| Message ID | 20230412145300.3651840-1-glider@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush() | expand |
Hi Alexander,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
url: https://github.com/intel-lab-lkp/linux/commits/Alexander-Potapenko/mm-kmsan-handle-alloc-failures-in-kmsan_ioremap_page_range/20230412-225414
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230412145300.3651840-1-glider%40google.com
patch subject: [PATCH 1/2] mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()
config: i386-randconfig-a013 (https://download.01.org/0day-ci/archive/20230413/202304130223.epEIvA1E-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/f8f0837563234abfae564b24278879d42d52a6e8
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Alexander-Potapenko/mm-kmsan-handle-alloc-failures-in-kmsan_ioremap_page_range/20230412-225414
git checkout f8f0837563234abfae564b24278879d42d52a6e8
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 prepare
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304130223.epEIvA1E-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from arch/x86/kernel/asm-offsets.c:14:
In file included from include/linux/suspend.h:5:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:13:
In file included from include/linux/blk_types.h:10:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:9:
>> include/linux/kmsan.h:291:1: error: non-void function does not return a value [-Werror,-Wreturn-type]
}
^
1 error generated.
make[2]: *** [scripts/Makefile.build:114: arch/x86/kernel/asm-offsets.s] Error 1
make[2]: Target 'prepare' not remade because of errors.
make[1]: *** [Makefile:1286: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:226: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +291 include/linux/kmsan.h
68ef169a1dd20d Alexander Potapenko 2022-09-15 284
f8f0837563234a Alexander Potapenko 2023-04-12 285 static inline int kmsan_vmap_pages_range_noflush(unsigned long start,
b073d7f8aee4eb Alexander Potapenko 2022-09-15 286 unsigned long end,
b073d7f8aee4eb Alexander Potapenko 2022-09-15 287 pgprot_t prot,
b073d7f8aee4eb Alexander Potapenko 2022-09-15 288 struct page **pages,
b073d7f8aee4eb Alexander Potapenko 2022-09-15 289 unsigned int page_shift)
b073d7f8aee4eb Alexander Potapenko 2022-09-15 290 {
b073d7f8aee4eb Alexander Potapenko 2022-09-15 @291 }
b073d7f8aee4eb Alexander Potapenko 2022-09-15 292
On Thu, 13 Apr 2023 02:27:19 +0800 kernel test robot <lkp@intel.com> wrote: > Hi Alexander, > > kernel test robot noticed the following build errors: > > [auto build test ERROR on akpm-mm/mm-everything] > > >> include/linux/kmsan.h:291:1: error: non-void function does not return a value [-Werror,-Wreturn-type] Thanks, I'll do this: --- a/include/linux/kmsan.h~mm-kmsan-handle-alloc-failures-in-kmsan_ioremap_page_range-fix +++ a/include/linux/kmsan.h @@ -289,6 +289,7 @@ static inline int kmsan_vmap_pages_range struct page **pages, unsigned int page_shift) { + return 0; } static inline void kmsan_vunmap_range_noflush(unsigned long start,
On Wed, Apr 12, 2023 at 11:06 PM Andrew Morton <akpm@linux-foundation.org> wrote: > > On Thu, 13 Apr 2023 02:27:19 +0800 kernel test robot <lkp@intel.com> wrote: > > > Hi Alexander, > > > > kernel test robot noticed the following build errors: > > > > [auto build test ERROR on akpm-mm/mm-everything] > > > > >> include/linux/kmsan.h:291:1: error: non-void function does not return a value [-Werror,-Wreturn-type] > > Thanks, I'll do this: Thanks! I sent an updated version of the patch series, which includes your fix as well as a couple more improvements (__must_check annotations in particular)
diff --git a/include/linux/kmsan.h b/include/linux/kmsan.h index e38ae3c346184..a0769d4aad1c8 100644 --- a/include/linux/kmsan.h +++ b/include/linux/kmsan.h @@ -134,11 +134,12 @@ void kmsan_kfree_large(const void *ptr); * @page_shift: page_shift passed to vmap_range_noflush(). * * KMSAN maps shadow and origin pages of @pages into contiguous ranges in - * vmalloc metadata address range. + * vmalloc metadata address range. Returns 0 on success, callers must check + * for non-zero return value. */ -void kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end, - pgprot_t prot, struct page **pages, - unsigned int page_shift); +int kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end, + pgprot_t prot, struct page **pages, + unsigned int page_shift); /** * kmsan_vunmap_kernel_range_noflush() - Notify KMSAN about a vunmap. @@ -281,11 +282,11 @@ static inline void kmsan_kfree_large(const void *ptr) { } -static inline void kmsan_vmap_pages_range_noflush(unsigned long start, - unsigned long end, - pgprot_t prot, - struct page **pages, - unsigned int page_shift) +static inline int kmsan_vmap_pages_range_noflush(unsigned long start, + unsigned long end, + pgprot_t prot, + struct page **pages, + unsigned int page_shift) { } diff --git a/mm/kmsan/shadow.c b/mm/kmsan/shadow.c index a787c04e9583c..b8bb95eea5e3d 100644 --- a/mm/kmsan/shadow.c +++ b/mm/kmsan/shadow.c @@ -216,27 +216,29 @@ void kmsan_free_page(struct page *page, unsigned int order) kmsan_leave_runtime(); } -void kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end, - pgprot_t prot, struct page **pages, - unsigned int page_shift) +int kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end, + pgprot_t prot, struct page **pages, + unsigned int page_shift) { unsigned long shadow_start, origin_start, shadow_end, origin_end; struct page **s_pages, **o_pages; - int nr, mapped; + int nr, mapped, err = 0; if (!kmsan_enabled) - return; + return 0; shadow_start = vmalloc_meta((void *)start, KMSAN_META_SHADOW); shadow_end = vmalloc_meta((void *)end, KMSAN_META_SHADOW); if (!shadow_start) - return; + return 0; nr = (end - start) / PAGE_SIZE; s_pages = kcalloc(nr, sizeof(*s_pages), GFP_KERNEL); o_pages = kcalloc(nr, sizeof(*o_pages), GFP_KERNEL); - if (!s_pages || !o_pages) + if (!s_pages || !o_pages) { + err = -ENOMEM; goto ret; + } for (int i = 0; i < nr; i++) { s_pages[i] = shadow_page_for(pages[i]); o_pages[i] = origin_page_for(pages[i]); @@ -249,10 +251,16 @@ void kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end, kmsan_enter_runtime(); mapped = __vmap_pages_range_noflush(shadow_start, shadow_end, prot, s_pages, page_shift); - KMSAN_WARN_ON(mapped); + if (mapped) { + err = mapped; + goto ret; + } mapped = __vmap_pages_range_noflush(origin_start, origin_end, prot, o_pages, page_shift); - KMSAN_WARN_ON(mapped); + if (mapped) { + err = mapped; + goto ret; + } kmsan_leave_runtime(); flush_tlb_kernel_range(shadow_start, shadow_end); flush_tlb_kernel_range(origin_start, origin_end); @@ -262,6 +270,7 @@ void kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end, ret: kfree(s_pages); kfree(o_pages); + return err; } /* Allocate metadata for pages allocated at boot time. */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a50072066221a..1355d95cce1ca 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -605,7 +605,11 @@ int __vmap_pages_range_noflush(unsigned long addr, unsigned long end, int vmap_pages_range_noflush(unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, unsigned int page_shift) { - kmsan_vmap_pages_range_noflush(addr, end, prot, pages, page_shift); + int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages, + page_shift); + + if (ret) + return ret; return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift); }
As reported by Dipanjan Das, when KMSAN is used together with kernel fault injection (or, generally, even without the latter), calls to kcalloc() or __vmap_pages_range_noflush() may fail, leaving the metadata mappings for the virtual mapping in an inconsistent state. When these metadata mappings are accessed later, the kernel crashes. To address the problem, we return a non-zero error code from kmsan_vmap_pages_range_noflush() in the case of any allocation/mapping failure inside it, and make vmap_pages_range_noflush() return an error if KMSAN fails to allocate the metadata. This patch also removes KMSAN_WARN_ON() from vmap_pages_range_noflush(), as these allocation failures are not fatal anymore. Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com> Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/ Fixes: b073d7f8aee4 ("mm: kmsan: maintain KMSAN metadata for page operations") Signed-off-by: Alexander Potapenko <glider@google.com> --- include/linux/kmsan.h | 19 ++++++++++--------- mm/kmsan/shadow.c | 27 ++++++++++++++++++--------- mm/vmalloc.c | 6 +++++- 3 files changed, 33 insertions(+), 19 deletions(-)