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author | Al Viro <viro@zeniv.linux.org.uk> | 2008-05-08 21:19:42 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-05-16 17:22:46 -0400 |
commit | adbecb128cd2cc5d14b0ebef6d020ced0efd0ec6 (patch) | |
tree | ba0f7c202e364002eedc999526ac07262f21dae4 /virt/kvm | |
parent | afbec7fff4928c273a1f1bb14dfdfdf62688a193 (diff) |
[PATCH] dup_fd() part 4 - race fix
Parent _can_ be a clone task, contrary to the comment. Moreover,
more files could be opened while we allocate a copy, in which case
we end up copying only part into new descriptor table. Since what
we get _is_ affected by all changes in the old range, we can get
rather weird effects - e.g.
dup2(0, 1024); close(0);
in parallel with fork() resulting in child that sees the effect of
close(), but not that of dup2() done just before that close().
What we need is to recalculate the open_count after having reacquired
->file_lock and if external fdtable we'd just allocated is too small for
it, free the sucker and redo allocation.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'virt/kvm')
0 files changed, 0 insertions, 0 deletions