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fix for race condition - IRQ can happen between clearing the endpoint

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of the handling process and before removing the hook. The handler function
will panic then.
This commit is contained in:
Ben Gras 2009-12-01 16:46:27 +00:00
parent ad259e92af
commit 7c0cdc61bc
1 changed files with 8 additions and 9 deletions
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17
kernel/system/do_exit.c
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@ -56,6 +56,14 @@ register struct proc *rc; /* slot of process to clean up */
/* Don't clear if already cleared. */
if(isemptyp(rc)) return;
/* Check the table with IRQ hooks to see if hooks should be released. */
for (i=0; i < NR_IRQ_HOOKS; i++) {
int proc;
if (rc->p_endpoint == irq_hooks[i].proc_nr_e) {
rm_irq_handler(&irq_hooks[i]); /* remove interrupt handler */
irq_hooks[i].proc_nr_e = NONE; /* mark hook as free */
}
}
/* Remove the process' ability to send and receive messages */
clear_endpoint(rc);
@ -69,15 +77,6 @@ register struct proc *rc; /* slot of process to clean up */
*/
RTS_LOCK_SETFLAGS(rc, RTS_SLOT_FREE);
/* Check the table with IRQ hooks to see if hooks should be released. */
for (i=0; i < NR_IRQ_HOOKS; i++) {
int proc;
if (rc->p_endpoint == irq_hooks[i].proc_nr_e) {
rm_irq_handler(&irq_hooks[i]); /* remove interrupt handler */
irq_hooks[i].proc_nr_e = NONE; /* mark hook as free */
}
}
/* Release the process table slot. If this is a system process, also
* release its privilege structure. Further cleanup is not needed at
* this point. All important fields are reinitialized when the