From 2c1cccc529737527ad9ef981952d2c14d3dd13ec Mon Sep 17 00:00:00 2001 From: Flávio Cruz Date: Fri, 28 Aug 2015 01:34:01 +0200 Subject: Make sure the reply port's reference is released when the thread needs to be halted. * kern/thread.h (thread_halt_self): Add continuation_t parameter. * kern/thread.c (thread_halt_self): Pass continuation_t parameter to thread_block instead of thread_exception_return. * kern/ast.c (ast_taken): Pass thread_exception_return to thread_halt_self. * kern/profile.c (profile_thread): Likewise. * kern/exception.c (exception_no_server): Likewise. (thread_release_and_exception_return): New function. (exception_raise_continue_slow): Pass thread_release_and_exception_return to thread_halt_self. --- kern/exception.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) (limited to 'kern/exception.c') diff --git a/kern/exception.c b/kern/exception.c index 6cb3bfbf..63a63d66 100644 --- a/kern/exception.c +++ b/kern/exception.c @@ -231,7 +231,7 @@ exception_no_server(void) */ while (thread_should_halt(self)) - thread_halt_self(); + thread_halt_self(thread_exception_return); #if 0 @@ -257,7 +257,7 @@ exception_no_server(void) */ (void) task_terminate(self->task); - thread_halt_self(); + thread_halt_self(thread_exception_return); panic("terminating the task didn't kill us"); /*NOTREACHED*/ } @@ -847,6 +847,26 @@ exception_raise_continue(void) /*NOTREACHED*/ } +/* + * Routine: thread_release_and_exception_return + * Purpose: + * Continue after thread was halted. + * Conditions: + * Nothing locked. We are running on a new kernel stack and + * control goes back to thread_exception_return. + * Returns: + * Doesn't return. + */ +static void +thread_release_and_exception_return(void) +{ + ipc_thread_t self = current_thread(); + /* reply port must be released */ + ipc_port_release(self->ith_port); + thread_exception_return(); + /*NOTREACHED*/ +} + /* * Routine: exception_raise_continue_slow * Purpose: @@ -876,10 +896,14 @@ exception_raise_continue_slow( */ while (thread_should_halt(self)) { - /* don't terminate while holding a reference */ + /* if thread is about to terminate, release the port */ if (self->ast & AST_TERMINATE) ipc_port_release(reply_port); - thread_halt_self(); + /* + * Use the continuation to release the port in + * case the thread is about to halt. + */ + thread_halt_self(thread_release_and_exception_return); } ip_lock(reply_port); -- cgit v1.2.3