On Tue, Aug 16, 2022 at 01:14:13PM +0200, Jiri Slaby wrote: > On 16. 08. 22, 13:04, Jiri Slaby wrote: > > On 15. 08. 22, 20:02, Greg Kroah-Hartman wrote: > > > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > > > > > [ Upstream commit 6c2f761dad7851d8088b91063ccaea3c970efe78 ] > > > > > > HW_TAGS KASAN skips zeroing page_alloc allocations backing vmalloc > > > mappings via __GFP_SKIP_ZERO. Instead, these pages are zeroed via > > > kasan_unpoison_vmalloc() by passing the KASAN_VMALLOC_INIT flag. > > > > > > The problem is that __kasan_unpoison_vmalloc() does not zero pages when > > > either kasan_vmalloc_enabled() or is_vmalloc_or_module_addr() fail. > > > > > > Thus: > > > > > > 1. Change __vmalloc_node_range() to only set KASAN_VMALLOC_INIT when > > > __GFP_SKIP_ZERO is set. > > > > > > 2. Change __kasan_unpoison_vmalloc() to always zero pages when the > > > KASAN_VMALLOC_INIT flag is set. > > > > > > 3. Add WARN_ON() asserts to check that KASAN_VMALLOC_INIT cannot be set > > > in other early return paths of __kasan_unpoison_vmalloc(). > > > > > > Also clean up the comment in __kasan_unpoison_vmalloc. > > > > > > Link: https://lkml.kernel.org/r/4bc503537efdc539ffc3f461c1b70162eea31cf6.1654798516.git.andreyknvl@xxxxxxxxxx > > > Fixes: 23689e91fb22 ("kasan, vmalloc: add vmalloc tagging for HW_TAGS") > > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > > Cc: Marco Elver <elver@xxxxxxxxxx> > > > Cc: Alexander Potapenko <glider@xxxxxxxxxx> > > > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > > > Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> > > > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > > --- > > > mm/kasan/hw_tags.c | 32 +++++++++++++++++++++++--------- > > > mm/vmalloc.c | 10 +++++----- > > > 2 files changed, 28 insertions(+), 14 deletions(-) > > > > > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > > > index 9e1b6544bfa8..9ad8eff71b28 100644 > > > --- a/mm/kasan/hw_tags.c > > > +++ b/mm/kasan/hw_tags.c > > > @@ -257,27 +257,37 @@ static void unpoison_vmalloc_pages(const void > > > *addr, u8 tag) > > > } > > > } > > > +static void init_vmalloc_pages(const void *start, unsigned long size) > > > +{ > > > + const void *addr; > > > + > > > + for (addr = start; addr < start + size; addr += PAGE_SIZE) { > > > + struct page *page = virt_to_page(addr); > > > + > > > + clear_highpage_kasan_tagged(page); > > > > This breaks build on aarch64: > > > mm/kasan/hw_tags.c: In function 'init_vmalloc_pages': > > > mm/kasan/hw_tags.c:267:17: error: implicit declaration of function > > > 'clear_highpage_kasan_tagged' > > > [-Werror=implicit-function-declaration] > > Which translates into: this is missing: > commit d9da8f6cf55eeca642c021912af1890002464c64 > Author: Andrey Konovalov <andreyknvl@xxxxxxxxx> > Date: Thu Jun 9 20:18:46 2022 +0200 > > mm: introduce clear_highpage_kasan_tagged Thanks, now added to both 5.18.y and 5.19.y. I'll push out some -rc2 releases with this in it so it can get some testing. greg k-h
