kernel test robot <l...@intel.com> writes:
> Greeting,
>
> FYI, we noticed the following commit (built with gcc-9):
>
> commit: c50eb1ed654b59efad96884cc26895a0acd7a15a ("mm/debug_vm_pgtable/locks:
> move non page table modifying test together")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>
>
> in testcase: boot
>
> on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 8G
>
> caused below changes (please refer to attached dmesg/kmsg for entire
> log/backtrace):
>
>
> +----------------------------------------------------------------------+------------+------------+
> | |
> 5c65ca35e5 | c50eb1ed65 |
> +----------------------------------------------------------------------+------------+------------+
> | boot_successes | 18
> | 0 |
> | boot_failures | 0
> | 10 |
> | BUG:sleeping_function_called_from_invalid_context_at_mm/page_alloc.c | 0
> | 10 |
> +----------------------------------------------------------------------+------------+------------+
>
>
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <l...@intel.com>
>
How about this?
>From a654324a2d09c61b9fb271b550f543ef7b09adc1 Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com>
Date: Sun, 13 Sep 2020 13:34:26 +0530
Subject: [PATCH] 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 <l...@intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
mm/debug_vm_pgtable.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index d12bde82ae95..109fdf9953ad 100644
--- a/mm/debug_vm_pgtable.c
+++ b/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);
--
2.26.2
