[RFC PATCH 01/15] arch: x86: remove MAX_ORDER exceeding SECTION_SIZE check for 32bit vdso.
From: Zi Yan <hidden>
Date: 2021-08-05 19:03:48
Also in:
lkml
Subsystem:
memory management - core, memory management - mglru (multi-gen lru), the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
From: Zi Yan <ziy@nvidia.com> For x86_64, 32bit vdso is compiled for compatibility reason and 32bit SECTION_SIZE_BITS value is used during compilation. It causes compilation time error when MAX_ORDER is increased in the 64bit environment even if it is OK for 64bit SECTION_SIZE_BITS. Remove the check during 32bit vdso compilation. The check still exists during the compilation of other kernel components. Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org --- arch/x86/entry/vdso/Makefile | 1 + include/linux/mmzone.h | 3 +++ 2 files changed, 4 insertions(+)
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 05c4abc2fdfd..cad339136ed1 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile@@ -156,6 +156,7 @@ KBUILD_CFLAGS_32 += -fno-stack-protector KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls) KBUILD_CFLAGS_32 += -fno-omit-frame-pointer KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING +KBUILD_CFLAGS_32 += -DNO_MAX_ORDER_CHECK ifdef CONFIG_RETPOLINE ifneq ($(RETPOLINE_VDSO_CFLAGS),)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6a1d79d84675..c1d914a72489 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h@@ -1245,9 +1245,12 @@ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, #define SECTION_BLOCKFLAGS_BITS \ ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) +/* NO_MAX_ORDER_CHECK when compiling x64 32bit VDSO for 64bit system */ +#ifndef NO_MAX_ORDER_CHECK #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS #error Allocator MAX_ORDER exceeds SECTION_SIZE #endif +#endif /* NO_MAX_ORDER_CHECK */ static inline unsigned long pfn_to_section_nr(unsigned long pfn) {
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2.30.2