On Sep 1, 2010, at 10:47 PM, "ubizjak at gmail dot com" <gcc-bugzi...@gcc.gnu.org
> wrote:
------- Comment #10 from ubizjak at gmail dot com 2010-09-02 05:47
-------
(In reply to comment #8)
Since this doesn't backtrace in gdb, I recompiled dwarf2out.c with
the patch...
You should use bigger hammer.
Try valgrind using following procedure:
a) Create a preprocessed source
"~/gcc-build/gcc/xgcc -B ~/gcc-build/gcc -Os -S -save-temps
sprintf-chk.c"
b) fire up valgrind:
"valgrind ~/gcc-build/gcc/cc1 -Os -quiet sprintf-chk.i"
==3664== Memcheck, a memory error detector
==3664== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et
al.
==3664== Using Valgrind-3.5.0 and LibVEX; rerun with -h for
copyright info
==3664== Command: /home/uros/gcc-build/gcc/cc1 -Os -quiet sprintf-
chk.i
==3664==
==3664== Invalid read of size 8
==3664== at 0xC71730: search_line_sse2 (lex.c:394)
==3664== by 0xC71919: _cpp_clean_line (lex.c:665)
==3664== by 0xC72317: _cpp_get_fresh_line (lex.c:1878)
==3664== by 0xC73AA1: _cpp_lex_direct (lex.c:1943)
==3664== by 0xC74896: _cpp_lex_token (lex.c:1817)
==3664== by 0xC76FC7: cpp_get_token (macro.c:1240)
==3664== by 0xC7727F: cpp_get_token_with_location (macro.c:1352)
==3664== by 0x51684C: c_lex_with_flags (c-lex.c:302)
==3664== by 0x4CFAA7: c_lex_one_token (c-parser.c:204)
==3664== by 0x4DC468: c_parser_compound_statement_nostart (c-
parser.c:320)
==3664== by 0x4DEA18: c_parser_compound_statement (c-parser.c:3545)
==3664== by 0x4DBDC2: c_parser_declaration_or_fndef (c-parser.c:
1375)
==3664== Address 0x5331f50 is 5,808 bytes inside a block of size
5,815 alloc'd
==3664== at 0x4A05255: realloc (vg_replace_malloc.c:476)
==3664== by 0xC9ADAC: xrealloc (xmalloc.c:179)
==3664== by 0xC6659F: _cpp_convert_input (charset.c:1734)
==3664== by 0xC6EFA2: read_file (files.c:648)
==3664== by 0xC6F9CA: _cpp_stack_file (files.c:723)
==3664== by 0xC71190: cpp_read_main_file (init.c:570)
==3664== by 0x51B58A: c_common_post_options (c-opts.c:1124)
==3664== by 0x7DACA4: toplev_main (toplev.c:1826)
==3664== by 0x369861EC5C: (below main) (in /lib64/libc-2.12.so)
==3664==
==3664== Invalid read of size 8
==3664== at 0xC71723: search_line_sse2 (lex.c:382)
==3664== by 0xC71919: _cpp_clean_line (lex.c:665)
==3664== by 0xC72317: _cpp_get_fresh_line (lex.c:1878)
==3664== by 0xC73AA1: _cpp_lex_direct (lex.c:1943)
==3664== by 0xC74896: _cpp_lex_token (lex.c:1817)
==3664== by 0xC76FC7: cpp_get_token (macro.c:1240)
==3664== by 0xC7727F: cpp_get_token_with_location (macro.c:1352)
==3664== by 0x51684C: c_lex_with_flags (c-lex.c:302)
==3664== by 0x4CFAA7: c_lex_one_token (c-parser.c:204)
==3664== by 0x4DC468: c_parser_compound_statement_nostart (c-
parser.c:320)
==3664== by 0x4DEA18: c_parser_compound_statement (c-parser.c:3545)
==3664== by 0x4DBDC2: c_parser_declaration_or_fndef (c-parser.c:
1375)
==3664== Address 0x5331f50 is 5,808 bytes inside a block of size
5,815 alloc'd
==3664== at 0x4A05255: realloc (vg_replace_malloc.c:476)
==3664== by 0xC9ADAC: xrealloc (xmalloc.c:179)
==3664== by 0xC6659F: _cpp_convert_input (charset.c:1734)
==3664== by 0xC6EFA2: read_file (files.c:648)
==3664== by 0xC6F9CA: _cpp_stack_file (files.c:723)
==3664== by 0xC71190: cpp_read_main_file (init.c:570)
==3664== by 0x51B58A: c_common_post_options (c-opts.c:1124)
==3664== by 0x7DACA4: toplev_main (toplev.c:1826)
==3664== by 0x369861EC5C: (below main) (in /lib64/libc-2.12.so)
==3664==
==3680== ERROR SUMMARY: 4 errors from 2 contexts (suppressed: 6 from
6)
Woo-hoo?
Actually those can be safely ignored. The loads will not cross page
boundaries and then the code does not depend on the extra parts if the
buffer has correctly a null character at the end. So it is a non bug
that valgrind picks up but does not know how to handle when processing
strings with vector instructions.
--
ubizjak at gmail dot com changed:
What |Removed |Added
---
---
----------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2010-09-02 05:47:57
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45484
