--- a/tools/perf/util/include/linux/linkage.h
+++ b/tools/perf/util/include/linux/linkage.h
@@ -50,16 +50,18 @@
 #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_FUNC_START_ALIAS -- use where there are two global names for one
- * function
- */
-#ifndef SYM_FUNC_START_ALIAS
-#define SYM_FUNC_START_ALIAS(name)			\
-	SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
+/* 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 -- use for global functions */
@@ -79,12 +81,6 @@
 	SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
 #endif
 
-/* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */
-#ifndef SYM_FUNC_END_ALIAS
-#define SYM_FUNC_END_ALIAS(name)			\
-	SYM_END(name, SYM_T_FUNC)
-#endif
-
 /* SYM_FUNC_START_WEAK -- use for weak functions */
 #ifndef SYM_FUNC_START_WEAK
 #define SYM_FUNC_START_WEAK(name)			\
@@ -101,4 +97,28 @@
 	SYM_END(name, SYM_T_FUNC)
 #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 -- 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_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_ */
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 9+ messages in thread
* Re: [PATCH v3 5/5] tools: update x86 string routines
  2022-02-11 15:14 ` [PATCH v3 5/5] tools: update x86 string routines Mark Rutland
@ 2022-02-16  5:59   ` Josh Poimboeuf
  2022-02-16 14:15     ` Mark Rutland
  0 siblings, 1 reply; 9+ messages in thread
From: Josh Poimboeuf @ 2022-02-16  5:59 UTC (permalink / raw)
  To: Mark Rutland
  Cc: linux-kernel, acme, ardb, bp, broonie, catalin.marinas,
	dave.hansen, jslaby, linux-arm-kernel, mingo, ndesaulniers,
	peterz, tglx, will

On Fri, Feb 11, 2022 at 03:14:45PM +0000, Mark Rutland wrote:
> When building the perf tool the build system complains that the x86
> string routines are out-of-date:
> 
> | Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
> | diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
> | Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
> | diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S
> 
> This is due to the way the asm-annotations for symbol aliasing were
> reworked, which should have no functional/performance impact.
> 
> Import the latest versions, adding the new style SYM_FUNC_ALIAS(),
> SYM_FUNC_ALIAS_LOAD(), SYM_FUNC_ALIAS_WEAK() macros into the perf
> <linux/linkage.h> header. The old style SYM_FUNC_START_ALIAS() and
> SYM_FUNC_END_ALIAS() macros are removed.
> 
> Other than removing the build-time warning, there should be no
> functional change as a result of this patch.

These changes should probably be squashed with their corresponding
original kernel changes to avoid breaking bisection for the warnings.
And it helps to keep the interdependent changes together.

-- 
Josh


^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [PATCH v3 0/5] linkage: better symbol aliasing
  2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
                   ` (4 preceding siblings ...)
  2022-02-11 15:14 ` [PATCH v3 5/5] tools: update x86 string routines Mark Rutland
@ 2022-02-16  6:00 ` Josh Poimboeuf
  5 siblings, 0 replies; 9+ messages in thread
From: Josh Poimboeuf @ 2022-02-16  6:00 UTC (permalink / raw)
  To: Mark Rutland
  Cc: linux-kernel, acme, ardb, bp, broonie, catalin.marinas,
	dave.hansen, jslaby, linux-arm-kernel, mingo, ndesaulniers,
	peterz, tglx, will

On Fri, Feb 11, 2022 at 03:14:40PM +0000, Mark Rutland wrote:
> This series aims to make symbol aliasing simpler and more consistent.
> The basic idea is to replace SYM_FUNC_START_ALIAS(alias) and
> SYM_FUNC_END_ALIAS(alias) with a new SYM_FUNC_ALIAS(alias, name), so
> that e.g.
> 
>     SYM_FUNC_START(func)
>     SYM_FUNC_START_ALIAS(alias1)
>     SYM_FUNC_START_ALIAS(alias2)
>         ... asm insns ...
>     SYM_FUNC_END(func)
>     SYM_FUNC_END_ALIAS(alias1)
>     SYM_FUNC_END_ALIAS(alias2)
>     EXPORT_SYMBOL(alias1)
>     EXPORT_SYMBOL(alias2)
> 
> ... can become:
> 
>     SYM_FUNC_START(name)
>         ... asm insns ...
>     SYM_FUNC_END(name)
> 
>     SYM_FUNC_ALIAS(alias1, func)
>     EXPORT_SYMBOL(alias1)
> 
>     SYM_FUNC_ALIAS(alias2, func)
>     EXPORT_SYMBOL(alias2)
> 
> This avoids repetition and hopefully make it easier to ensure
> consistency (e.g. so each function has a single canonical name and
> associated metadata).

Nice!

Other than the minor comment to squash the synced header changes,

Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

-- 
Josh


^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [PATCH v3 5/5] tools: update x86 string routines
  2022-02-16  5:59   ` Josh Poimboeuf
@ 2022-02-16 14:15     ` Mark Rutland
  0 siblings, 0 replies; 9+ messages in thread
From: Mark Rutland @ 2022-02-16 14:15 UTC (permalink / raw)
  To: Josh Poimboeuf
  Cc: linux-kernel, acme, ardb, bp, broonie, catalin.marinas,
	dave.hansen, jslaby, linux-arm-kernel, mingo, ndesaulniers,
	peterz, tglx, will

On Tue, Feb 15, 2022 at 09:59:52PM -0800, Josh Poimboeuf wrote:
> On Fri, Feb 11, 2022 at 03:14:45PM +0000, Mark Rutland wrote:
> > When building the perf tool the build system complains that the x86
> > string routines are out-of-date:
> > 
> > | Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
> > | diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
> > | Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
> > | diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S
> > 
> > This is due to the way the asm-annotations for symbol aliasing were
> > reworked, which should have no functional/performance impact.
> > 
> > Import the latest versions, adding the new style SYM_FUNC_ALIAS(),
> > SYM_FUNC_ALIAS_LOAD(), SYM_FUNC_ALIAS_WEAK() macros into the perf
> > <linux/linkage.h> header. The old style SYM_FUNC_START_ALIAS() and
> > SYM_FUNC_END_ALIAS() macros are removed.
> > 
> > Other than removing the build-time warning, there should be no
> > functional change as a result of this patch.
> 
> These changes should probably be squashed with their corresponding
> original kernel changes to avoid breaking bisection for the warnings.
> And it helps to keep the interdependent changes together.

Sure; done for v4.

Doing that highlighted a couple of fixups I failed to make to the
tools/perf/ copy; I've fixed those up.

Thanks,
Mark.

^ permalink raw reply	[flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-02-16 14:15 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-02-11 15:14 [PATCH v3 0/5] linkage: better symbol aliasing Mark Rutland
2022-02-11 15:14 ` [PATCH v3 1/5] linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}() Mark Rutland
2022-02-11 15:14 ` [PATCH v3 2/5] arm64: clean up symbol aliasing Mark Rutland
2022-02-11 15:14 ` [PATCH v3 3/5] x86: " Mark Rutland
2022-02-11 15:14 ` [PATCH v3 4/5] linkage: remove SYM_FUNC_{START,END}_ALIAS() Mark Rutland
2022-02-11 15:14 ` [PATCH v3 5/5] tools: update x86 string routines Mark Rutland
2022-02-16  5:59   ` Josh Poimboeuf
2022-02-16 14:15     ` Mark Rutland
2022-02-16  6:00 ` [PATCH v3 0/5] linkage: better symbol aliasing Josh Poimboeuf

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