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Re: Watchpoints in multithreaded programs
- From: Steve Freeland <caucasatron at yahoo dot ca>
- To: Daniel Jacobowitz <drow at false dot org>
- Cc: gdb at sources dot redhat dot com
- Date: Mon, 2 Oct 2006 20:53:10 -0700 (PDT)
- Subject: Re: Watchpoints in multithreaded programs
Is there anything particularly wrong with just setting the watchpoint individually in each of
the threads? I haven't a clue about portability, but on I've checked on i386 Linux and this
seems to work... at least, it solves my problem. I can clean this up and make it submittable
as a patch, but first I'd like to know if there's a problem with it conceptually, as I've never
worked with gdb internals before:
struct i386_linux_dr_operation
{
int regnum;
unsigned long value;
};
static int i386_linux_dr_set_for_tid(int tid, int regnum, unsigned long value)
{
int result = 0;
errno = 0;
ptrace (PTRACE_POKEUSER, tid,
offsetof (struct user, u_debugreg[regnum]), value);
if (errno != 0)
{
perror_with_name (_("Couldn't write debug register"));
result = 1;
}
return result;
}
static int i386_linux_perform_dr_operation(struct thread_info *t, void *arg)
{
struct i386_linux_dr_operation *op = arg;
return i386_linux_dr_set_for_tid(TIDGET(t->ptid), op->regnum, op->value);
}
static void
i386_linux_dr_set (int regnum, unsigned long value)
{
int tid = TIDGET (inferior_ptid);
if (tid == 0)
{
i386_linux_dr_set_for_tid(PIDGET(inferior_ptid), regnum, value);
}
else
{
struct i386_linux_dr_operation op = { regnum, value };
iterate_over_threads(i386_linux_perform_dr_operation, &op);
}
}
----- Original Message ----
From: Daniel Jacobowitz <drow@false.org>
To: Steve Freeland <caucasatron@yahoo.ca>
Cc: gdb@sources.redhat.com
Sent: Sunday, October 1, 2006 7:24:43 PM
Subject: Re: Watchpoints in multithreaded programs
On Sun, Oct 01, 2006 at 02:23:27PM -0700, Steve Freeland wrote:
> So... I'm a bit confused. Is the manual out of date? Did the
> "watchthreads" patch never make it into mainline builds for some
> reason?
It never did. Discussion trailed off and we never heard anything else
about it from the submitter.
I recall seeing a few weeks ago that there is an updated version in
the Red Hat SRPMs. Could any of the list subscribers from Red Hat
comment - is that version fit for submission?
--
Daniel Jacobowitz
CodeSourcery