* git name-rev segfault
@ 2019-07-29 14:19 Tamas Papp
2019-07-29 19:50 ` Jeff King
0 siblings, 1 reply; 3+ messages in thread
From: Tamas Papp @ 2019-07-29 14:19 UTC (permalink / raw)
To: git
hi All,
We ran into a segfault with all version of command line git.
We are able to reproduce this issue by this way:
Generate 100k file into a repository:
#!/bin/bash
rm -rf .git test.file
git init
git config user.email a@b
git config user.name c
time for i in {1..100000}
do
[ $((i % 2)) -eq 1 ] && echo $i>test.file || echo 0 >test.file
git add test.file
git commit -m "$i committed"
done
Run git on it:
$ git name-rev a20f6989b75fa63ec6259a988e38714e1f5328a0
Could you coment on it?
Thank you,
tamas
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: git name-rev segfault
2019-07-29 14:19 git name-rev segfault Tamas Papp
@ 2019-07-29 19:50 ` Jeff King
2019-07-29 20:00 ` Tamas Papp
0 siblings, 1 reply; 3+ messages in thread
From: Jeff King @ 2019-07-29 19:50 UTC (permalink / raw)
To: Tamas Papp; +Cc: git
On Mon, Jul 29, 2019 at 04:19:47PM +0200, Tamas Papp wrote:
> Generate 100k file into a repository:
>
> #!/bin/bash
>
> rm -rf .git test.file
> git init
> git config user.email a@b
> git config user.name c
>
> time for i in {1..100000}
> do
> [ $((i % 2)) -eq 1 ] && echo $i>test.file || echo 0 >test.file
> git add test.file
>
> git commit -m "$i committed"
>
> done
I lost patience kicking off two hundred thousand processes. Try this:
for i in {1..100000}
do
echo "commit HEAD"
echo "committer c <a@b> $i +0000"
echo "data <<EOF"
echo "$i committed"
echo "EOF"
echo
done | git fast-import
which runs much faster. This doesn't change any files in each commit,
but I don't think it's necessary for what you're showing (name-rev
wouldn't ever look at the trees).
> Run git on it:
>
> $ git name-rev a20f6989b75fa63ec6259a988e38714e1f5328a0
Anybody who runs your script will get a different sha1 because of the
change in timestamps. I guess this is HEAD, though. I also needed to
have an actual tag to find. So:
git tag old-tag HEAD~99999
git name-rev HEAD
segfaults for me.
> Could you coment on it?
This is a known issue. The algorithm used by name-rev is recursive, and
you can run out of stack space in some deep cases. There's more
discussion this thread:
https://public-inbox.org/git/6a4cbbee-ffc6-739b-d649-079ba01439ca@grubix.eu/
including some patches that document the problem with an expected
failure in our test suite. Nobody has actually rewritten the C code yet,
though.
-Peff
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: git name-rev segfault
2019-07-29 19:50 ` Jeff King
@ 2019-07-29 20:00 ` Tamas Papp
0 siblings, 0 replies; 3+ messages in thread
From: Tamas Papp @ 2019-07-29 20:00 UTC (permalink / raw)
To: Jeff King; +Cc: git
Thanks for letting me know and for the corrections too.
Cheers,
tamas
On 7/29/19 9:50 PM, Jeff King wrote:
> On Mon, Jul 29, 2019 at 04:19:47PM +0200, Tamas Papp wrote:
>
>> Generate 100k file into a repository:
>>
>> #!/bin/bash
>>
>> rm -rf .git test.file
>> git init
>> git config user.email a@b
>> git config user.name c
>>
>> time for i in {1..100000}
>> do
>> [ $((i % 2)) -eq 1 ] && echo $i>test.file || echo 0 >test.file
>> git add test.file
>>
>> git commit -m "$i committed"
>>
>> done
> I lost patience kicking off two hundred thousand processes. Try this:
>
> for i in {1..100000}
> do
> echo "commit HEAD"
> echo "committer c <a@b> $i +0000"
> echo "data <<EOF"
> echo "$i committed"
> echo "EOF"
> echo
> done | git fast-import
>
> which runs much faster. This doesn't change any files in each commit,
> but I don't think it's necessary for what you're showing (name-rev
> wouldn't ever look at the trees).
>
>> Run git on it:
>>
>> $ git name-rev a20f6989b75fa63ec6259a988e38714e1f5328a0
> Anybody who runs your script will get a different sha1 because of the
> change in timestamps. I guess this is HEAD, though. I also needed to
> have an actual tag to find. So:
>
> git tag old-tag HEAD~99999
> git name-rev HEAD
>
> segfaults for me.
>
>> Could you coment on it?
> This is a known issue. The algorithm used by name-rev is recursive, and
> you can run out of stack space in some deep cases. There's more
> discussion this thread:
>
> https://public-inbox.org/git/6a4cbbee-ffc6-739b-d649-079ba01439ca@grubix.eu/
>
> including some patches that document the problem with an expected
> failure in our test suite. Nobody has actually rewritten the C code yet,
> though.
>
> -Peff
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-07-29 20:00 UTC | newest]
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2019-07-29 14:19 git name-rev segfault Tamas Papp
2019-07-29 19:50 ` Jeff King
2019-07-29 20:00 ` Tamas Papp
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