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Subject[PATCH 4.14 31/89] x86/kasan: Panic if there is not enough memory to boot
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrey Ryabinin <aryabinin@virtuozzo.com>

commit 0d39e2669d7b0fefd2d8f9e7868ae669b364d9ba upstream.

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>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
Cc: Alexander Potapenko <glider@google.com>
Cc: lkp@01.org
Link: https://lkml.kernel.org/r/20180110153602.18919-1-aryabinin@virtuozzo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/mm/kasan_init_64.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)

--- 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_

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(pm
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(pm
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(pu
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(p4
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(pg
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);
}


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