From: Aneesh Kumar K.V Date: Fri, 16 Oct 2020 03:05:10 +0000 (-0700) Subject: mm/debug_vm_pgtable: avoid doing memory allocation with pgtable_t mapped. X-Git-Tag: microblaze-v5.11~109^2~141 X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=f14312e1ed1e40dfed38bb70eb9a71d97a6b60f4 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 Reported-by: kernel test robot Signed-off-by: Aneesh Kumar K.V Signed-off-by: Andrew Morton Link: https://lkml.kernel.org/r/20200913110327.645310-1-aneesh.kumar@linux.ibm.com Signed-off-by: Linus Torvalds --- diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 9a0a42a4f08d..c05d9dcf7891 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -943,7 +943,13 @@ 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 + */ + if (pte_alloc(mm, pmdp)) { + pr_err("pgtable allocation failed\n"); + return 1; + } /* * Save all the page table page addresses as the page table @@ -997,8 +1003,7 @@ 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);