The patch titled
Subject: mm/debug_vm_pgtable: Avoid doing memory allocation with pgtable_t mapped
has been added to the -mm tree. Its filename is
mm-debug_vm_pgtable-avoid-doing-memory-allocation-with-pgtable_t-mapped.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-debug_vm_pgtable-avoid-doing-memory-allocation-with-pgtable_t-mapped.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-debug_vm_pgtable-avoid-doing-memory-allocation-with-pgtable_t-mapped.patch
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------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Subject: mm/debug_vm_pgtable: Avoid doing memory allocation with pgtable_t mapped
With highmem, pte_alloc_map() keep the level4 page table mapped using
kmap_atomic(). Avoid doing new memory allocation with page table mapped
like above.
[ 9.409233] BUG: sleeping function called from invalid context at mm/page_alloc.c:4822
[ 9.410557] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper
[ 9.411932] no locks held by swapper/1.
[ 9.412595] CPU: 0 PID: 1 Comm: swapper Not tainted 5.9.0-rc3-00323-gc50eb1ed654b5 #2
[ 9.413824] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[ 9.415207] Call Trace:
[ 9.415651] ? ___might_sleep.cold+0xa7/0xcc
[ 9.416367] ? __alloc_pages_nodemask+0x14c/0x5b0
[ 9.417055] ? swap_migration_tests+0x50/0x293
[ 9.417704] ? debug_vm_pgtable+0x4bc/0x708
[ 9.418287] ? swap_migration_tests+0x293/0x293
[ 9.418911] ? do_one_initcall+0x82/0x3cb
[ 9.419465] ? parse_args+0x1bd/0x280
[ 9.419983] ? rcu_read_lock_sched_held+0x36/0x60
[ 9.420673] ? trace_initcall_level+0x1f/0xf3
[ 9.421279] ? trace_initcall_level+0xbd/0xf3
[ 9.421881] ? do_basic_setup+0x9d/0xdd
[ 9.422410] ? do_basic_setup+0xc3/0xdd
[ 9.422938] ? kernel_init_freeable+0x72/0xa3
[ 9.423539] ? rest_init+0x134/0x134
[ 9.424055] ? kernel_init+0x5/0x12c
[ 9.424574] ? ret_from_fork+0x19/0x30
Link: https://lkml.kernel.org/r/87wo0yw0gk.fsf@xxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/debug_vm_pgtable.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-avoid-doing-memory-allocation-with-pgtable_t-mapped
+++ a/mm/debug_vm_pgtable.c
@@ -994,7 +994,10 @@ static int __init debug_vm_pgtable(void)
p4dp = p4d_alloc(mm, pgdp, vaddr);
pudp = pud_alloc(mm, p4dp, vaddr);
pmdp = pmd_alloc(mm, pudp, vaddr);
- ptep = pte_alloc_map(mm, pmdp, vaddr);
+ /*
+ * Allocate pgtable_t
+ */
+ pte_alloc(mm, pmdp);
/*
* Save all the page table page addresses as the page table
@@ -1048,8 +1051,7 @@ static int __init debug_vm_pgtable(void)
* proper page table lock.
*/
- ptl = pte_lockptr(mm, pmdp);
- spin_lock(ptl);
+ ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl);
pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot);
pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
pte_unmap_unlock(ptep, ptl);
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxx are
powerpc-mm-add-debug_vm-warn-for-pmd_clear.patch
powerpc-mm-move-setting-pte-specific-flags-to-pfn_pte.patch
mm-debug_vm_pgtable-ppc64-avoid-setting-top-bits-in-radom-value.patch
mm-debug_vm_pgtables-hugevmap-use-the-arch-helper-to-identify-huge-vmap-support.patch
mm-debug_vm_pgtable-savedwrite-enable-savedwrite-test-with-config_numa_balancing.patch
mm-debug_vm_pgtable-thp-mark-the-pte-entry-huge-before-using-set_pmd-pud_at.patch
mm-debug_vm_pgtable-set_pte-pmd-pud-dont-use-set__at-to-update-an-existing-pte-entry.patch
mm-debug_vm_pgtable-locks-move-non-page-table-modifying-test-together.patch
mm-debug_vm_pgtable-locks-take-correct-page-table-lock.patch
mm-debug_vm_pgtable-thp-use-page-table-depost-withdraw-with-thp.patch
mm-debug_vm_pgtable-pmd_clear-dont-use-pmd-pud_clear-on-pte-entries.patch
mm-debug_vm_pgtable-hugetlb-disable-hugetlb-test-on-ppc64.patch
mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch
mm-debug_vm_pgtable-avoid-doing-memory-allocation-with-pgtable_t-mapped.patch
