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authorAnshuman Khandual <anshuman.khandual@arm.com>2024-04-15 12:40:03 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2024-04-15 19:44:38 +0300
commit015a12a4a6708d9cadcaea8334e270747923394c (patch)
tree8c7928bc1f67039a86a48ef1fc81c0de78e3af57
parente3ba51ab24fddef79fc212f9840de54db8fd1685 (diff)
downloadlinux-015a12a4a6708d9cadcaea8334e270747923394c.tar.xz
arm64/hugetlb: Fix page table walk in huge_pte_alloc()
Currently normal HugeTLB fault ends up crashing the kernel, as p4dp derived from p4d_offset() is an invalid address when PGTABLE_LEVEL = 5. A p4d level entry needs to be allocated when not available while walking the page table during HugeTLB faults. Let's call p4d_alloc() to allocate such entries when required instead of current p4d_offset(). Unable to handle kernel paging request at virtual address ffffffff80000000 Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 52-bit VAs, pgdp=0000000081da9000 [ffffffff80000000] pgd=1000000082cec003, p4d=0000000082c32003, pud=0000000000000000 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 108 Comm: high_addr_hugep Not tainted 6.9.0-rc4 #48 Hardware name: Foundation-v8A (DT) pstate: 01402005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : huge_pte_alloc+0xd4/0x334 lr : hugetlb_fault+0x1b8/0xc68 sp : ffff8000833bbc20 x29: ffff8000833bbc20 x28: fff000080080cb58 x27: ffff800082a7cc58 x26: 0000000000000000 x25: fff0000800378e40 x24: fff00008008d6c60 x23: 00000000de9dbf07 x22: fff0000800378e40 x21: 0004000000000000 x20: 0004000000000000 x19: ffffffff80000000 x18: 1ffe00010011d7a1 x17: 0000000000000001 x16: ffffffffffffffff x15: 0000000000000001 x14: 0000000000000000 x13: ffff8000816120d0 x12: ffffffffffffffff x11: 0000000000000000 x10: fff00008008ebd0c x9 : 0004000000000000 x8 : 0000000000001255 x7 : fff00008003e2000 x6 : 00000000061d54b0 x5 : 0000000000001000 x4 : ffffffff80000000 x3 : 0000000000200000 x2 : 0000000000000004 x1 : 0000000080000000 x0 : 0000000000000000 Call trace: huge_pte_alloc+0xd4/0x334 hugetlb_fault+0x1b8/0xc68 handle_mm_fault+0x260/0x29c do_page_fault+0xfc/0x47c do_translation_fault+0x68/0x74 do_mem_abort+0x44/0x94 el0_da+0x2c/0x9c el0t_64_sync_handler+0x70/0xc4 el0t_64_sync+0x190/0x194 Code: aa000084 cb010084 b24c2c84 8b130c93 (f9400260) ---[ end trace 0000000000000000 ]--- Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Fixes: a6bbf5d4d9d1 ("arm64: mm: Add definitions to support 5 levels of paging") Reported-by: Dev Jain <dev.jain@arm.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://lore.kernel.org/r/20240415094003.1812018-1-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/mm/hugetlbpage.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 0f0e10bb0a95..b872b003a55f 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -276,7 +276,10 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
pte_t *ptep = NULL;
pgdp = pgd_offset(mm, addr);
- p4dp = p4d_offset(pgdp, addr);
+ p4dp = p4d_alloc(mm, pgdp, addr);
+ if (!p4dp)
+ return NULL;
+
pudp = pud_alloc(mm, p4dp, addr);
if (!pudp)
return NULL;