From: Christophe Leroy Date: Sat, 12 Dec 2020 13:41:25 +0000 (+0000) Subject: powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2198d4934ee8b81341a84c9ec8bb25b4b0d02522;p=linux.git powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range() Commit 7bfe54b5f165 ("powerpc/mm: Refactor the floor/ceiling check in hugetlb range freeing functions") inadvertely removed the mask applied to start parameter in those two functions, leading to the following crash on power9. LTP: starting hugemmap05_1 (hugemmap05 -m) ------------[ cut here ]------------ kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:387! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=256 NUMA PowerNV ... CPU: 99 PID: 308 Comm: ksoftirqd/99 Tainted: G O 5.10.0-rc7-next-20201211 #1 NIP: c00000000005dbec LR: c0000000003352f4 CTR: 0000000000000000 REGS: c00020000bb6f830 TRAP: 0700 Tainted: G O (5.10.0-rc7-next-20201211) MSR: 900000000282b033 CR: 24002284 XER: 20040000 GPR00: c0000000003352f4 c00020000bb6fad0 c000000007f70b00 c0002000385b3ff0 GPR04: 0000000000000000 0000000000000003 c00020000bb6f8b4 0000000000000001 GPR08: 0000000000000001 0000000000000009 0000000000000008 0000000000000002 GPR12: 0000000024002488 c000201fff649c00 c000000007f2a20c 0000000000000000 GPR16: 0000000000000007 0000000000000000 c000000000194d10 c000000000194d10 GPR24: 0000000000000014 0000000000000015 c000201cc6e72398 c000000007fac4b4 GPR28: c000000007f2bf80 c000000007fac2f8 0000000000000008 c000200033870000 NIP [c00000000005dbec] __tlb_remove_table+0x1dc/0x1e0 pgtable_free at arch/powerpc/mm/book3s64/pgtable.c:387 (inlined by) __tlb_remove_table at arch/powerpc/mm/book3s64/pgtable.c:405 LR [c0000000003352f4] tlb_remove_table_rcu+0x54/0xa0 Call Trace: __tlb_remove_table+0x13c/0x1e0 (unreliable) tlb_remove_table_rcu+0x54/0xa0 __tlb_remove_table_free at mm/mmu_gather.c:101 (inlined by) tlb_remove_table_rcu at mm/mmu_gather.c:156 rcu_core+0x35c/0xbb0 rcu_do_batch at kernel/rcu/tree.c:2502 (inlined by) rcu_core at kernel/rcu/tree.c:2737 __do_softirq+0x480/0x704 run_ksoftirqd+0x74/0xd0 run_ksoftirqd at kernel/softirq.c:651 (inlined by) run_ksoftirqd at kernel/softirq.c:642 smpboot_thread_fn+0x278/0x320 kthread+0x1c4/0x1d0 ret_from_kernel_thread+0x5c/0x80 Properly apply the masks before calling pmd_free_tlb() and pud_free_tlb() respectively. Fixes: 7bfe54b5f165 ("powerpc/mm: Refactor the floor/ceiling check in hugetlb range freeing functions") Reported-by: Qian Cai Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/56feccd7b6fcd98e353361a233fa7bb8e67c3164.1607780469.git.christophe.leroy@csgroup.eu --- diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index f8d8a4988e151..8b3cc4d688e8b 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -396,9 +396,9 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, if (range_is_outside_limits(start, end, floor, ceiling, PUD_MASK)) return; - pmd = pmd_offset(pud, start); + pmd = pmd_offset(pud, start & PUD_MASK); pud_clear(pud); - pmd_free_tlb(tlb, pmd, start); + pmd_free_tlb(tlb, pmd, start & PUD_MASK); mm_dec_nr_pmds(tlb->mm); } @@ -439,9 +439,9 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d, if (range_is_outside_limits(start, end, floor, ceiling, PGDIR_MASK)) return; - pud = pud_offset(p4d, start); + pud = pud_offset(p4d, start & PGDIR_MASK); p4d_clear(p4d); - pud_free_tlb(tlb, pud, start); + pud_free_tlb(tlb, pud, start & PGDIR_MASK); mm_dec_nr_puds(tlb->mm); }