From: Casey Chen <cachen@purestorage.com>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-modules@vger.kernel.org, linux-arch@vger.kernel.org,
surenb@google.com, kent.overstreet@linux.dev, arnd@arndb.de,
mcgrof@kernel.org, pasha.tatashin@soleen.com,
yzhong@purestorage.com, Casey Chen <cachen@purestorage.com>
Subject: [PATCH] alloc_tag: remove empty module tag section
Date: Tue, 10 Jun 2025 10:22:58 -0600 [thread overview]
Message-ID: <20250610162258.324645-1-cachen@purestorage.com> (raw)
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@purestorage.com>
Reviewed-by: Yuanyuan Zhong <yzhong@purestorage.com>
Acked-by: Suren Baghdasaryan <surenb@google.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
next reply other threads:[~2025-06-10 16:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-10 16:22 Casey Chen [this message]
2025-06-17 9:27 ` Petr Pavlu
2025-06-17 15:05 ` Suren Baghdasaryan
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