[vox-tech] Mystery Segmentation Faults: grep and sed

[Dylan Beaudette]

Good morning!

Last night all was well with my G4 powerbook, even after a rather large
number of updates from and apt-get update && apt-get upgrade.

However, this morning, I noticed some strange segmentation faults when the
machine was starting. They all seemed to be happening after a sed command
was issued. I tried manually using sed and grep, and both now seem to be
giving segementation faults!

here is a quick example with the output of strace included:

--------------------snip----------------------
dylan at pbg4:~$ echo "food" | grep -i food
Segmentation fault

dylan at pbg4:~$ strace echo "food" | grep -i food
execve("/bin/echo", ["echo", "food"], [/* 27 vars */]) = 0
uname({sys="Linux", node="pbg4", ...})  = 0
brk(0)                                  = 0x10013680
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x30016000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or
directory)
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or
directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=72216, ...}) = 0
mmap(NULL, 72216, PROT_READ, MAP_PRIVATE, 3, 0) = 0x30027000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or
directory)
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\24\0\0\0\1\0\1\322"...,
512) = 512
fstat64(3, {st_mode=S_IFREG|0644, st_size=1298544, ...}) = 0
mmap(0xfea1000, 1370024, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0xfea1000
mprotect(0xffd3000, 116648, PROT_NONE)  = 0
mmap(0xffe1000, 49152, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED, 3, 0x130000) = 0xffe1000
mmap(0xffed000, 10152, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xffed000
close(3)                                = 0
munmap(0x30027000, 72216)               = 0
brk(0)                                  = 0x10013680
brk(0x10034680)                         = 0x10034680
brk(0)                                  = 0x10034680
brk(0x10035000)                         = 0x10035000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=3202928, ...}) = 0
mmap2(NULL, 2097152, PROT_READ, MAP_PRIVATE, 3, 0) = 0x30027000
close(3)                                = 0
fstat64(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x30017000
write(1, "food\n", 5)                   = -1 EPIPE (Broken pipe)
--- SIGPIPE (Broken pipe) @ 0 (0) ---
+++ killed by SIGPIPE +++
Segmentation fault
-----------------------snip-----------------------

can anyone make any sense of all of this? for some reason my sed and grep
broke between yesterday night and this morning.... and i imagine that it
had something to do with the update last night.

any ideas would be greatly appreciated!

thanks,

Dylan