Bug 12535 - decode_linespec_1 vagrind errors on ""
Summary: decode_linespec_1 vagrind errors on ""
Status: RESOLVED FIXED
Alias: None
Product: gdb
Classification: Unclassified
Component: symtab (show other bugs)
Version: HEAD
: P2 normal
Target Milestone: 10.1
Assignee: Tom Tromey
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-03-02 20:43 UTC by Jan Kratochvil
Modified: 2020-01-15 00:59 UTC (History)
2 users (show)

See Also:
Host: x86_64-fedora15-linux-gnu
Target: x86_64-fedora15-linux-gnu
Build:
Last reconfirmed:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Jan Kratochvil 2011-03-02 20:43:46 UTC 
valgrind ./gdb -nx -ex 'python gdb.decode_line("")'

First it wrongly detects IS_QUOTED == 1, one should check the code more for it.

==19361== Invalid read of size 1
==19361==    at 0x6A9628: locate_first_half (linespec.c:1146)
==19361==    by 0x6A8C3A: decode_line_1 (linespec.c:871)
==19361==    by 0x628404: gdbpy_decode_line (python.c:457)
==19361==    by 0x5E15DCC: PyEval_EvalFrameEx (ceval.c:4072)
==19361==    by 0x5E1799C: PyEval_EvalCodeEx (ceval.c:3312)
==19361==    by 0x5E17AD1: PyEval_EvalCode (ceval.c:671)
==19361==    by 0x5E31BDB: run_mod (pythonrun.c:1354)
==19361==    by 0x5E327FC: PyRun_StringFlags (pythonrun.c:1317)
==19361==    by 0x5E3333A: PyRun_SimpleStringFlags (pythonrun.c:970)
==19361==    by 0x627BA3: python_command (python.c:205)
==19361==    by 0x604DE4: do_cfunc (cli-decode.c:67)
==19361==    by 0x607F69: cmd_func (cli-decode.c:1777)
==19361==    by 0x48D2C5: execute_command (top.c:428)
==19361==    by 0x6CB967: catch_command_errors (exceptions.c:537)
==19361==    by 0x4836F4: captured_main (main.c:909)
==19361==    by 0x6CB8CC: catch_errors (exceptions.c:521)
==19361==    by 0x483789: gdb_main (main.c:942)
==19361==    by 0x4823C2: main (gdb.c:35)
==19361==  Address 0xd692ce1 is 0 bytes after a block of size 1 alloc'd
==19361==    at 0x4C2840D: malloc (vg_replace_malloc.c:236)
==19361==    by 0x490F47: xmalloc (utils.c:1475)
==19361==    by 0xDE2455: xstrdup (xstrdup.c:34)
==19361==    by 0x6283C0: gdbpy_decode_line (python.c:454)
==19361==    by 0x5E15DCC: PyEval_EvalFrameEx (ceval.c:4072)
==19361==    by 0x5E1799C: PyEval_EvalCodeEx (ceval.c:3312)
==19361==    by 0x5E17AD1: PyEval_EvalCode (ceval.c:671)
==19361==    by 0x5E31BDB: run_mod (pythonrun.c:1354)
==19361==    by 0x5E327FC: PyRun_StringFlags (pythonrun.c:1317)
==19361==    by 0x5E3333A: PyRun_SimpleStringFlags (pythonrun.c:970)
==19361==    by 0x627BA3: python_command (python.c:205)
==19361==    by 0x604DE4: do_cfunc (cli-decode.c:67)
==19361==    by 0x607F69: cmd_func (cli-decode.c:1777)
==19361==    by 0x48D2C5: execute_command (top.c:428)
==19361==    by 0x6CB967: catch_command_errors (exceptions.c:537)
==19361==    by 0x4836F4: captured_main (main.c:909)
==19361==    by 0x6CB8CC: catch_errors (exceptions.c:521)
==19361==    by 0x483789: gdb_main (main.c:942)
==19361==    by 0x4823C2: main (gdb.c:35)
==19361==
Comment 1 Tom Tromey 2020-01-04 21:46:52 UTC 
Sending a patch.
Comment 2 Sourceware Commits 2020-01-15 00:58:38 UTC 
The master branch has been updated by Tom Tromey <tromey@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ff47f4f06d296b672337e2c7363a745cd2725f58

commit ff47f4f06d296b672337e2c7363a745cd2725f58
Author: Tom Tromey <tom@tromey.com>
Date:   Sat Dec 21 09:51:05 2019 -0700

    Fix valgrind error from gdb.decode_line
    
    PR symtab/12535 points out that gdb.decode_line("") will cause a
    valgrind report.
    
    I think the empty linespec does not really make sense.  So, this patch
    changes gdb.decode_line to treat a whitespace-only linespec the same
    as a non-existing argument.
    
    gdb/ChangeLog
    2020-01-14  Tom Tromey  <tom@tromey.com>
    
    	PR symtab/12535:
    	* python/python.c (gdbpy_decode_line): Treat empty string the same
    	as no argument.
    
    gdb/testsuite/ChangeLog
    2020-01-14  Tom Tromey  <tom@tromey.com>
    
    	PR symtab/12535:
    	* gdb.python/python.exp: Test decode_line with empty string
    	argument.
    
    Change-Id: I1d95812b4b7a21d69a3e9afd05b9e3141a931897
Comment 3 Tom Tromey 2020-01-15 00:59:05 UTC 
Fixed.