# Potential bug in pack-objects.c 3 messages from 2019-01-21 to 2019-01-22. Participants: Alex Netkachov, Jeff King. Thread: https://gitlist.dev/t/50278 ## Alex Netkachov, 2019-01-21 22:10 Subject: Potential bug in pack-objects.c Message-ID: URL: https://gitlist.dev/e/CAGAu0HVeQFA_O8_hsZbzRi9X35fF3DAeUaSd993JF%3DNTwaZP1Q%40mail.gmail.com ``` Hi, The most recent version of git crashes on gc command on my repository. I've tracked it down to the segmentation fault in pack-objects.c while running this command in the debugger: gdb --args /usr/src/git/git-pack-objects.exe --local --delta-base-offset .git/objects/pack/.tmp-14368-pack --keep-true-parents --honor-pack-keep --non-empty --all --reflog --indexed-objects --unpack-unreachable=2.weeks.ago --threads=1 It stops here: #0 0x00007ff88b11de0e in ntdll!RtlLockHeap () from C:\Windows\SYSTEM32\ntdll.dll #1 0x00007ff88b11b7e4 in ntdll!RtlEnterCriticalSection () from C:\Windows\SYSTEM32\ntdll.dll #2 0x000000000047027c in oe_get_size_slow (pack=0x73fc20 , e=0x7ff5f7b03428) at builtin/pack-objects.c:1996 #3 0x000000000046ba27 in oe_set_size (pack=0x73fc20 , e=0x7ff5f7b03428, size=2987958784) at ./pack-objects.h:362 #4 0x000000000046f556 in check_object (entry=0x7ff5f7b03428) at builtin/pack-objects.c:1564 #5 0x000000000046ff63 in get_object_details () at builtin/pack-objects.c:1873 #6 0x0000000000471c11 in prepare_pack (window=10, depth=50) at builtin/pack-objects.c:2615 #7 0x0000000000474705 in cmd_pack_objects (argc=0, argv=0x2e30a48, prefix=0x0) at builtin/pack-objects.c:3491 #8 0x0000000000402e3b in run_builtin (p=0x680700 , argc=12, argv=0x2e30a48) at git.c:421 #9 0x00000000004031f6 in handle_builtin (argc=12, argv=0x2e30a48) at git.c:653 #10 0x000000000040376b in cmd_main (argc=12, argv=0x2e30a48) at git.c:799 #11 0x00000000004bfb2f in main (argc=12, argv=0x2e30a48) at common-main.c:45 On the location builtin/pack-objects.c:1996 the code tries to set read_lock (pthread_mutex_lock(&read_mutex)) and fails. I suspect that read_mutex is not initialised yet. It is initialised in init_threaded_search, which is called later in prepare_pack (through ll_find_deltas). Kind Regards, Alex Netkachov ``` ## Jeff King, 2019-01-22 07:29 Subject: Re: Potential bug in pack-objects.c Message-ID: <20190122072946.GB28975@sigill.intra.peff.net> URL: https://gitlist.dev/e/20190122072946.GB28975%40sigill.intra.peff.net In-Reply-To: ``` On Mon, Jan 21, 2019 at 10:10:16PM +0000, Alex Netkachov wrote: > On the location builtin/pack-objects.c:1996 the code tries to set > read_lock (pthread_mutex_lock(&read_mutex)) and fails. I suspect that > read_mutex is not initialised yet. It is initialised in > init_threaded_search, which is called later in prepare_pack (through > ll_find_deltas). This sounds like the same bug being discussed in: http://public-inbox.org/git/20190118022736.36832-1-phogg@novamoon.net/ -Peff ``` ## Alex Netkachov, 2019-01-22 15:33 Subject: Re: Potential bug in pack-objects.c Message-ID: URL: https://gitlist.dev/e/CAGAu0HW%3DN2nQr7zq_EVpegJDc6_womFDCLU5SCoCQw6cmzw8xg%40mail.gmail.com In-Reply-To: <20190122072946.GB28975@sigill.intra.peff.net> ``` On Tue, 22 Jan 2019 at 07:29, Jeff King wrote: > > On Mon, Jan 21, 2019 at 10:10:16PM +0000, Alex Netkachov wrote: > > > On the location builtin/pack-objects.c:1996 the code tries to set > > read_lock (pthread_mutex_lock(&read_mutex)) and fails. I suspect that > > read_mutex is not initialised yet. It is initialised in > > init_threaded_search, which is called later in prepare_pack (through > > ll_find_deltas). > > This sounds like the same bug being discussed in: > > http://public-inbox.org/git/20190118022736.36832-1-phogg@novamoon.net/ It is exactly the same thing. Thank you. Hope it will be applied soon and released. Kind regards, Alex ```