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@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202407032306.gi9nZsBi-lkp@intel.com/ Signed-off-by: Suren Baghdasaryan surenb@google.com Cc: Kent Overstreet kent.overstreet@linux.dev Cc: stable@vger.kernel.org ---
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@google.com/
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