* [BUG] Segfault on git describe
@ 2014-03-19 10:48 Sylvestre Ledru
2014-03-19 12:03 ` Sylvestre Ledru
2014-03-19 22:34 ` Dragos Foianu
0 siblings, 2 replies; 5+ messages in thread
From: Sylvestre Ledru @ 2014-03-19 10:48 UTC (permalink / raw)
To: git
[-- Attachment #1: Type: text/plain, Size: 741 bytes --]
Hello,
Trying to do some stats using the Firefox git repository
(https://github.com/mozilla/gecko-dev), I found a bug
on git describe. The following command will segfault:
git describe --contains a9ff31aebd6dbda82a3c733a72eeeaa0b0525b96
Please note that the Firefox history is a pretty long and this commit
date is 2001.
I experience this issue with the git version, and Debian packages
(1.9.0-1 and 2.0~next.20140214-2)
As attachment, the backtrace. I removed about 87250 calls to the
name_rev function. I guess that is a potential source of problem.
Full is available here:
http://people.mozilla.org/~sledru/bt-git-on-ff.txt (21 MB)
I am available to test patches if needed.
Thanks,
Sylvestre
PS: I am not registered, please cc me.
[-- Attachment #2: bt-git-on-ff-small.txt --]
[-- Type: text/plain, Size: 24883 bytes --]
#0 inflate_table (type=type@entry=CODES, lens=0x178f230, codes=codes@entry=19, table=0x178f228,
bits=bits@entry=0x178f210, work=work@entry=0x178f4b0) at inftrees.c:39
len = 0
sym = <optimized out>
min = <optimized out>
max = <optimized out>
root = <optimized out>
curr = <optimized out>
drop = <optimized out>
left = <optimized out>
used = <optimized out>
huff = <optimized out>
incr = <optimized out>
fill = <optimized out>
low = <optimized out>
mask = <optimized out>
here = <optimized out>
next = <optimized out>
base = <optimized out>
extra = <optimized out>
end = <optimized out>
count = {0, 0, 0, 0, 0, 0, 0, 0, 31046, 360, 0, 0, 62288, 376, 0, 0}
offs = {36858, 61615, 32767, 0, 0, 0, 0, 0, 127, 0, 0, 0, 65535, 65535, 0, 0}
lbase = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, 67, 83, 99, 115, 131,
163, 195, 227, 258, 0, 0}
lext = {16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21,
21, 21, 21, 16, 72, 78}
dbase = {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049,
3073, 4097, 6145, 8193, 12289, 16385, 24577, 0, 0}
dext = {16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 25, 26, 26, 27,
27, 28, 28, 29, 29, 64, 64}
#1 0x00007ffff7bce6fd in inflate (strm=0x7fffff7ff190, flush=4) at inflate.c:926
state = 0x178f1a0
next = 0x7fffb3b7e5b2 "?\305-LHU\355\070\315\271\002\006\220P\a\220\220\212\330\317\366%\265\232ĕ{\251\bOOڑ\221\177\270\341t\337w\277\024f\360hLͨu\323\006\252\254\213\232\235\363\326qh=\326\301\372M\353u\335T\352D\205G\001\364\206-\306\065\066M4&Zc\243%\215\036\071\022a0\270qƑ\v\212&9\344\002\303|\274\033\362O\352{Z\345\322\301ß\305\023\350\305\345*\264\065\302\375z\211\ny\030\222\b\377\vV\257\351\033\332屟:0\266v\306na:E\022>\303\363\324\335\330\345 _\375\222A\350\310@\361B\243Pǐ[\330}\276\277Y\240\061\302\313~\177U\r$\222\306n\245>H\302\001\374\f"...
put = <optimized out>
have = 1022863950
left = 343
hold = 59
bits = 7
in = 1022863961
out = <optimized out>
copy = <optimized out>
from = <optimized out>
here = <optimized out>
len = <optimized out>
ret = <optimized out>
hbuf = "\247U\b\003"
order = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}
#2 0x0000000000559b7d in git_inflate (strm=0x7fffff7ff190, flush=4) at zlib.c:118
status = 0
#3 0x000000000052d73d in unpack_compressed_entry (p=0x850ac0, w_curs=0x7fffff7ff8a8, curpos=50877863, size=342)
at sha1_file.c:1933
st = 0
stream = {z = {
next_in = 0x7fffb3b7e5a7 "x\234\235\216\261N\303\060\020\206w?\305-LHU\355\070\315\271\002\006\220P\a\220\220\212\330\317\366%\265\232ĕ{\251\bOOڑ\221\177\270\341t\337w\277\024f\360hLͨu\323\006\252\254\213\232\235\363\326qh=\326\301\372M\353u\335T\352D\205G\001\364\206-\306\065\066M4&Zc\243%\215\036\071\022a0\270qƑ\v\212&9\344\002\303|\274\033\362O\352{Z\345\322\301ß\305\023\350\305\345*\264\065\302\375z\211\ny\030\222\b\377\vV\257\351\033\332屟:0\266v\306na:E\022>\303\363\324\335\330\345 _\375\222A\350\310@\361B\243Pǐ[\330}\276\277Y\240\061\302\313~\177U\r"..., avail_in = 1022863961, total_in = 0, next_out = 0x178f040 "\034", avail_out = 343, total_out = 0, msg = 0x0,
state = 0x178f1a0, zalloc = 0x7ffff7bd3000 <zcalloc>, zfree = 0x7ffff7bd3010 <zcfree>, opaque = 0x0,
data_type = 0, adler = 1, reserved = 0}, avail_in = 1022863961, avail_out = 343, total_in = 0,
total_out = 0,
next_in = 0x7fffb3b7e5a7 "x\234\235\216\261N\303\060\020\206w?\305-LHU\355\070\315\271\002\006\220P\a\220\220\212\330\317\366%\265\232ĕ{\251\bOOڑ\221\177\270\341t\337w\277\024f\360hLͨu\323\006\252\254\213\232\235\363\326qh=\326\301\372M\353u\335T\352D\205G\001\364\206-\306\065\066M4&Zc\243%\215\036\071\022a0\270qƑ\v\212&9\344\002\303|\274\033\362O\352{Z\345\322\301ß\305\023\350\305\345*\264\065\302\375z\211\ny\030\222\b\377\vV\257\351\033\332屟:0\266v\306na:E\022>\303\363\324\335\330\345 _\375\222A\350\310@\361B\243Pǐ[\330}\276\277Y\240\061\302\313~\177U\r"..., next_out = 0x178f040 "\034"}
buffer = 0x178f040 "\034"
in = 0x7fffb3b7e5a7 "x\234\235\216\261N\303\060\020\206w?\305-LHU\355\070\315\271\002\006\220P\a\220\220\212\330\317\366%\265\232ĕ{\251\bOOڑ\221\177\270\341t\337w\277\024f\360hLͨu\323\006\252\254\213\232\235\363\326qh=\326\301\372M\353u\335T\352D\205G\001\364\206-\306\065\066M4&Zc\243%\215\036\071\022a0\270qƑ\v\212&9\344\002\303|\274\033\362O\352{Z\345\322\301ß\305\023\350\305\345*\264\065\302\375z\211\ny\030\222\b\377\vV\257\351\033\332屟:0\266v\306na:E\022>\303\363\324\335\330\345 _\375\222A\350\310@\361B\243Pǐ[\330}\276\277Y\240\061\302\313~\177U\r"...
#4 0x000000000052e1b7 in unpack_entry (p=0x850ac0, obj_offset=50877861, final_type=0x7fffff7ffb10,
final_size=0x7fffff7ffb08) at sha1_file.c:2206
w_curs = 0x83e9a0
curpos = 50877863
data = 0x0
size = 342
type = OBJ_COMMIT
small_delta_stack = {{obj_offset = 4345844982, curpos = 140737479964936, size = 140736208561400}, {
obj_offset = 8645024, curpos = 140737479965088, size = 5432450}, {obj_offset = 140737479965544,
curpos = 140737479965552, size = 50877686}, {obj_offset = 8719040, curpos = 23623984, size = 0}, {
obj_offset = 140737479965184, curpos = 140737479965032, size = 140737488348192}, {obj_offset = 8645024,
curpos = 140737479965184, size = 5432450}, {obj_offset = 140737479965640, curpos = 140737479965648,
size = 50877567}, {obj_offset = 8719040, curpos = 140736208561279, size = 343}, {obj_offset = 50877567,
curpos = 50877573, size = 127}, {obj_offset = 8645024, curpos = 140737479965280, size = 5432450}, {
obj_offset = 140737479965736, curpos = 140737479965744, size = 50877376}, {obj_offset = 8719040,
curpos = 140736208561088, size = 24703030}, {obj_offset = 4345844450, curpos = 140737479965224,
size = 140736208560868}, {obj_offset = 8645024, curpos = 140737479965376, size = 5432450}, {
obj_offset = 140737479965832, curpos = 140737479965840, size = 50877154}, {obj_offset = 8719040,
curpos = 140736208560866, size = 23620054}, {obj_offset = 4345844261, curpos = 140737479965320,
size = 140736208560679}, {obj_offset = 8645024, curpos = 140737479965472, size = 5432450}, {
obj_offset = 140737479965928, curpos = 140737479965936, size = 50876965}, {obj_offset = 8719040,
curpos = 140736208560677, size = 24703061}, {obj_offset = 4345844003, curpos = 140737479965416,
size = 140736208560421}, {obj_offset = 8645024, curpos = 140737479965568, size = 5432450}, {
obj_offset = 140737479966024, curpos = 140737479966032, size = 50876707}, {obj_offset = 8719040,
curpos = 23619712, size = 0}, {obj_offset = 140737479965664, curpos = 140737479965512,
size = 140737488348192}, {obj_offset = 8645024, curpos = 140737479965664, size = 5432450}, {
obj_offset = 140737479966120, curpos = 140737479966128, size = 50876591}, {obj_offset = 8719040,
curpos = 140736208560303, size = 333}, {obj_offset = 50876591, curpos = 50876595, size = 115}, {
obj_offset = 8645024, curpos = 140737479965760, size = 5432450}, {obj_offset = 140737479966216,
curpos = 140737479966224, size = 50876385}, {obj_offset = 8719040, curpos = 140736208560097,
size = 24702629}, {obj_offset = 4345843495, curpos = 140737479965704, size = 140736208559913}, {
obj_offset = 8645024, curpos = 140737479965856, size = 5432450}, {obj_offset = 140737479966312,
curpos = 140737479966320, size = 50876199}, {obj_offset = 8719040, curpos = 140736208559911,
size = 24702629}, {obj_offset = 4345843309, curpos = 140737479965800, size = 140736208559727}, {
obj_offset = 8645024, curpos = 140737479965952, size = 5432450}, {obj_offset = 140737479966408,
curpos = 140737479966416, size = 50876013}, {obj_offset = 8719040, curpos = 140736208559725,
size = 24490578}, {obj_offset = 4345843162, curpos = 140737479965896, size = 140736208559580}, {
obj_offset = 8645024, curpos = 140737479966048, size = 5432450}, {obj_offset = 140737479966504,
curpos = 140737479966512, size = 50875866}, {obj_offset = 8719040, curpos = 140736208559578,
size = 24490629}, {obj_offset = 4345842975, curpos = 140737479965992, size = 140736208559393}, {
obj_offset = 8645024, curpos = 140737479966144, size = 5432450}, {obj_offset = 140737479966600,
curpos = 140737479966608, size = 50875679}, {obj_offset = 8719040, curpos = 24490448, size = 0}, {
obj_offset = 140737479966240, curpos = 140737479966088, size = 140737488348192}, {obj_offset = 8645024,
curpos = 140737479966240, size = 5432450}, {obj_offset = 140737479966696, curpos = 140737479966704,
size = 50875558}, {obj_offset = 8719040, curpos = 140736208559270, size = 362}, {obj_offset = 50875558,
curpos = 50875564, size = 126}, {obj_offset = 8645024, curpos = 140737479966336, size = 5432450}, {
obj_offset = 140737479966792, curpos = 140737479966800, size = 50875395}, {obj_offset = 8719040,
curpos = 140736208559107, size = 24702213}, {obj_offset = 4345842526, curpos = 140737479966280,
size = 140736208558944}, {obj_offset = 8645024, curpos = 140737479966432, size = 5432450}, {
obj_offset = 140737479966888, curpos = 140737479966896, size = 50875230}, {obj_offset = 8719040,
curpos = 140736208558942, size = 24702206}, {obj_offset = 4345842359, curpos = 140737479966376,
size = 140736208558777}, {obj_offset = 8645024, curpos = 140737479966528, size = 5432450}, {
obj_offset = 140737479966984, curpos = 140737479966992, size = 11913437198307314359}, {
obj_offset = 8719040, curpos = 218518752100604599, size = 140737479964864}}
delta_stack = 0x7fffff7ff290
delta_stack_nr = 0
delta_stack_alloc = 64
base_from_cache = 0
#5 0x000000000052d971 in cache_or_unpack_entry (p=0x850ac0, base_offset=50877861, base_size=0x7fffff7ffb08,
type=0x7fffff7ffb10, keep_cache=1) at sha1_file.c:2011
ent = 0x821cb0 <delta_base_cache+4592>
ret = 0x1687930
#6 0x000000000052f000 in read_packed_sha1 (
sha1=0x1773e14 "k\360\205\331\004\314\063\321\024\006\231'\031\260\067\266\336M\212j", type=0x7fffff7ffb10,
size=0x7fffff7ffb08) at sha1_file.c:2614
e = {offset = 50877861, sha1 = "k\360\205\331\004\314\063\321\024\006\231'\031\260\067\266\336M\212j",
p = 0x850ac0}
data = 0x1773e14
#7 0x000000000052f285 in read_object (
sha1=0x1773e14 "k\360\205\331\004\314\063\321\024\006\231'\031\260\067\266\336M\212j", type=0x7fffff7ffb10,
size=0x7fffff7ffb08) at sha1_file.c:2662
mapsize = 140737479965264
map = 0x5295b6 <lookup_replace_object_extended+43>
buf = 0x100000000
co = 0x0
#8 0x000000000052f35d in read_sha1_file_extended (
sha1=0x1773e14 "k\360\205\331\004\314\063\321\024\006\231'\031\260\067\266\336M\212j", type=0x7fffff7ffb10,
size=0x7fffff7ffb08, flag=1) at sha1_file.c:2690
data = 0x0
p = 0x7fffffffe420
repl = 0x1773e14 "k\360\205\331\004\314\063\321\024\006\231'\031\260\067\266\336M\212j"
#9 0x000000000049ee7c in read_sha1_file (
sha1=0x1773e14 "k\360\205\331\004\314\063\321\024\006\231'\031\260\067\266\336M\212j", type=0x7fffff7ffb10,
size=0x7fffff7ffb08) at cache.h:819
No locals.
#10 0x000000000049fb19 in parse_commit (item=0x1773e10) at commit.c:316
type = 16
buffer = 0x4043e0 <_start>
size = 140737343325728
ret = 0
#11 0x000000000045c9e7 in name_rev (commit=0x1773e10, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87265, distance=87265, deref=0) at builtin/name-rev.c:30
name = 0x0
parents = 0x1
parent_number = 1
#12 0x000000000045cbed in name_rev (commit=0x1773dc8, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87264, distance=87264, deref=0) at builtin/name-rev.c:79
name = 0x1687a70
parents = 0x1687a50
parent_number = 1
#13 0x000000000045cbed in name_rev (commit=0x1773d80, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87263, distance=87263, deref=0) at builtin/name-rev.c:79
name = 0x1686900
parents = 0x1687a90
parent_number = 1
#14 0x000000000045cbed in name_rev (commit=0x1773d38, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87262, distance=87262, deref=0) at builtin/name-rev.c:79
name = 0x16868e0
parents = 0x16868c0
parent_number = 1
#15 0x000000000045cbed in name_rev (commit=0x1773cf0, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87261, distance=87261, deref=0) at builtin/name-rev.c:79
name = 0x16868a0
parents = 0x175b220
parent_number = 1
#16 0x000000000045cbed in name_rev (commit=0x1773ca8, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87260, distance=87260, deref=0) at builtin/name-rev.c:79
name = 0x175b200
parents = 0x16869e0
parent_number = 1
#17 0x000000000045cbed in name_rev (commit=0x1773c60, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87259, distance=87259, deref=0) at builtin/name-rev.c:79
name = 0x175b1e0
parents = 0x175b1c0
parent_number = 1
#18 0x000000000045cbed in name_rev (commit=0x1773c18, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87258, distance=87258, deref=0) at builtin/name-rev.c:79
name = 0x1686880
parents = 0x175b240
parent_number = 1
#19 0x000000000045cbed in name_rev (commit=0x1773bd0, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87257, distance=87257, deref=0) at builtin/name-rev.c:79
name = 0x175b1a0
parents = 0x175b180
parent_number = 1
#20 0x000000000045cbed in name_rev (commit=0x1773b88, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87256, distance=87256, deref=0) at builtin/name-rev.c:79
name = 0x175b160
parents = 0x175b330
parent_number = 1
#21 0x000000000045cbed in name_rev (commit=0x1773b40, tip_name=0x87a240 "B2G_1_0_0_20130115070201",
generation=87255, distance=87255, deref=0) at builtin/name-rev.c:79
name = 0x175b310
parents = 0x175b2f0
parent_number = 1
=================
Remove most of the name_rev calls.
See
http://people.mozilla.org/~sledru/bt-git-on-ff.txt
for the full list
=================
#87275 0x000000000045cbed in name_rev (commit=0x85d828, tip_name=0x87a240 "B2G_1_0_0_20130115070201", generation=1,
distance=1, deref=0) at builtin/name-rev.c:79
name = 0x87a290
parents = 0x87a3c0
parent_number = 1
#87276 0x000000000045cbed in name_rev (commit=0x85d7e0, tip_name=0x87a240 "B2G_1_0_0_20130115070201", generation=0,
distance=0, deref=0) at builtin/name-rev.c:79
name = 0x87a270
parents = 0x879df0
parent_number = 1
#87277 0x000000000045cfca in name_ref (path=0x87a210 "B2G_1_0_0_20130115070201",
sha1=0x843ec8 "\f\337Bk\006\356n}\275\347\217\325ݛ\350\346\001.\324\006", flags=10, cb_data=0x7fffffffdda0)
at builtin/name-rev.c:179
commit = 0x85d7e0
o = 0x85d7e0
data = 0x7fffffffdda0
can_abbreviate_output = 1
deref = 0
#87278 0x0000000000508ffd in do_one_ref (entry=0x843ec0, cb_data=0x7fffffffd290) at refs.c:650
data = 0x7fffffffd290
old_current_ref = 0x0
retval = 0
#87279 0x0000000000509387 in do_for_each_entry_in_dirs (dir1=0x843f28, dir2=0x83d888, fn=0x508f46 <do_one_ref>,
cb_data=0x7fffffffd290) at refs.c:748
e = 0x843ec0
e1 = 0x843ec0
e2 = 0x84a600
cmp = -1
retval = 5
i1 = 1
i2 = 0
__PRETTY_FUNCTION__ = "do_for_each_entry_in_dirs"
#87280 0x0000000000509299 in do_for_each_entry_in_dirs (dir1=0x83d948, dir2=0x83d6d8, fn=0x508f46 <do_one_ref>,
cb_data=0x7fffffffd290) at refs.c:720
subdir1 = 0x843f28
subdir2 = 0x83d888
e1 = 0x843f20
e2 = 0x83d880
cmp = 0
retval = 0
i1 = 1
i2 = 2
__PRETTY_FUNCTION__ = "do_for_each_entry_in_dirs"
#87281 0x0000000000509299 in do_for_each_entry_in_dirs (dir1=0x83d658, dir2=0x83d698, fn=0x508f46 <do_one_ref>,
cb_data=0x7fffffffd290) at refs.c:720
subdir1 = 0x83d948
subdir2 = 0x83d6d8
e1 = 0x83d940
e2 = 0x83d6d0
cmp = 0
retval = 0
i1 = 0
i2 = 0
__PRETTY_FUNCTION__ = "do_for_each_entry_in_dirs"
#87282 0x000000000050ad97 in do_for_each_entry (refs=0x816ea0 <ref_cache>, base=0x599616 "",
fn=0x508f46 <do_one_ref>, cb_data=0x7fffffffd290) at refs.c:1686
packed_ref_cache = 0x83d1c0
loose_dir = 0x83d698
packed_dir = 0x83d658
retval = 0
#87283 0x000000000050ae6c in do_for_each_ref (refs=0x816ea0 <ref_cache>, base=0x599616 "", fn=0x45ce44 <name_ref>,
trim=0, flags=0, cb_data=0x7fffffffdda0) at refs.c:1721
data = {base = 0x599616 "", trim = 0, flags = 0, fn = 0x45ce44 <name_ref>, cb_data = 0x7fffffffdda0}
#87284 0x000000000050af92 in for_each_ref (fn=0x45ce44 <name_ref>, cb_data=0x7fffffffdda0) at refs.c:1754
No locals.
#87285 0x000000000045d930 in cmd_name_rev (argc=0, argv=0x83d4c8, prefix=0x0) at builtin/name-rev.c:383
revs = {nr = 1, alloc = 64, objects = 0x848cb0}
all = 0
transform_stdin = 0
allow_undefined = 0
always = 0
peel_tag = 1
data = {tags_only = 1, name_only = 1, ref_filter = 0x0}
opts = {{type = OPTION_SET_INT, short_name = 0, long_name = 0x57f171 "name-only", value = 0x7fffffffdda4,
argh = 0x0, help = 0x57f17b "print only names (no SHA-1)", flags = 2, callback = 0x0, defval = 1}, {
type = OPTION_SET_INT, short_name = 0, long_name = 0x57f197 "tags", value = 0x7fffffffdda0, argh = 0x0,
help = 0x57f1a0 "only use tags to name the commits", flags = 2, callback = 0x0, defval = 1}, {
type = OPTION_STRING, short_name = 0, long_name = 0x57f1c2 "refs", value = 0x7fffffffdda8,
argh = 0x57f1c7 "pattern", help = 0x57f1d0 "only use refs matching <pattern>", flags = 0,
callback = 0x0, defval = 0}, {type = OPTION_GROUP, short_name = 0, long_name = 0x0, value = 0x0,
argh = 0x0, help = 0x57f1f1 "", flags = 0, callback = 0x0, defval = 0}, {type = OPTION_SET_INT,
short_name = 0, long_name = 0x57f1f2 "all", value = 0x7fffffffddcc, argh = 0x0,
help = 0x57f1f8 "list all commits reachable from all refs", flags = 2, callback = 0x0, defval = 1}, {
type = OPTION_SET_INT, short_name = 0, long_name = 0x57f221 "stdin", value = 0x7fffffffddc8,
argh = 0x0, help = 0x57f227 "read from stdin", flags = 2, callback = 0x0, defval = 1}, {
type = OPTION_SET_INT, short_name = 0, long_name = 0x57f0ba "undefined", value = 0x7fffffffddc4,
argh = 0x0, help = 0x57f238 "allow to print `undefined` names (default)", flags = 2, callback = 0x0,
defval = 1}, {type = OPTION_SET_INT, short_name = 0, long_name = 0x57f263 "always",
value = 0x7fffffffddc0, argh = 0x0, help = 0x57f270 "show abbreviated commit object as fallback",
flags = 2, callback = 0x0, defval = 1}, {type = OPTION_SET_INT, short_name = 0,
long_name = 0x57f29b "peel-tag", value = 0x7fffffffddbc, argh = 0x0,
help = 0x57f2a8 "dereference tags in the input (internal use)", flags = 10, callback = 0x0,
defval = 1}, {type = OPTION_END, short_name = 0, long_name = 0x0, value = 0x0, argh = 0x0, help = 0x0,
flags = 0, callback = 0x0, defval = 0}}
#87286 0x000000000042f6ec in cmd_describe (argc=1, argv=0x7fffffffe438, prefix=0x0) at builtin/describe.c:458
args = {argv = 0x83d4c0, argc = 6, alloc = 24}
contains = 1
options = {{type = OPTION_SET_INT, short_name = 0, long_name = 0x574b1d "contains", value = 0x7fffffffe1a8,
argh = 0x0, help = 0x574b28 "find the tag that comes after the commit", flags = 2, callback = 0x0,
defval = 1}, {type = OPTION_SET_INT, short_name = 0, long_name = 0x574b51 "debug",
value = 0x7e8320 <debug>, argh = 0x0, help = 0x574b58 "debug search strategy on stderr", flags = 2,
callback = 0x0, defval = 1}, {type = OPTION_SET_INT, short_name = 0, long_name = 0x574b78 "all",
value = 0x7e8324 <all>, argh = 0x0, help = 0x574b7c "use any ref", flags = 2, callback = 0x0,
defval = 1}, {type = OPTION_SET_INT, short_name = 0, long_name = 0x574b88 "tags",
value = 0x7e8328 <tags>, argh = 0x0, help = 0x574b8d "use any tag, even unannotated", flags = 2,
callback = 0x0, defval = 1}, {type = OPTION_SET_INT, short_name = 0, long_name = 0x574bab "long",
value = 0x7e832c <longformat>, argh = 0x0, help = 0x574bb0 "always use long format", flags = 2,
callback = 0x0, defval = 1}, {type = OPTION_SET_INT, short_name = 0,
long_name = 0x574bc7 "first-parent", value = 0x7e8330 <first_parent>, argh = 0x0,
help = 0x574bd4 "only follow first parent", flags = 2, callback = 0x0, defval = 1}, {
type = OPTION_CALLBACK, short_name = 0, long_name = 0x574bed "abbrev", value = 0x7dd560 <abbrev>,
argh = 0x574bf4 "n", help = 0x574bf8 "use <n> digits to display SHA-1s", flags = 1,
callback = 0x4f706c <parse_opt_abbrev_cb>, defval = 0}, {type = OPTION_SET_INT, short_name = 0,
long_name = 0x574c19 "exact-match", value = 0x7dd564 <max_candidates>, argh = 0x0,
help = 0x574c25 "only output exact matches", flags = 2, callback = 0x0, defval = 0}, {
type = OPTION_INTEGER, short_name = 0, long_name = 0x574c3f "candidates",
value = 0x7dd564 <max_candidates>, argh = 0x574bf4 "n",
help = 0x574c50 "consider <n> most recent tags (default: 10)", flags = 0, callback = 0x0, defval = 0}, {
type = OPTION_STRING, short_name = 0, long_name = 0x574c7c "match", value = 0x7e8368 <pattern>,
argh = 0x574c82 "pattern", help = 0x574c90 "only consider tags matching <pattern>", flags = 0,
callback = 0x0, defval = 0}, {type = OPTION_SET_INT, short_name = 0, long_name = 0x574cb6 "always",
value = 0x7e8370 <always>, argh = 0x0, help = 0x574cc0 "show abbreviated commit object as fallback",
flags = 2, callback = 0x0, defval = 1}, {type = OPTION_STRING, short_name = 0,
long_name = 0x574ceb "dirty", value = 0x7e8378 <dirty>, argh = 0x574cf1 "mark",
help = 0x574cf8 "append <mark> on dirty working tree (default: \"-dirty\")", flags = 1, callback = 0x0,
defval = 5721392}, {type = OPTION_END, short_name = 0, long_name = 0x0, value = 0x0, argh = 0x0,
help = 0x0, flags = 0, callback = 0x0, defval = 0}}
#87287 0x000000000040528a in run_builtin (p=0x7dab78 <commands+600>, argc=3, argv=0x7fffffffe430) at git.c:314
status = 980314466
help = 0
st = {st_dev = 0, st_ino = 0, st_nlink = 140737488347856, st_mode = 4158565948, st_uid = 32767, st_gid = 1,
__pad0 = 0, st_rdev = 0, st_size = 140737488347856, st_blksize = 140737339576408, st_blocks = 0,
st_atim = {tv_sec = 140737488347856, tv_nsec = 4211680}, st_mtim = {tv_sec = 140737351979637,
tv_nsec = 140737488348907}, st_ctim = {tv_sec = 8638752, tv_nsec = 140737488348208}, __unused = {
5676260, 140737488348907, 1}}
prefix = 0x0
#87288 0x0000000000405483 in handle_builtin (argc=3, argv=0x7fffffffe430) at git.c:487
p = 0x7dab78 <commands+600>
cmd = 0x7fffffffe6e2 "describe"
i = 25
ext = ""
#87289 0x000000000040559d in run_argv (argcp=0x7fffffffe31c, argv=0x7fffffffe320) at git.c:533
done_alias = 0
#87290 0x0000000000405739 in main (argc=3, av=0x7fffffffe428) at git.c:616
done_help = 0
was_alias = 0
argv = 0x7fffffffe430
cmd = 0x7fffffffe6e2 "describe"
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [BUG] Segfault on git describe
2014-03-19 10:48 [BUG] Segfault on git describe Sylvestre Ledru
@ 2014-03-19 12:03 ` Sylvestre Ledru
2014-03-19 22:34 ` Dragos Foianu
1 sibling, 0 replies; 5+ messages in thread
From: Sylvestre Ledru @ 2014-03-19 12:03 UTC (permalink / raw)
To: git
Sylvestre Ledru <sylvestre <at> mozilla.com> writes:
> As attachment, the backtrace. I removed about 87250 calls to the
> name_rev function. I guess that is a potential source of problem.
FYI, ulimit -s 100000 (increase the stack size) fixes the issue.
Sylvestre
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [BUG] Segfault on git describe
2014-03-19 10:48 [BUG] Segfault on git describe Sylvestre Ledru
2014-03-19 12:03 ` Sylvestre Ledru
@ 2014-03-19 22:34 ` Dragos Foianu
2014-03-20 23:33 ` Jeff King
1 sibling, 1 reply; 5+ messages in thread
From: Dragos Foianu @ 2014-03-19 22:34 UTC (permalink / raw)
To: git
Sylvestre Ledru <sylvestre <at> mozilla.com> writes:
>
> Hello,
>
> Trying to do some stats using the Firefox git repository
> (https://github.com/mozilla/gecko-dev), I found a bug
> on git describe. The following command will segfault:
> git describe --contains a9ff31aebd6dbda82a3c733a72eeeaa0b0525b96
>
> Please note that the Firefox history is a pretty long and this commit
> date is 2001.
>
> I experience this issue with the git version, and Debian packages
> (1.9.0-1 and 2.0~next.20140214-2)
>
> As attachment, the backtrace. I removed about 87250 calls to the
> name_rev function. I guess that is a potential source of problem.
>
> Full is available here:
> http://people.mozilla.org/~sledru/bt-git-on-ff.txt (21 MB)
>
> I am available to test patches if needed.
>
> Thanks,
> Sylvestre
> PS: I am not registered, please cc me.
Hello,
The name_rev function recursively calls itself which is why the backtrace is
so big. Unfortunately, for repos with long histories it can lead to Stack
Overflows. This is pretty much what happened in your case.
I tested it on my computer and I get the same results. I managed to get it
working by doubling my default stacksize:
ulimit -S -s 16192
Considering your project is a very large one and merely allocating a few
more resources fixes the problem, I'm not sure it warrants rewriting the
function to use less stack. You will have to wait for one of the maintainers
to give you a definitive answer.
All the best,
Dragos
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [BUG] Segfault on git describe
2014-03-19 22:34 ` Dragos Foianu
@ 2014-03-20 23:33 ` Jeff King
2014-03-22 10:18 ` Dragos Foianu
0 siblings, 1 reply; 5+ messages in thread
From: Jeff King @ 2014-03-20 23:33 UTC (permalink / raw)
To: Dragos Foianu; +Cc: git
On Wed, Mar 19, 2014 at 10:34:29PM +0000, Dragos Foianu wrote:
> The name_rev function recursively calls itself which is why the backtrace is
> so big. Unfortunately, for repos with long histories it can lead to Stack
> Overflows. This is pretty much what happened in your case.
>
> I tested it on my computer and I get the same results. I managed to get it
> working by doubling my default stacksize:
>
> ulimit -S -s 16192
>
> Considering your project is a very large one and merely allocating a few
> more resources fixes the problem, I'm not sure it warrants rewriting the
> function to use less stack. You will have to wait for one of the maintainers
> to give you a definitive answer.
Thanks for looking into the problem.
As a general rule, I think we are interested in reducing recursion in
functions which can go O(depth of history) or deeper. I'd say that
O(lg(depth of history)) is probably OK.
There is some precedent in 941ba8d (Eliminate recursion in
setting/clearing marks in commit list, 2012-01-14), for example.
Also, in:
abe601b (sha1_file: remove recursion in unpack_entry, 2013-03-27)
790d96c (sha1_file: remove recursion in packed_object_info,
2013-03-25)
2baad22 (index-pack: eliminate recursion in find_unresolved_deltas,
2012-01-14)
though I think those recurse in the size of delta chain, which is not
nearly so big.
So I think we'd be happy to see it converted to an iterative process
(probably with a stack on the heap). In addition to name-rev, I believe
that "tag --contains" will recurse down the longest history path, too (I
think there may have been experimental patches for the latter, but you'd
have to search the list archive).
-Peff
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [BUG] Segfault on git describe
2014-03-20 23:33 ` Jeff King
@ 2014-03-22 10:18 ` Dragos Foianu
0 siblings, 0 replies; 5+ messages in thread
From: Dragos Foianu @ 2014-03-22 10:18 UTC (permalink / raw)
To: git
Jeff King <peff <at> peff.net> writes:
>
> So I think we'd be happy to see it converted to an iterative process
> (probably with a stack on the heap). In addition to name-rev, I believe
> that "tag --contains" will recurse down the longest history path, too (I
> think there may have been experimental patches for the latter, but you'd
> have to search the list archive).
>
> -Peff
>
Alright. I'll look into it and hopefully have a patch by the end of the weekend.
-Dragos
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-03-22 10:19 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-03-19 10:48 [BUG] Segfault on git describe Sylvestre Ledru
2014-03-19 12:03 ` Sylvestre Ledru
2014-03-19 22:34 ` Dragos Foianu
2014-03-20 23:33 ` Jeff King
2014-03-22 10:18 ` Dragos Foianu
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