[alternative-merged] alloc_tag-work-around-clang-14-issue-with-__builtin_object_size.patch removed from -mm tree

[alternative-merged] alloc_tag-work-around-clang-14-issue-with-__builtin_object_size.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: alloc_tag: work around clang-14 build issue with __builtin_object_size()
has been removed from the -mm tree.  Its filename was
     alloc_tag-work-around-clang-14-issue-with-__builtin_object_size.patch

This patch was dropped because an alternative patch was or shall be merged

------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: alloc_tag: work around clang-14 build issue with __builtin_object_size()
Date: Sat, 1 Feb 2025 12:05:03 -0800

Additional condition in the allocation hooks causes Clang version 14
(tested on 14.0.6) to treat the allocated object size as unknown at
compile-time (__builtin_object_size(obj, 1) returns -1) even though both
branches of that condition yield the same result.  Other versions of Clang
(tested with 13.0.1, 15.0.7, 16.0.6 and 17.0.6) compile the same code
without issues.  Add build-time Clang version check which removes this
condition and effectively restores the unconditional tag store/restore
flow when compiled with clang-14.

Link: https://lkml.kernel.org/r/20250201200503.2532357-1-surenb@google.com
Fixes: 07438779313c ("alloc_tag: avoid current->alloc_tag manipulations when profiling is disabled")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501310832.kiAeOt2z-lkp@intel.com/
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/alloc_tag.h |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

--- a/include/linux/alloc_tag.h~alloc_tag-work-around-clang-14-issue-with-__builtin_object_size
+++ a/include/linux/alloc_tag.h
@@ -222,10 +222,23 @@ static inline void alloc_tag_sub(union c
 
 #endif /* CONFIG_MEM_ALLOC_PROFILING */
 
+/* See https://lore.kernel.org/all/202501310832.kiAeOt2z-lkp@intel.com/ */
+#if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION >= 140000 && CONFIG_CLANG_VERSION < 150000
+static inline bool store_current_tag(void)
+{
+	return true;
+}
+#else
+static inline bool store_current_tag(void)
+{
+	return mem_alloc_profiling_enabled();
+}
+#endif
+
 #define alloc_hooks_tag(_tag, _do_alloc)				\
 ({									\
 	typeof(_do_alloc) _res;						\
-	if (mem_alloc_profiling_enabled()) {				\
+	if (store_current_tag()) {					\
 		struct alloc_tag * __maybe_unused _old;			\
 		_old = alloc_tag_save(_tag);				\
 		_res = _do_alloc;					\
_

Patches currently in -mm which might be from surenb@google.com are

mm-avoid-extra-mem_alloc_profiling_enabled-checks.patch
alloc_tag-uninline-code-gated-by-mem_alloc_profiling_key-in-slab-allocator.patch
alloc_tag-uninline-code-gated-by-mem_alloc_profiling_key-in-page-allocator.patch
mm-introduce-vma_start_read_locked_nested-helpers.patch
mm-move-per-vma-lock-into-vm_area_struct.patch
mm-mark-vma-as-detached-until-its-added-into-vma-tree.patch
mm-introduce-vma_iter_store_attached-to-use-with-attached-vmas.patch
mm-mark-vmas-detached-upon-exit.patch
types-move-struct-rcuwait-into-typesh.patch
mm-allow-vma_start_read_locked-vma_start_read_locked_nested-to-fail.patch
mm-move-mmap_init_lock-out-of-the-header-file.patch
mm-uninline-the-main-body-of-vma_start_write.patch
refcount-provide-ops-for-cases-when-objects-memory-can-be-reused.patch
refcount-provide-ops-for-cases-when-objects-memory-can-be-reused-fix.patch
refcount-introduce-__refcount_addinc_not_zero_limited_acquire.patch
mm-replace-vm_lock-and-detached-flag-with-a-reference-count.patch
mm-move-lesser-used-vma_area_struct-members-into-the-last-cacheline.patch
mm-debug-print-vm_refcnt-state-when-dumping-the-vma.patch
mm-remove-extra-vma_numab_state_init-call.patch
mm-prepare-lock_vma_under_rcu-for-vma-reuse-possibility.patch
mm-make-vma-cache-slab_typesafe_by_rcu.patch
mm-make-vma-cache-slab_typesafe_by_rcu-fix.patch
docs-mm-document-latest-changes-to-vm_lock.patch