| Message ID | 20190307075124.3424302-1-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
| Series | page flags: prioritize kasan bits over last-cpuid | expand |
On Thu, Mar 7, 2019 at 8:51 AM Arnd Bergmann <arnd@arndb.de> wrote: > > 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. > > Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > include/linux/page-flags-layout.h | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h > index 1dda31825ec4..9bc0751e68b2 100644 > --- a/include/linux/page-flags-layout.h > +++ b/include/linux/page-flags-layout.h > @@ -76,21 +76,23 @@ > #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 > -#endif > > /* > * We are going to use the flags for the page to node mapping if its in > -- > 2.20.0 > Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Thanks!
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h index 1dda31825ec4..9bc0751e68b2 100644 --- a/include/linux/page-flags-layout.h +++ b/include/linux/page-flags-layout.h @@ -76,21 +76,23 @@ #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 -#endif /* * We are going to use the flags for the page to node mapping if its in
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. Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- include/linux/page-flags-layout.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) -- 2.20.0