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Miscellaneous PM fixes:

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o Don't call vm_willexit() more than once upon normal process exit
o Correct two cases of indenting of the no-discussion-possible kind
o Perform slightly stricter ptrace(2) checks:
  - process calling ptrace must be target process's parent
  - process must call wait/waitpid before using ptrace on stopped child
  - no ptrace on zombies
o Allow user processes to use ptrace(T_STOP) to stop an active child
This commit is contained in:
David van Moolenbroek 2009-07-05 22:48:18 +00:00
parent b8b8f537bd
commit 12451e6b06
3 changed files with 31 additions and 15 deletions
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4
servers/pm/forkexit.c
View file

@ -226,8 +226,8 @@ int for_trace;
* such as copying to/ from the exiting process, before it is gone.
*/
sys_nice(proc_nr_e, PRIO_STOP); /* stop the process */
if(vm_willexit(proc_nr_e) != OK) {
panic(__FILE__, "pm_exit: vm_willexit failed", proc_nr_e);
if((r=vm_willexit(proc_nr_e)) != OK) {
panic(__FILE__, "pm_exit: vm_willexit failed", r);
}
if (proc_nr_e == INIT_PROC_NR)

12
servers/pm/signal.c
View file

@ -260,7 +260,7 @@ sigset_t sig_map;
if ((rmp->mp_flags & (IN_USE | ZOMBIE)) != IN_USE) {
printf("PM: handle_ksig: %d?? zombie / not in use\n", proc_nr_e);
return;
}
}
proc_id = rmp->mp_pid;
mp = &mproc[0]; /* pretend signals are from PM */
mp->mp_procgrp = rmp->mp_procgrp; /* get process group right */
@ -517,13 +517,6 @@ doterminate:
/* Signal should not or cannot be caught. Take default action. */
if (sigismember(&ign_sset, signo)) {
return;
}
/* This process will exit, with or without dumping core.
* Announce this fact to VM.
*/
if((s=vm_willexit(rmp->mp_endpoint)) != OK) {
panic(__FILE__,"sig_proc: vm_willexit failed", s);
}
rmp->mp_sigstatus = (char) signo;
@ -745,6 +738,9 @@ register struct mproc *rmp; /* whose core is to be dumped */
* such as copying to/ from the exiting process, before it is gone.
*/
sys_nice(proc_nr_e, PRIO_STOP); /* stop the process */
if((r=vm_willexit(proc_nr_e)) != OK) {
panic(__FILE__,"dump_core: vm_willexit failed", r);
}
if(proc_nr_e != FS_PROC_NR) /* if it is not FS that is exiting.. */
{

30
servers/pm/trace.c
View file

@ -87,12 +87,29 @@ PUBLIC int do_trace()
return(OK);
}
if ((child=find_proc(m_in.pid))==NIL_MPROC || !(child->mp_flags & STOPPED)) {
return(ESRCH);
}
/* all the other calls are made by the parent fork of the debugger to
* control execution of the child
*/
if ((child=find_proc(m_in.pid))==NIL_MPROC || child->mp_parent != who_p)
return(ESRCH);
if (m_in.request == T_STOP) {
if ((r = sys_trace(T_STOP, child->mp_endpoint, 0L, (long *) 0)) != OK)
return(r);
child->mp_flags |= STOPPED;
child->mp_sigstatus = 0;
mp->mp_reply.reply_trace = 0;
return(OK);
}
/* for calls other than T_STOP, the child must be stopped and the parent
* must have waited for it
*/
if (!(child->mp_flags & STOPPED) || child->mp_sigstatus > 0)
return(ESRCH);
switch (m_in.request) {
case T_EXIT: /* exit */
pm_exit(child, (int) m_in.data, TRUE /*for_trace*/);
@ -127,7 +144,10 @@ pid_t lpid;
register struct mproc *rmp;
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++)
if (rmp->mp_flags & IN_USE && rmp->mp_pid == lpid) return(rmp);
if ((rmp->mp_flags & (IN_USE | ZOMBIE)) == IN_USE &&
rmp->mp_pid == lpid) {
return(rmp);
}
return(NIL_MPROC);
}
@ -143,7 +163,7 @@ int signo;
register struct mproc *rpmp = mproc + rmp->mp_parent;
int r;
r= sys_trace(-1, rmp->mp_endpoint, 0L, (long *) 0);
r= sys_trace(T_STOP, rmp->mp_endpoint, 0L, (long *) 0);
if (r != OK) panic("pm", "sys_trace failed", r);
rmp->mp_flags |= STOPPED;