picnoir/glibc
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

2008-03-25 Roland McGrath <roland@redhat.com>

Browse source 
* structs.def: Add pid field of struct pthread.
	* td_ta_thr_iter.c (iterate_thread_list): Take new arg MATCH_PID.
	If a thread's pid does not match nor is < 0 while its tid matches
	nor is < 0 and equal to -MATCH_PID, ignore it.
	* td_thr_validate.c (td_thr_validate): Validate thread's pid/tid.
This commit is contained in:
Roland McGrath 2008-03-26 08:21:10 +00:00
parent 87b9b50f0d
commit d11dc9ecb7
3 changed files with 73 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
nptl_db/structs.def
View file

@ -1,5 +1,5 @@
/* List of types and symbols in libpthread examined by libthread_db.
Copyright (C) 2003, 2006, 2007 Free Software Foundation, Inc.
Copyright (C) 2003, 2006, 2007, 2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -27,6 +27,7 @@ DB_STRUCT (pthread)
DB_STRUCT_FIELD (pthread, list)
DB_STRUCT_FIELD (pthread, report_events)
DB_STRUCT_FIELD (pthread, tid)
DB_STRUCT_FIELD (pthread, pid)
DB_STRUCT_FIELD (pthread, start_routine)
DB_STRUCT_FIELD (pthread, cancelhandling)
DB_STRUCT_FIELD (pthread, schedpolicy)

71
nptl_db/td_ta_thr_iter.c
View file

@ -1,5 +1,5 @@
/* Iterate over a process's threads.
Copyright (C) 1999,2000,2001,2002,2003,2004,2007
Copyright (C) 1999,2000,2001,2002,2003,2004,2007,2008
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
@ -25,7 +25,7 @@
static td_err_e
iterate_thread_list (td_thragent_t *ta, td_thr_iter_f *callback,
void *cbdata_p, td_thr_state_e state, int ti_pri,
psaddr_t head, bool fake_empty)
psaddr_t head, bool fake_empty, pid_t match_pid)
{
td_err_e err;
psaddr_t next, ofs;
@ -78,28 +78,48 @@ iterate_thread_list (td_thragent_t *ta, td_thr_iter_f *callback,
if (ps_pdread (ta->ph, addr, copy, ta->ta_sizeof_pthread) != PS_OK)
return TD_ERR;
err = DB_GET_FIELD_LOCAL (schedpolicy, ta, copy, pthread,
schedpolicy, 0);
if (err != TD_OK)
break;
err = DB_GET_FIELD_LOCAL (schedprio, ta, copy, pthread,
schedparam_sched_priority, 0);
if (err != TD_OK)
break;
/* Now test whether this thread matches the specified conditions. */
/* Only if the priority level is as high or higher. */
int descr_pri = ((uintptr_t) schedpolicy == SCHED_OTHER
? 0 : (uintptr_t) schedprio);
if (descr_pri >= ti_pri)
/* Verify that this thread's pid field matches the child PID.
If its pid field is negative, it's about to do a fork or it
is the sole thread in a fork child. */
psaddr_t pid;
err = DB_GET_FIELD_LOCAL (pid, ta, copy, pthread, pid, 0);
if (err == TD_OK && (pid_t) (uintptr_t) pid < 0)
{
/* Yep, it matches. Call the callback function. */
td_thrhandle_t th;
th.th_ta_p = (td_thragent_t *) ta;
th.th_unique = addr;
if (callback (&th, cbdata_p) != 0)
return TD_DBERR;
if (-(pid_t) (uintptr_t) pid == match_pid)
/* It is about to do a fork, but is really still the parent PID. */
pid = (psaddr_t) (uintptr_t) match_pid;
else
/* It must be a fork child, whose new PID is in the tid field. */
err = DB_GET_FIELD_LOCAL (pid, ta, copy, pthread, tid, 0);
}
if (err != TD_OK)
break;
if ((pid_t) (uintptr_t) pid == match_pid)
{
err = DB_GET_FIELD_LOCAL (schedpolicy, ta, copy, pthread,
schedpolicy, 0);
if (err != TD_OK)
break;
err = DB_GET_FIELD_LOCAL (schedprio, ta, copy, pthread,
schedparam_sched_priority, 0);
if (err != TD_OK)
break;
/* Now test whether this thread matches the specified conditions. */
/* Only if the priority level is as high or higher. */
int descr_pri = ((uintptr_t) schedpolicy == SCHED_OTHER
? 0 : (uintptr_t) schedprio);
if (descr_pri >= ti_pri)
{
/* Yep, it matches. Call the callback function. */
td_thrhandle_t th;
th.th_ta_p = (td_thragent_t *) ta;
th.th_unique = addr;
if (callback (&th, cbdata_p) != 0)
return TD_DBERR;
}
}
/* Get the pointer to the next element. */
@ -135,17 +155,18 @@ td_ta_thr_iter (const td_thragent_t *ta_arg, td_thr_iter_f *callback,
have to iterate over both lists separately. We start with the
list of threads with user-defined stacks. */
pid_t pid = ps_getpid (ta->ph);
err = DB_GET_SYMBOL (list, ta, __stack_user);
if (err == TD_OK)
err = iterate_thread_list (ta, callback, cbdata_p, state, ti_pri,
list, true);
list, true, pid);
/* And the threads with stacks allocated by the implementation. */
if (err == TD_OK)
err = DB_GET_SYMBOL (list, ta, stack_used);
if (err == TD_OK)
err = iterate_thread_list (ta, callback, cbdata_p, state, ti_pri,
list, false);
list, false, pid);
return err;
}

26
nptl_db/td_thr_validate.c
View file

@ -1,5 +1,6 @@
/* Validate a thread handle.
Copyright (C) 1999,2001,2002,2003,2004,2007 Free Software Foundation, Inc.
Copyright (C) 1999,2001,2002,2003,2004,2007,2008
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
@ -81,5 +82,28 @@ td_thr_validate (const td_thrhandle_t *th)
err = TD_OK;
}
if (err == TD_OK)
{
/* Verify that this is not a stale element in a fork child. */
pid_t match_pid = ps_getpid (th->th_ta_p->ph);
psaddr_t pid;
err = DB_GET_FIELD (pid, th->th_ta_p, th->th_unique, pthread, pid, 0);
if (err == TD_OK && (pid_t) (uintptr_t) pid < 0)
{
/* This was a thread that was about to fork, or it is the new sole
thread in a fork child. In the latter case, its tid was stored
via CLONE_CHILD_SETTID and so is already the proper child PID. */
if (-(pid_t) (uintptr_t) pid == match_pid)
/* It is about to do a fork, but is really still the parent PID. */
pid = (psaddr_t) (uintptr_t) match_pid;
else
/* It must be a fork child, whose new PID is in the tid field. */
err = DB_GET_FIELD (pid, th->th_ta_p, th->th_unique,
pthread, tid, 0);
}
if (err == TD_OK && (pid_t) (uintptr_t) pid != match_pid)
err = TD_NOTHR;
}
return err;
}