Hello git users,
I'm running into git crashing with an stack overflow and hope to hear
your views on this.
I have a from SVN converted repository (using Subgit). If I execute
"git name-rev 92f054ba5c71b8e689aed529ff31370984089b64" on this bare
repository, git crashes with a stack overflow.
One property of the git conversion process is that at every commit a
note is attached which lists the SVN version number. This repository
has over 50000 commits.
In addition, refs exist at refs/svn/map which also contains many
entries. It appears the name-rev looks at the notes and other refs as
well.
The backtrace of the stack overflow is this:
[repeats many times]
#12976 0x000000000046d178 in name_rev (commit=0x37241b0,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101, generation=3,
distance=3, from_tag=0, deref=0) at builtin/name-rev.c:139
#12977 0x000000000046d178 in name_rev (commit=0x3724160,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101, generation=2,
distance=2, from_tag=0, deref=0) at builtin/name-rev.c:139
#12978 0x000000000046d178 in name_rev (commit=0x3724110,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101, generation=1,
distance=1, from_tag=0, deref=0) at builtin/name-rev.c:139
#12979 0x000000000046d178 in name_rev (commit=0x37240c0,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101, generation=0,
distance=0, from_tag=0, deref=0) at builtin/name-rev.c:139
#12980 0x000000000046d69d in name_ref (path=0x37232e5 "notes/commits",
oid=0x37c6030, flags=66, cb_data=0x155ef20) at builtin/name-rev.c:277
#12981 0x00000000005c6645 in do_for_each_ref_helper (r=0x7acee0 <the_repo>,
refname=0x37232e0 "refs/notes/commits", oid=0x37c6030, flags=66,
cb_data=0x155ede0) at refs.c:1552
#12982 0x00000000005cfcd1 in do_for_each_repo_ref_iterator (
r=0x7acee0 <the_repo>, iter=0x37c6190,
fn=0x5c65ff <do_for_each_ref_helper>, cb_data=0x155ede0)
at refs/iterator.c:418
#12983 0x00000000005c66de in do_for_each_ref (refs=0x3716aa8,
prefix=0x71d34f <__ac_HASH_UPPER+271> "", fn=0x46d3ff <name_ref>, trim=0,
flags=0, cb_data=0x155ef20) at refs.c:1566
#12984 0x00000000005c673f in refs_for_each_ref (refs=0x3716aa8,
fn=0x46d3ff <name_ref>, cb_data=0x155ef20) at refs.c:1572
#12985 0x00000000005c677a in for_each_ref (fn=0x46d3ff <name_ref>,
cb_data=0x155ef20) at refs.c:1577
#12986 0x000000000046e2c1 in cmd_name_rev (argc=0, argv=0x37106b8, prefix=0x0)
at builtin/name-rev.c:495
#12987 0x000000000040305c in run_builtin (p=0x6b56e8 <commands+1704>, argc=2,
argv=0x37106b0) at git.c:444
#12988 0x0000000000403446 in handle_builtin (argc=2, argv=0x37106b0)
at git.c:673
#12989 0x00000000004036fc in run_argv (argcp=0x155fdb0, argv=0x155fd58)
at git.c:740
#12990 0x0000000000403b62 in cmd_main (argc=2, argv=0x37106b0) at git.c:871
#12991 0x00000000004c8647 in main (argc=3, argv=0x37106a8) at common-main.c:52
If I trace it back to the source we get this:
(gdb)
#16 0x000000000046d178 in name_rev (commit=0x3b948d30,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101,
generation=12963, distance=12963, from_tag=0, deref=0)
at builtin/name-rev.c:139
139 name_rev(parents->item, tip_name, taggerdate,
(gdb)
#17 0x000000000046d178 in name_rev (commit=0x3b948ce0,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101,
generation=12962, distance=12962, from_tag=0, deref=0)
at builtin/name-rev.c:139
139 name_rev(parents->item, tip_name, taggerdate,
(gdb)
#18 0x000000000046d178 in name_rev (commit=0x3b948c90,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101,
generation=12961, distance=12961, from_tag=0, deref=0)
at builtin/name-rev.c:139
139 name_rev(parents->item, tip_name, taggerdate,
(gdb)
#19 0x000000000046d178 in name_rev (commit=0x3b948c40,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101,
generation=12960, distance=12960, from_tag=0, deref=0)
at builtin/name-rev.c:139
139 name_rev(parents->item, tip_name, taggerdate,
(gdb)
#20 0x000000000046d178 in name_rev (commit=0x3b948bf0,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101,
generation=12959, distance=12959, from_tag=0, deref=0)
at builtin/name-rev.c:139
139 name_rev(parents->item, tip_name, taggerdate,
(gdb)
#21 0x000000000046d178 in name_rev (commit=0x3b948ba0,
tip_name=0x37ccb70 "notes/commits", taggerdate=1572995101,
generation=12958, distance=12958, from_tag=0, deref=0)
at builtin/name-rev.c:139
139
Essentially too much, but not endless recursion, causing a stack overflow.
The destructive workaround at the moment is to delete the refs, then
run an aggressive gc:
git update-ref -d refs/notes/commits
git update-ref -d refs/svn/map
git gc --prune=all --aggressive
I was redirected here by the git-for-windows team (issue link if
you're interested:
https://github.com/git-for-windows/git/issues/2393), so I'm going to
repeat what was said there:
> But yes, the problem seems to be the many, many notes. Which points to a deeper issue: name_rev should not even look at anything byt refs/heads/*, refs/remotes/* and refs/tags/. Certainly it should exclude refs/notes/*...
> This, however, is not Windows-specific. Maybe I can ask you to report this issue to the Git mailing list (git@xxxxxxxxxxxxxxx, please suppress all HTML lest the mail will be bounced)?
I hope to hear your view on this. Is this an (confirmed) issue with
git? Are there beside the workaround I mentioned, any other
workarounds?
Groeten, Kind regards,
Sebastiaan Dammann
