diff options
Diffstat (limited to 'sys/kern/kern_fork.c')
| -rw-r--r-- | sys/kern/kern_fork.c | 73 |
1 files changed, 72 insertions, 1 deletions
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c index 2ac1849..f6bb284 100644 --- a/sys/kern/kern_fork.c +++ b/sys/kern/kern_fork.c @@ -36,7 +36,7 @@ * SUCH DAMAGE. * * @(#)kern_fork.c 8.6 (Berkeley) 4/8/94 - * $Id: kern_fork.c,v 1.22 1996/06/12 05:07:30 gpalmer Exp $ + * $Id: kern_fork.c,v 1.23 1996/07/31 09:26:34 davidg Exp $ */ #include "opt_ktrace.h" @@ -64,6 +64,16 @@ static int fork1 __P((struct proc *p, int flags, int *retval)); +/* + * callout list for things to do at fork time + */ +typedef struct fork_list_element { + struct fork_list_element *next; + forklist_fn function; +} *fle_p; + +static fle_p fork_list; + #ifndef _SYS_SYSPROTO_H_ struct fork_args { int dummy; @@ -114,6 +124,7 @@ fork1(p1, flags, retval) struct proc *newproc; int count; static int nextpid, pidchecked = 0; + fle_p ep = fork_list; if ((flags & RFPROC) == 0) return (EINVAL); @@ -335,6 +346,16 @@ again: } /* + * Both processes are set up, + * check if any LKMs want to adjust anything + * What if they have an error? XXX + */ + while(ep) { + (*ep->function)(p1,p2,flags); + ep = ep->next; + } + + /* * Make child runnable and add to run queue. */ (void) splhigh(); @@ -363,3 +384,53 @@ again: retval[1] = 0; return (0); } + + +/********************************************************* + * general routines to handle adding/deleting items on the + * fork callout list + ***** + * Take the arguments given and put them onto the fork callout list. + * However first make sure that it's not already there. + * returns 0 on success. + */ +int +at_fork(forklist_fn function) +{ + fle_p ep; + if(rm_at_fork(function)) { + printf("fork callout entry already present\n"); + } + ep = malloc(sizeof(*ep),M_TEMP,M_NOWAIT); + if(!ep) return ENOMEM; + ep->next = fork_list; + ep->function = function; + fork_list = ep; + return 0; +} +/* + * Scan the exit callout list for the given items and remove them. + * Returns the number of items removed. + */ +int +rm_at_fork(forklist_fn function) +{ + fle_p *epp,ep; + int count = 0; + + epp = &fork_list; + ep = *epp; + while(ep) { + if(ep->function == function) { + *epp = ep->next; + free(ep,M_TEMP); + count++; + } else { + epp = &ep->next; + } + ep = *epp; + } + return count; +} + + |
