Mark alloc_tag_{save|restore} as always_inline to fix the following
modpost warnings:
WARNING: modpost: vmlinux: section mismatch in reference: alloc_tag_save+0x1c (section: .text.unlikely) -> initcall_level_names (section: .init.data)
WARNING: modpost: vmlinux: section mismatch in reference: alloc_tag_restore+0x3c (section: .text.unlikely) -> initcall_level_names (section: .init.data)
The warnings happen when these functions are called from an __init
function and they don't get inlined (remain in the .text section) while
the value returned by get_current() points into .init.data section.
Assuming get_current() always returns a valid address, this situation can
happen only during init stage and accessing .init.data from .text section
during that stage should pose no issues.
Fixes: 22d407b164ff ("lib: add allocation tagging support for memory allocation profiling")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202407032306.gi9nZsBi-lkp@xxxxxxxxx/
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
Changes since v1 [1]:
- Added the second patch to resolve follow-up warnings
- Expanded changelog description, per Andrew Morton
- CC'ed stable, per Andrew Morton
- Added Fixes tag, per Andrew Morton
[1] https://lore.kernel.org/all/20240703221520.4108464-1-surenb@xxxxxxxxxx/
include/linux/sched.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 61591ac6eab6..a5f4b48fca18 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2192,13 +2192,13 @@ static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
extern void sched_set_stop_task(int cpu, struct task_struct *stop);
#ifdef CONFIG_MEM_ALLOC_PROFILING
-static inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag)
+static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag)
{
swap(current->alloc_tag, tag);
return tag;
}
-static inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old)
+static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old)
{
#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n");
base-commit: 795c58e4c7fc6163d8fb9f2baa86cfe898fa4b19
--
2.45.2.803.g4e1b14247a-goog
