Messages in this thread | | | From | Dmitry Vyukov <> | Date | Wed, 10 Jan 2018 16:40:38 +0100 | Subject | Re: [PATCH] x86/kasan: panic if there is not enough memory to boot. |
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On Wed, Jan 10, 2018 at 4:36 PM, Andrey Ryabinin <aryabinin@virtuozzo.com> wrote: > Currently KASAN doesn't panic in case it don't have enough memory > to boot. Instead, it crashes in some random place: > > kernel BUG at arch/x86/mm/physaddr.c:27! > > RIP: 0010:__phys_addr+0x268/0x276 > Call Trace: > kasan_populate_shadow+0x3f2/0x497 > kasan_init+0x12e/0x2b2 > setup_arch+0x2825/0x2a2c > start_kernel+0xc8/0x15f4 > x86_64_start_reservations+0x2a/0x2c > x86_64_start_kernel+0x72/0x75 > secondary_startup_64+0xa5/0xb0 > > Use memblock_virt_alloc_try_nid() for allocations without failure > fallback. It will panic with an out of memory message. > > Reported-by: kernel test robot <xiaolong.ye@intel.com> > Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> > --- > arch/x86/mm/kasan_init_64.c | 24 ++++++++++++++---------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c > index 47388f0c0e59..af6f2f9c6a26 100644 > --- a/arch/x86/mm/kasan_init_64.c > +++ b/arch/x86/mm/kasan_init_64.c > @@ -21,10 +21,14 @@ extern struct range pfn_mapped[E820_MAX_ENTRIES]; > > static p4d_t tmp_p4d_table[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE); > > -static __init void *early_alloc(size_t size, int nid) > +static __init void *early_alloc(size_t size, int nid, bool panic) > { > - return memblock_virt_alloc_try_nid_nopanic(size, size, > - __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); > + if (panic) > + return memblock_virt_alloc_try_nid(size, size, > + __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); > + else > + return memblock_virt_alloc_try_nid_nopanic(size, size, > + __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); > } > > static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr, > @@ -38,14 +42,14 @@ static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr, > if (boot_cpu_has(X86_FEATURE_PSE) && > ((end - addr) == PMD_SIZE) && > IS_ALIGNED(addr, PMD_SIZE)) { > - p = early_alloc(PMD_SIZE, nid); > + p = early_alloc(PMD_SIZE, nid, false); > if (p && pmd_set_huge(pmd, __pa(p), PAGE_KERNEL)) > return; > else if (p) > memblock_free(__pa(p), PMD_SIZE); > } > > - p = early_alloc(PAGE_SIZE, nid); > + p = early_alloc(PAGE_SIZE, nid, true); > pmd_populate_kernel(&init_mm, pmd, p); > } > > @@ -57,7 +61,7 @@ static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr, > if (!pte_none(*pte)) > continue; > > - p = early_alloc(PAGE_SIZE, nid); > + p = early_alloc(PAGE_SIZE, nid, true); > entry = pfn_pte(PFN_DOWN(__pa(p)), PAGE_KERNEL); > set_pte_at(&init_mm, addr, pte, entry); > } while (pte++, addr += PAGE_SIZE, addr != end); > @@ -75,14 +79,14 @@ static void __init kasan_populate_pud(pud_t *pud, unsigned long addr, > if (boot_cpu_has(X86_FEATURE_GBPAGES) && > ((end - addr) == PUD_SIZE) && > IS_ALIGNED(addr, PUD_SIZE)) { > - p = early_alloc(PUD_SIZE, nid); > + p = early_alloc(PUD_SIZE, nid, false); > if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL)) > return; > else if (p) > memblock_free(__pa(p), PUD_SIZE); > } > > - p = early_alloc(PAGE_SIZE, nid); > + p = early_alloc(PAGE_SIZE, nid, true); > pud_populate(&init_mm, pud, p); > } > > @@ -101,7 +105,7 @@ static void __init kasan_populate_p4d(p4d_t *p4d, unsigned long addr, > unsigned long next; > > if (p4d_none(*p4d)) { > - void *p = early_alloc(PAGE_SIZE, nid); > + void *p = early_alloc(PAGE_SIZE, nid, true); > > p4d_populate(&init_mm, p4d, p); > } > @@ -122,7 +126,7 @@ static void __init kasan_populate_pgd(pgd_t *pgd, unsigned long addr, > unsigned long next; > > if (pgd_none(*pgd)) { > - p = early_alloc(PAGE_SIZE, nid); > + p = early_alloc(PAGE_SIZE, nid, true); > pgd_populate(&init_mm, pgd, p); > }
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Thanks!
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