The patch titled
Subject: page flags: prioritize kasan bits over last-cpuid
has been removed from the -mm tree. Its filename was
page-flags-prioritize-kasan-bits-over-last-cpuid.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: 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@xxxxxxxx: build fix]
Link: http://lkml.kernel.org/r/CAK8P3a3Mno1SWTcuAOT0Wa9VS15pdU6EfnkxLbDpyS55yO04+g@xxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190722115520.3743282-1-arnd@xxxxxxxx
Link: https://lore.kernel.org/lkml/20190618095347.3850490-1-arnd@xxxxxxxx/
Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/mips/vdso/vdso.h | 1 +
include/linux/page-flags-layout.h | 18 +++++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
--- a/arch/mips/vdso/vdso.h~page-flags-prioritize-kasan-bits-over-last-cpuid
+++ a/arch/mips/vdso/vdso.h
@@ -9,6 +9,7 @@
#if _MIPS_SIM != _MIPS_SIM_ABI64 && defined(CONFIG_64BIT)
/* Building 32-bit VDSO for the 64-bit kernel. Fake a 32-bit Kconfig. */
+#define BUILD_VDSO32_64
#undef CONFIG_64BIT
#define CONFIG_32BIT 1
#ifndef __ASSEMBLY__
--- a/include/linux/page-flags-layout.h~page-flags-prioritize-kasan-bits-over-last-cpuid
+++ a/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 */
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
mm-sparse-fix-memory-leak-of-sparsemap_buf-in-aliged-memory-fix.patch
