diff options
author | Hugh Dickins <hugh@veritas.com> | 2007-10-04 16:56:06 +0100 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-04 10:13:09 -0700 |
commit | 16abfa086096895d438b19198e408ee96da7b508 (patch) | |
tree | 1d82091f35f069d7b2a7636b5f488987671bdade /security/Kconfig | |
parent | 804b3f9a16e446cb023417faec58b6506c834052 (diff) | |
download | linux-16abfa086096895d438b19198e408ee96da7b508.tar.gz linux-16abfa086096895d438b19198e408ee96da7b508.tar.bz2 linux-16abfa086096895d438b19198e408ee96da7b508.zip |
Fix sys_remap_file_pages BUG at highmem.c:15!
Gurudas Pai reports kernel BUG at arch/i386/mm/highmem.c:15! below
sys_remap_file_pages, while running Oracle database test on x86 in 6GB
RAM: kunmap thinks we're in_interrupt because the preempt count has
wrapped.
That's because __do_fault expected to unmap page_table, but one of its
two callers do_nonlinear_fault already unmapped it: let do_linear_fault
unmap it first too, and then there's no need to pass the page_table arg
down.
Why have we been so slow to notice this? Probably through forgetting
that the mapping_cap_account_dirty test means that sys_remap_file_pages
nowadays only goes the full nonlinear vma route on a few memory-backed
filesystems like ramfs, tmpfs and hugetlbfs.
[ It also depends on CONFIG_HIGHPTE, so it becomes even harder to
trigger in practice. Many who have need of large memory have probably
migrated to x86-64..
Problem introduced by commit d0217ac04ca6591841e5665f518e38064f4e65bd
("mm: fault feedback #1") -- Linus ]
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: gurudas pai <gurudas.pai@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security/Kconfig')
0 files changed, 0 insertions, 0 deletions