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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	jpoimboe@redhat.com, brgerst@gmail.com, jiangshanlai@gmail.com,
	Andrew.Cooper3@citrix.com, mark.rutland@arm.com
Subject: [PATCH 5/6] linkage: Fix issue with missing symbol size
Date: Fri, 06 May 2022 14:14:36 +0200	[thread overview]
Message-ID: <20220506121631.437480085@infradead.org> (raw)
In-Reply-To: 20220506121431.563656641@infradead.org

Occasionally, typically when a function doesn't end with 'ret', an
alias on that function will have 0 size.

The difference between what GCC generates and our linkage magic, is
that GCC doesn't appear to provide .size for the alias'ed symbol at
all. And indeed, removing this directive cures the issue.

Additionally, GCC also doesn't emit .type for alias symbols either, so
also omit that.

Fixes: e0891269a8c2 ("linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}()")
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 include/linux/linkage.h |   15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -171,12 +171,9 @@
 
 /* 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
+#define SYM_ALIAS(alias, name, linkage)			\
+	linkage(alias) ASM_NL				\
+	.set alias, name ASM_NL
 #endif
 
 /* === code annotations === */
@@ -261,7 +258,7 @@
  */
 #ifndef SYM_FUNC_ALIAS
 #define SYM_FUNC_ALIAS(alias, name)					\
-	SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_GLOBAL)
+	SYM_ALIAS(alias, name, SYM_L_GLOBAL)
 #endif
 
 /*
@@ -269,7 +266,7 @@
  */
 #ifndef SYM_FUNC_ALIAS_LOCAL
 #define SYM_FUNC_ALIAS_LOCAL(alias, name)				\
-	SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_LOCAL)
+	SYM_ALIAS(alias, name, SYM_L_LOCAL)
 #endif
 
 /*
@@ -277,7 +274,7 @@
  */
 #ifndef SYM_FUNC_ALIAS_WEAK
 #define SYM_FUNC_ALIAS_WEAK(alias, name)				\
-	SYM_ALIAS(alias, name, SYM_T_FUNC, SYM_L_WEAK)
+	SYM_ALIAS(alias, name, SYM_L_WEAK)
 #endif
 
 /* SYM_CODE_START -- use for non-C (special) functions */



  parent reply	other threads:[~2022-05-06 12:20 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-06 12:14 [PATCH 0/6] x86: Various cleanups and fixes Peter Zijlstra
2022-05-06 12:14 ` [PATCH 1/6] x86/mm: Simplify RESERVE_BRK() Peter Zijlstra
2022-05-06 15:09   ` [tip: x86/asm] " tip-bot2 for Josh Poimboeuf
2022-05-06 12:14 ` [PATCH 2/6] x86/entry: Simplify entry_INT80_compat() Peter Zijlstra
2022-05-06 15:09   ` [tip: x86/asm] " tip-bot2 for Linus Torvalds
2022-05-06 12:14 ` [PATCH 3/6] x86/entry: Use PUSH_AND_CLEAR_REGS for compat Peter Zijlstra
2022-05-06 15:09   ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
2022-05-07  2:54   ` [PATCH 3/6] " Lai Jiangshan
2022-05-19 16:24   ` Guenter Roeck
2022-05-19 17:00     ` Peter Zijlstra
2022-05-19 17:11       ` Josh Poimboeuf
2022-05-19 17:35         ` Josh Poimboeuf
2022-05-20  1:11           ` Lai Jiangshan
2022-05-20  2:46             ` Guenter Roeck
2022-05-20 15:55             ` Josh Poimboeuf
2022-05-06 12:14 ` [PATCH 4/6] x86/entry: Remove skip_r11rcx Peter Zijlstra
2022-05-06 15:09   ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
2022-05-07  2:52   ` [PATCH 4/6] " Lai Jiangshan
2022-05-06 12:14 ` Peter Zijlstra [this message]
2022-05-06 15:08   ` [tip: x86/asm] linkage: Fix issue with missing symbol size tip-bot2 for Peter Zijlstra
2022-05-06 12:14 ` [PATCH 6/6] objtool: Fix STACK_FRAME_NON_STANDARD reloc type Peter Zijlstra
2022-05-06 15:08   ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
2022-05-06 16:05   ` [PATCH 6/6] " Josh Poimboeuf
2022-05-06 20:26   ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra

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