Debugging core file through disassemble code

My program got cored and in the same frame I ran cmd given below and got the o/p
dbx> dis
0x0008a754: hellworld+0x0024: or %l1, %g0, %o2
0x0008a758: hellworld+0x0028: st %g0, [%fp - 0x4]
0x0008a75c: hellworld+0x002c: st %g0, [%fp - 0x8c]
0x0008a760: hellworld+0x0030: stb %g0, [%fp - 0x8d]
0x0008a764: hellworld+0x0034: stb %g0, [%fp - 0x8e]
0x0008a768: hellworld+0x0038: stb %g0, [%fp - 0x8f]
0x0008a76c: hellworld+0x003c: sth %g0, [%fp - 0x92]
0x0008a770: hellworld+0x0040: add %fp, -0x80, %l0
0x0008a774: hellworld+0x0044: st %l0, [%fp - 0x8c]
How to find where the segmentation fault occur and why
-Neo

Neo12051 wrote:
My program got cored and in the same frame I ran cmd given below and got the o/p
How to find where the segmentation fault occur and why Dbx prints this information right after it loads all modules:
$ dbx - core
Reading ld.so.1
Reading libm.so.2
t@1 (l@1) program terminated by signal ABRT (Abort)
0xfdda5067: _kill+0x0007: jb __cerror [ 0xfdd20510, .-0x84b57 ]The last two lines describe reason (signal ABRT) and location (0xfdda5067) of the fault.
High level reason for segmentation fault (SIGSEGV) is absence of mapped memory at certain location the process is trying to access. Most frequent reason is a variation of NULL pointer dereferece (address 0x0 and other close-to-zero addresses are always left unmapped for this very reason). When your program, for example, tries to write to a string ptr that it forgot to initialize properly, it ends up with something like this:
0x00010e20: main+0x0010: stb %o1, [%o0](store byte from register %o1 into memory location addressed by register %o0) while value of %o0 points to unmapped memory:
(dbx:main) print $o0
$o0 = 20ULLAddress 20 is so close to zero that it suggest a bug like uninitialized array of characters, which 20th element is being assigned.
The code you provided looks like initialization of a few small locals and can only fail if %fp (Frame Pointer) contains garbage. Therefore if location of SEGV is somewhere in that code (you didn't give this information, so I'm only guessing), I'd suggest looking for writing past array (string) bounds type of bug. If a function called from this one wrote past its local array bounds, it could've overwritten value of frame pointer saved on stack.
It's hard to say more without knowing value of all relevant registers at location of failure (regs command will help with that).

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Hi ,
I have already tried the changes suggested by you . i.e chnage the permissions and also to replace the
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Here are a few questions one of our developers asked me
to post:
There are some things I don't understand about these core files.
(I get this dbx message examining the core file: dbx: internal warning: writable memory segment 0xfe750000[188416] of size 0 in core)
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[5] 0x4aee0(0x4bfd8, 0x0, 0xff000000, 0x0, 0x0, 0xfe7f2000), at 0x4aedf
[6] 0x2380c(0x1, 0x1084, 0xfe797cc0, 0x0, 0xfe7f2000, 0x1000), at 0x2380b
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[2] 0xfeee5724(0xffbff1ac, 0xfe47c000, 0x0, 0x0, 0xffbff1a0, 0x4bb1c), at 0xfeee5723
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1. Why is where on thread 5 not reporting the SEGV?
2. Why is thread 1 in the exit handle when some threads have not yet exited?
3. Why is thread 1 not showing any stack above the exit call?
How do I get information on these questions?
Thanks in advance.
-- prasad

which version of dbx are you using?
A message about "size 0" can sometimes mean that
your core file was truncated by a core limit that is set
too low. That can cause missing information.
1. Why is where on thread 5 not reporting the SEGV?I don't know. This seems like a bug, but not a serious one.
You know there is a seg fault from the "threads" command.
2. Why is thread 1 in the exit handle when some threads have not yet exited?The program can call exit() whenever it wants to. At that
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