Ingo Molnar schrieb: > * Ingo Molnar <mingo@xxxxxxx> wrote: > >> a simple 'git fsck' still reports a ton of dangling and missing objects. >> (see it below) >> >> amongst them is the object above: >> >> missing blob af0e01d4c663a101f48614e40d006ed6272d5c36 >> >> but this does not seem to cause problems with git version 1.6.0.6 that >> i'm using now. > > hm - maybe it's unrelated, but yesterday, a few hours before the incident > i did a higher-order Octopus merge with 1.6.1, that segfaulted. > > I didnt think much of it - git often crashes with our crazy -tip tree when > i get above the magic 20 branches limit. The crash left a .git/index.lock > file around which i removed - and then forgot about the incident. I wanted > to report those crashes before but procrastinated it. > > I used git/maint snapshots because new versions of Git are much better at > doing Octopus merges. > > I've written a reproducer for git-1.6.1.1-1.fc11.i386. See the crash log > below. > > To reproduce, pick up the -tip tree as a remote: > > http://people.redhat.com/mingo/tip.git/README > > (you can run the README file as a script) > > Then do this: > > git checkout -b tmp.crash v2.6.29-rc3 > > git merge tip/x86/asm tip/x86/cleanups tip/x86/cpudetect \ > tip/x86/debug tip/x86/doc tip/x86/header-fixes \ > tip/x86/mm tip/x86/paravirt tip/x86/pat \ > tip/x86/setup-v2 tip/x86/subarch tip/x86/uaccess \ > tip/x86/urgent tip/core/percpu > > and you should see the segfault. > > interestingly i did not reproduce with the sha1's hardcoded: > > git checkout -b tmp.crash 18e352e4a73465349711a9324767e1b2453383e2 > > git merge 2d4d57db692ea790e185656516e6ebe8791f1788 a448720ca3248e8a7a426336885549d6e923fd8e b38b0665905538e76e26f2a4c686179abb1f69f6 d5e397cb49b53381e4c99a064ca733c665646de8 e56d0cfe7790fd3218ae4f6aae1335547fea8763 dbca1df48e89d8aa59254fdc10ef16c16e73d94e fb746d0e1365b7472ccc4c3d5b0672b34a092d0b 6522869c34664dd5f05a0a327e93915b1281c90d d639bab8da86d330493487e8c0fea8ca31f53427 042cbaf88ab48e11afb725541e3c2cbf5b483680 5662a2f8e7313f78d6b17ab383f3e4f04971c335 3b4b75700a245d0d48fc52a4d2f67d3155812aba bf3647c44bc76c43c4b2ebb4c37a559e899ac70e 4369f1fb7cd4cf777312f43e1cb9aa5504fc4125 > > Ingo > > --------------------> > earth4:~/tip> git merge x86/asm x86/cleanups x86/cpudetect x86/debug > x86/doc x86/header-fixes x86/mm x86/paravirt x86/pat x86/setup-v2 > x86/subarch x86/uaccess x86/urgent core/percpu > Trying simple merge with 2d4d57db692ea790e185656516e6ebe8791f1788 > Trying simple merge with a448720ca3248e8a7a426336885549d6e923fd8e > Simple merge did not work, trying automatic merge. > Auto-merging arch/x86/include/asm/io.h > Auto-merging arch/x86/include/asm/spinlock.h > Auto-merging arch/x86/kernel/mpparse.c > Auto-merging arch/x86/kernel/setup_percpu.c > Auto-merging arch/x86/mm/init_32.c > Trying simple merge with b38b0665905538e76e26f2a4c686179abb1f69f6 > Simple merge did not work, trying automatic merge. > Auto-merging arch/x86/kernel/cpu/common.c > Auto-merging arch/x86/kernel/cpu/intel.c > Auto-merging arch/x86/mm/pat.c > Trying simple merge with d5e397cb49b53381e4c99a064ca733c665646de8 > Trying simple merge with e56d0cfe7790fd3218ae4f6aae1335547fea8763 > Trying simple merge with dbca1df48e89d8aa59254fdc10ef16c16e73d94e > Trying simple merge with fb746d0e1365b7472ccc4c3d5b0672b34a092d0b > Trying simple merge with 6522869c34664dd5f05a0a327e93915b1281c90d > Simple merge did not work, trying automatic merge. > Auto-merging arch/x86/include/asm/paravirt.h > Trying simple merge with d639bab8da86d330493487e8c0fea8ca31f53427 > Simple merge did not work, trying automatic merge. > Auto-merging arch/x86/include/asm/io.h > Auto-merging arch/x86/mm/ioremap.c > Trying simple merge with 042cbaf88ab48e11afb725541e3c2cbf5b483680 > Trying simple merge with 5662a2f8e7313f78d6b17ab383f3e4f04971c335 > Trying simple merge with 3b4b75700a245d0d48fc52a4d2f67d3155812aba > Simple merge did not work, trying automatic merge. > Auto-merging arch/x86/kernel/signal.c > Trying simple merge with bf3647c44bc76c43c4b2ebb4c37a559e899ac70e > Simple merge did not work, trying automatic merge. > Auto-merging arch/x86/kernel/cpu/intel.c > Trying simple merge with 4369f1fb7cd4cf777312f43e1cb9aa5504fc4125 > /usr/libexec/git-core/git-merge-octopus: line 52: 26758 Segmentation fault > git read-tree -u -m --aggressive $common $MRT $SHA1 > Merge with strategy octopus failed. > earth4:~/tip> Current master (a34a9dbbc) with the following patch should not segfault anymore (it doesn't here), but I don't know where the magic number six is coming from. :-/ diff --git a/unpack-trees.c b/unpack-trees.c index 16bc2ca..4b02fbf 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -8,6 +8,8 @@ #include "progress.h" #include "refs.h" +#define STAGES (5 + 1) + /* * Error messages expected by scripts out of plumbing commands such as * read-tree. Non-scripted Porcelain is not required to use these messages @@ -143,7 +145,7 @@ static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_o static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o) { - struct cache_entry *src[5] = { ce, }; + struct cache_entry *src[STAGES] = { ce, }; o->pos++; if (ce_stage(ce)) { @@ -240,7 +242,7 @@ static struct cache_entry *create_ce_entry(const struct traverse_info *info, con return ce; } -static int unpack_nondirectories(int n, unsigned long mask, unsigned long dirmask, struct cache_entry *src[5], +static int unpack_nondirectories(int n, unsigned long mask, unsigned long dirmask, struct cache_entry *src[STAGES], const struct name_entry *names, const struct traverse_info *info) { int i; @@ -291,7 +293,7 @@ static int unpack_nondirectories(int n, unsigned long mask, unsigned long dirmas static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info) { - struct cache_entry *src[5] = { NULL, }; + struct cache_entry *src[STAGES] = { NULL, }; struct unpack_trees_options *o = info->data; const struct name_entry *p = names; @@ -728,7 +730,7 @@ int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o) { struct cache_entry *index; struct cache_entry *head; - struct cache_entry *remote = stages[o->head_idx + 1]; + struct cache_entry *remote; int count; int head_match = 0; int remote_match = 0; @@ -755,6 +757,9 @@ int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o) head = NULL; } + if (o->head_idx + 1 >= STAGES) + die("Too many stages (internal error)"); + remote = stages[o->head_idx + 1]; if (remote == o->df_conflict_entry) { df_conflict_remote = 1; remote = NULL; -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
