patacongo commented on a change in pull request #3626: URL: https://github.com/apache/incubator-nuttx/pull/3626#discussion_r623136987
########## File path: libs/libc/pthread/pthread_exit.c ########## @@ -0,0 +1,72 @@ +/**************************************************************************** + * libs/libc/pthread/pthread_exit.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <debug.h> +#include <sched.h> + +#include <nuttx/pthread.h> + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: pthread_exit + * + * Description: + * Terminate execution of a thread started with pthread_create. + * + * Input Parameters: + * exit_valie + * + * Returned Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +void pthread_exit(FAR void *exit_value) +{ Review comment: pthread_exit() must only be called from user space, especially after this change. However, I still see several calls to pthread_exit(). In the original code before your change there are these: sched/pthread/pthread_create.c: pthread_exit(exit_status); sched/signal/sig_default.c: pthread_exit(NULL); sched/task/task_cancelpt.c: pthread_exit(PTHREAD_CANCELED); sched/task/task_cancelpt.c: pthread_exit(PTHREAD_CANCELED); sched/task/task_setcancelstate.c: pthread_exit(PTHREAD_CANCELED); sched/task/task_setcanceltype.c: pthread_exit(PTHREAD_CANCELED); I think this is an error. We must not call pthread_exit() from within the OS without first dropping the privileges to user. Otherwise, the problem that we are trying to solve with this PR is not solved. Possible solution: 1. Add a pointer to pthread_exit to nx_pthread_create(). We have to do this because the address of pthread_exit() will not be known in the PROTECTED and KERNEL builds. I think you were not seeing the build failure in the PROTECTED/KERNEL builds because cancellation points and default signal actions were not enabled. 2. Save the pthread_exit() pointer in the TCB 3. Replace calls to pthread_exit() in the OS to up_pthread_exit(). 4. up_pthread_exit should issue a trap that drops to user mode and calls to the saved pthread_exit() entry point. Hmm.. I think that the lm3s6965-ek:qemu-protected should have given an error: $ find boards/ -name defconfig | xargs grep -l BUILD_PROTECTED | xargs grep CANCELLATION $ find boards/ -name defconfig | xargs grep -l BUILD_PROTECTED | xargs grep SIG_DEFAULT boards/arm/tiva/lm3s6965-ek/configs/qemu-protected/defconfig:CONFIG_SIG_DEFAULT=y $ find boards/ -name defconfig | xargs grep -l BUILD_KERNEL | xargs grep CANCELLATION $ find boards/ -name defconfig | xargs grep -l BUILD_KERNEL | xargs grep SIG_DEFAULT It would be worth checking the System.map to assure that pthread_exit() is never referenced in the kernel blob. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
