From e48a12e546ecbfb0718176037eae0ad60598a29a Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 13 Jul 2021 06:16:05 +0200 Subject: [PATCH] jump_labels: Mark __jump_label_transform() as __always_inlined to work around aggressive compiler un-inlining In randconfig testing, certain UBSAN and CC Kconfig combinations with GCC 10.3.0: CONFIG_X86_32=y CONFIG_CC_OPTIMIZE_FOR_SIZE=y CONFIG_UBSAN=y # CONFIG_UBSAN_TRAP is not set # CONFIG_UBSAN_BOUNDS is not set CONFIG_UBSAN_SHIFT=y # CONFIG_UBSAN_DIV_ZERO is not set CONFIG_UBSAN_UNREACHABLE=y CONFIG_UBSAN_BOOL=y # CONFIG_UBSAN_ENUM is not set # CONFIG_UBSAN_ALIGNMENT is not set # CONFIG_UBSAN_SANITIZE_ALL is not set ... produce this build warning (and build error if CONFIG_SECTION_MISMATCH_WARN_ONLY=y is set): WARNING: modpost: vmlinux.o(.text+0x4c1cc): Section mismatch in reference from the function __jump_label_transform() to the function .init.text:text_poke_early() The function __jump_label_transform() references the function __init text_poke_early(). This is often because __jump_label_transform lacks a __init annotation or the annotation of text_poke_early is wrong. ERROR: modpost: Section mismatches detected. The problem is that __jump_label_transform() gets uninlined by GCC, despite there being only a single local scope user of the 'static inline' function. Mark the function __always_inline instead, to work around this compiler bug/artifact. Signed-off-by: Ingo Molnar --- arch/x86/kernel/jump_label.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index 674906f..68f091b 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -79,9 +79,10 @@ __jump_label_patch(struct jump_entry *entry, enum jump_label_type type) return (struct jump_label_patch){.code = code, .size = size}; } -static inline void __jump_label_transform(struct jump_entry *entry, - enum jump_label_type type, - int init) +static __always_inline void +__jump_label_transform(struct jump_entry *entry, + enum jump_label_type type, + int init) { const struct jump_label_patch jlp = __jump_label_patch(entry, type); -- 2.7.4