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Chuck Ebbert |
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From: Roland McGrath <roland@redhat.com>
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Chuck Ebbert |
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Date: Wed, 8 Sep 2010 02:36:28 +0000 (-0700)
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Chuck Ebbert |
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Subject: execve: improve interactivity with large arguments
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Chuck Ebbert |
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X-Git-Tag: v2.6.36-rc4~13
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Chuck Ebbert |
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X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=7993bc1f4663c0db67bb8f0d98e6678145b387cd
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Chuck Ebbert |
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Chuck Ebbert |
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execve: improve interactivity with large arguments
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Chuck Ebbert |
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Chuck Ebbert |
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This adds a preemption point during the copying of the argument and
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Chuck Ebbert |
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environment strings for execve, in copy_strings(). There is already
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Chuck Ebbert |
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a preemption point in the count() loop, so this doesn't add any new
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Chuck Ebbert |
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points in the abstract sense.
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Chuck Ebbert |
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Chuck Ebbert |
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When the total argument+environment strings are very large, the time
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Chuck Ebbert |
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spent copying them can be much more than a normal user time slice.
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Chuck Ebbert |
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So this change improves the interactivity of the rest of the system
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Chuck Ebbert |
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when one process is doing an execve with very large arguments.
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Chuck Ebbert |
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Chuck Ebbert |
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Signed-off-by: Roland McGrath <roland@redhat.com>
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Chuck Ebbert |
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Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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Chuck Ebbert |
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Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Chuck Ebbert |
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---
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Chuck Ebbert |
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Chuck Ebbert |
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diff --git a/fs/exec.c b/fs/exec.c
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Chuck Ebbert |
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index 1b63237..6f2d777 100644
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Chuck Ebbert |
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--- a/fs/exec.c
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Chuck Ebbert |
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+++ b/fs/exec.c
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Chuck Ebbert |
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@@ -419,6 +419,8 @@ static int copy_strings(int argc, const char __user *const __user *argv,
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Chuck Ebbert |
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while (len > 0) {
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int offset, bytes_to_copy;
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Chuck Ebbert |
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Chuck Ebbert |
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+ cond_resched();
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Chuck Ebbert |
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+
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offset = pos % PAGE_SIZE;
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Chuck Ebbert |
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if (offset == 0)
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Chuck Ebbert |
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offset = PAGE_SIZE;
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