On Wed, Jan 10, 2018 at 4:36 PM, Andrey Ryabinin
<aryabi...@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...@intel.com>
> Signed-off-by: Andrey Ryabinin <aryabi...@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 <dvyu...@google.com>
Thanks!
