ed SEGV
Currently, my copy of ed is throwing SEGV; gdb says this is caused by a
pattern pointer being fed to regexec as 0xffffffff, so it makes some sense.
What doesn't make sense is that the pointer is aquiring this value after
being used in a prior call to regexec - which prototypes that argument as
a (const regex_t *).
I have attached the log of a GDB run over it, to share the confusion...
--
***************************************************************************
Joel Baker System Administrator - lightbearer.com
lucifer@lightbearer.com http://users.lightbearer.com/lucifer/
root@deb-bsd:/tmp/Hard/ed-0.2$ cat ed-test/comment.ed
#!/bin/sh -
/tmp/Hard/ed-0.2/ed - <<'EOT'
H
r /tmp/Hard/ed-0.2/testsuite/comment.d
# lines beginning with a `#' should be ignored
g/./# including in global commands \
s/l/x/\
# and in the command list \
s/x/y/
w comment.o
EOT
root@deb-bsd:/tmp/Hard/ed-0.2$ gdb ./ed
GNU gdb 5.1
Copyright 2001 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-unknown-netbsdelf1.5"...
(gdb) set args -
(gdb) break substitute_matching_text
Breakpoint 1 at 0x8050c84: file sub.c, line 190.
(gdb) run
Starting program: /tmp/Hard/ed-0.2/./ed -
H
r /tmp/Hard/ed-0.2/testsuite/comment.d
# lines beginning with a `#' should be ignored
g/./# including in global commands \
s/l/x/\
# and in the command list \
s/x/y/
Breakpoint 1, substitute_matching_text (pat=0x8055180, lp=0x80550a0, gflag=1,
kth=0) at sub.c:190
190 {
(gdb) display pat
1: pat = (pattern_t *) 0x8055180
(gdb) display *pat
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
(gdb) n
191 int off = 0;
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
192 int changed = 0;
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
193 int matchno = 0;
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
194 int i = 0;
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
199 if ((txt = get_sbuf_line (lp)) == NULL)
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
201 if (isbinary)
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
203 eot = txt + lp->len;
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
204 if (!regexec (pat, txt, SE_MAX, rm, 0))
2: *pat = {buffer = 0xf265 <Error reading address 0xf265: Invalid argument>,
allocated = 0, used = 0, syntax = 134575616, fastmap = 0x0, translate = 0x0,
re_nsub = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 0}
1: pat = (pattern_t *) 0x8055180
(gdb) n
208 if (!kth || kth == ++matchno)
2: *pat = Error accessing memory address 0xffffffff: Invalid argument.
Disabling display 2 to avoid infinite recursion.
(gdb) print pat
$1 = (pattern_t *) 0xffffffff
(gdb) quit
The program is running. Exit anyway? (y or n) y
root@deb-bsd:/tmp/Hard/ed-0.2$
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