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authorArnd Bergmann <arnd@arndb.de>2019-08-02 21:49:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-08-03 07:02:01 -0700
commitee38d94a0ad89890b770f6c876263cf9fcbfde84 (patch)
tree1edc9c9137d2412e35dc9f332dce76e1ff96e99d /include/linux
parentaf700eaed0564d5d3963a7a51cb0843629d7fe3d (diff)
page flags: prioritize kasan bits over last-cpuid
ARM64 randdconfig builds regularly run into a build error, especially when NUMA_BALANCING and SPARSEMEM are enabled but not SPARSEMEM_VMEMMAP: #error "KASAN: not enough bits in page flags for tag" The last-cpuid bits are already contitional on the available space, so the result of the calculation is a bit random on whether they were already left out or not. Adding the kasan tag bits before last-cpuid makes it much more likely to end up with a successful build here, and should be reliable for randconfig at least, as long as that does not randomize NR_CPUS or NODES_SHIFT but uses the defaults. In order for the modified check to not trigger in the x86 vdso32 code where all constants are wrong (building with -m32), enclose all the definitions with an #ifdef. [arnd@arndb.de: build fix] Link: http://lkml.kernel.org/r/CAK8P3a3Mno1SWTcuAOT0Wa9VS15pdU6EfnkxLbDpyS55yO04+g@mail.gmail.com Link: http://lkml.kernel.org/r/20190722115520.3743282-1-arnd@arndb.de Link: https://lore.kernel.org/lkml/20190618095347.3850490-1-arnd@arndb.de/ Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/page-flags-layout.h18
1 files changed, 11 insertions, 7 deletions
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
index 1dda31825ec4..71283739ffd2 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -32,6 +32,7 @@
#endif /* CONFIG_SPARSEMEM */
+#ifndef BUILD_VDSO32_64
/*
* page->flags layout:
*
@@ -76,20 +77,22 @@
#define LAST_CPUPID_SHIFT 0
#endif
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
+#ifdef CONFIG_KASAN_SW_TAGS
+#define KASAN_TAG_WIDTH 8
+#else
+#define KASAN_TAG_WIDTH 0
+#endif
+
+#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_CPUPID_SHIFT+KASAN_TAG_WIDTH \
+ <= BITS_PER_LONG - NR_PAGEFLAGS
#define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT
#else
#define LAST_CPUPID_WIDTH 0
#endif
-#ifdef CONFIG_KASAN_SW_TAGS
-#define KASAN_TAG_WIDTH 8
#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH+LAST_CPUPID_WIDTH+KASAN_TAG_WIDTH \
> BITS_PER_LONG - NR_PAGEFLAGS
-#error "KASAN: not enough bits in page flags for tag"
-#endif
-#else
-#define KASAN_TAG_WIDTH 0
+#error "Not enough bits in page flags"
#endif
/*
@@ -104,4 +107,5 @@
#define LAST_CPUPID_NOT_IN_PAGE_FLAGS
#endif
+#endif
#endif /* _LINUX_PAGE_FLAGS_LAYOUT */