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Re: [RFA2] Follow-up decode_line_1 crash
- To: Keith Seitz <keiths at cygnus dot com>
- Subject: Re: [RFA2] Follow-up decode_line_1 crash
- From: Fernando Nasser <fnasser at redhat dot com>
- Date: Wed, 14 Mar 2001 12:44:52 -0500
- CC: gdb-patches at sources dot redhat dot com
- Organization: Red Hat Canada
- References: <Pine.SOL.3.91.1010314081443.2126G-100000@ryobi.cygnus.com>
I have tried it and it looks OK (on Red Hat 7.0).
Let's try it.
Fernando
Keith Seitz wrote:
>
> Problem:
>
> $ gdb -nw -nx -q
> (gdb) b "foo"
> Segmentation fault (core dumped)
>
> decode_linespec_1 does something like:
>
> char *p = *argptr; (the first quote in "foo")
> if (p == '"')
> {
> p++;
> is_quote_enclosed = 1;
> }
>
> if (is_quote_enclosed)
> {
> char *closing_quote = strchr (p, '"');
> if (closing_quote && closing_quote[1] == '\0')
> *closing_quote = '\0';
> }
>
> /* so now p looks like foo with no quotes and *argptr is "foo */
>
> char *copy = (char *) alloca (p - *argptr + 1); <-- alloca of 0 bytes
> memcpy (copy, *argptr, p - *argptr); <-- copy -1 bytes
>
> Patch:
>
> Index: linespec.c
> ===================================================================
> RCS file: /cvs/cvsfiles/devo/gdb/linespec.c,v
> retrieving revision 2.4
> diff -p -p -r2.4 linespec.c
> *** linespec.c 2000/12/20 14:34:15 2.4
> --- linespec.c 2001/03/14 16:16:11
> *************** decode_line_1 (char **argptr, int funfir
> *** 611,620 ****
>
> s = NULL;
> p = *argptr;
> ! if (p[0] == '"')
> {
> is_quote_enclosed = 1;
> ! p++;
> }
> else
> is_quote_enclosed = 0;
> --- 611,620 ----
>
> s = NULL;
> p = *argptr;
> ! if (**argptr == '"')
> {
> is_quote_enclosed = 1;
> ! (*argptr)++;
> }
> else
> is_quote_enclosed = 0;
>
> Tested on RH6.2. Should be generic enough to apply to all targets. I'm no
> expert at this stuff, but a crash is Just Plain Bad (TM).
>
> Keith
--
Fernando Nasser
Red Hat Canada Ltd. E-Mail: fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario M4P 2C9