Re: What's in git.git

From: Linus Torvalds <torvalds@osdl.org>
Date: May 10, 2006, 16:48 UTC
Message-ID: <Pine.LNX.4.64.0605100919250.3718@g5.osdl.org>
In-Reply-To: <Pine.LNX.4.64.0605101012250.24505@localhost.localdomain>

On Wed, 10 May 2006, Nicolas Pitre wrote:

Show 5 quoted lines

> 
> When linking with Electric Fence I can reproduce the segfault on Linux 
> as well.
> 
> Looking into it now.

Yeah, I get

	#0  0x1000bfe4 in create_delta (index=0xf7d758a0, trg_buf=0xf7d72eb8, trg_size=327, delta_size=0xffb422b4, 
	    max_size=143) at diff-delta.c:308
	#1  0x10005734 in try_delta (trg=0xf7fdbfa0, src=0xf7fdbf94, src_index=0xf7d758a0, max_depth=10)
	    at pack-objects.c:1049
	#2  0x10005b04 in find_deltas (list=0xf7e32f54, window=11, depth=10) at pack-objects.c:1128
	#3  0x10005ca0 in prepare_pack (window=10, depth=10) at pack-objects.c:1161
	#4  0x1000677c in main (argc=3, argv=0xffb436e4) at pack-objects.c:1359

ie the "entry" chain seems to be corrupt in create_delta.

Actually, it's not even the chain: it's the very first entry:

	(gdb) p index->hash[i]
	$2 = (struct index_entry *) 0xf7d7385c
	(gdb) p entry
	$3 = (struct index_entry *) 0xf7d7385c

and it's not a random value - it looks perfectly valid. As do all the other index hash entries. It's just that the index hash entries seem to all have been freed, so accessing them causes a SIGSEV!

			Linus