source line mapping in .s

I see no problems with 5.3 either:

$ CC -S a.c

$ cat a.s

<skip>

/ File a.c:

/ Line 8

/ Line 9

pushl$300

callmalloc

addl$4,%esp

movl%eax, -8(%ebp)

/ Line 10

movl$0, -4(%ebp)

jmp.L3

.align 4

<skip>

MaximKartasheva at 2007-7-7 15:49:15 >

The process in question cannot be run/debugged in a stand-alone mode. It works as a part of a certain system and gets its input from a few other processes that run along with it. We don't always have access to the lab where this system runs and we don't have a simulator for the same. Sometimes all we have is a corefile and the pstack.

_s_r_s_a at 2007-7-7 15:49:15 >

I can easily get a pstack from the corefile, but I cannot execute the program/core in dbx because the program during initialization checks for a certain environment, connects to a few other processes which are available only on the target environment and not on my development/test environment.

_s_r_s_a at 2007-7-7 15:49:15 >

I sometimes run into a similar situation where I have DTrace-generated

stack traces which provide symbol+offset address that I'd like to map to

high level source lines.

I could probably re-run under dbx to the same point that triggered the

DTrace probe, but it wouldn't always be trivial. [If it were trivial,

I wouldn't have needed to use DTrace to track it down :-) ]

I'd *like* to be able to use some hypothetical dbx command like:

(dbx) lineinfo beta+0x344

==> beta(), line 541 in "supportutils.c"

I used to use the "list -i" command:

(dbx) list -i beta

... source + disassembly listing ...

and manually find the symbol+offset that I'm interested in. Now I use a

"hack" which I have encapsulated into a script which runs the executable

up to "_start" (just to load the shared objects without running any of the

logic of the program), then set the PC to the address in question and

issue a "where" or "list" command:

(dbx) stop in _start

(dbx) run

(dbx) assign $pc=beta+0x344

(dbx) where

=>[1] beta(sz = 0), line 541 in "supportutils.c"

This occasionally works, but usually I have to execute a single "stepi"

command before the high level line number is available. I'm not sure why

that "stepi" is needed.

(dbx) stepi

(dbx) where

=>[1] beta(sz = 0), line 541 in "supportutils.c"

I cringe at executing some arbitrary instruction from the target function

using the "_start" stack frame, but this hack generally seems to do what I

want.

I suspect I've built a Rube Goldberg solution to a simple problem, so I'd

like to ask if there's a simple/robust way to do this mapping within dbx.

-morgan

morganherringtona at 2007-7-21 15:38:34 >