linux-kernel - [PATCH] alloc_tag: remove empty module tag section

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20250610162258.324645-1-cachen@purestorage.com>
Date: Tue, 10 Jun 2025 10:22:58 -0600
From: Casey Chen <cachen@...estorage.com>
To: akpm@...ux-foundation.org
Cc: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	linux-modules@...r.kernel.org,
	linux-arch@...r.kernel.org,
	surenb@...gle.com,
	kent.overstreet@...ux.dev,
	arnd@...db.de,
	mcgrof@...nel.org,
	pasha.tatashin@...een.com,
	yzhong@...estorage.com,
	Casey Chen <cachen@...estorage.com>
Subject: [PATCH] alloc_tag: remove empty module tag section

The empty MOD_CODETAG_SECTIONS() macro added an incomplete .data
section in module linker script, which caused symbol lookup tools
like gdb to misinterpret symbol addresses e.g., __ib_process_cq
incorrectly mapping to unrelated functions like below.

  (gdb) disas __ib_process_cq
  Dump of assembler code for function trace_event_fields_cq_schedule:

Removing the empty section restores proper symbol resolution and
layout, ensuring .data placement behaves as expected.

Fixes: 0db6f8d7820a ("alloc_tag: load module tags into separate contiguous memory")
       22d407b164ff ("lib: add allocation tagging support for memory allocation profiling")
Signed-off-by: Casey Chen <cachen@...estorage.com>
Reviewed-by: Yuanyuan Zhong <yzhong@...estorage.com>
Acked-by: Suren Baghdasaryan <surenb@...gle.com>
---
 include/asm-generic/codetag.lds.h | 6 ------
 scripts/module.lds.S              | 5 -----
 2 files changed, 11 deletions(-)

diff --git a/include/asm-generic/codetag.lds.h b/include/asm-generic/codetag.lds.h
index 372c320c5043..a45fe3d141a1 100644
--- a/include/asm-generic/codetag.lds.h
+++ b/include/asm-generic/codetag.lds.h
@@ -11,12 +11,6 @@
 #define CODETAG_SECTIONS()		\
 	SECTION_WITH_BOUNDARIES(alloc_tags)
 
-/*
- * Module codetags which aren't used after module unload, therefore have the
- * same lifespan as the module and can be safely unloaded with the module.
- */
-#define MOD_CODETAG_SECTIONS()
-
 #define MOD_SEPARATE_CODETAG_SECTION(_name)	\
 	.codetag.##_name : {			\
 		SECTION_WITH_BOUNDARIES(_name)	\
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 711c6e029936..c071ca4beedd 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -50,17 +50,12 @@ SECTIONS {
 	.data : {
 		*(.data .data.[0-9a-zA-Z_]*)
 		*(.data..L*)
-		MOD_CODETAG_SECTIONS()
 	}
 
 	.rodata : {
 		*(.rodata .rodata.[0-9a-zA-Z_]*)
 		*(.rodata..L*)
 	}
-#else
-	.data : {
-		MOD_CODETAG_SECTIONS()
-	}
 #endif
 	MOD_SEPARATE_CODETAG_SECTIONS()
 }
-- 
2.34.1