From ff2a91127b374c75ae024b31d22f23ad49d16eb4 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Sun, 24 May 2020 20:57:00 +0200 Subject: [PATCH] fork: remove do_fork() Now that all architectures have been switched to use _do_fork() and the new struct kernel_clone_args calling convention we can remove the legacy do_fork() helper completely. The calling convention used to be brittle and do_fork() didn't buy us anything. The only calling convention accepted should be based on struct kernel_clone_args going forward. It's cleaner and uniform. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Al Viro Cc: "Matthew Wilcox (Oracle)" Cc: "Peter Zijlstra (Intel)" Signed-off-by: Christian Brauner --- include/linux/sched/task.h | 1 - kernel/fork.c | 25 +------------------------ 2 files changed, 1 insertion(+), 25 deletions(-) diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index ddce0ea..9f03c44 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -96,7 +96,6 @@ extern void exit_files(struct task_struct *); extern void exit_itimers(struct signal_struct *); extern long _do_fork(struct kernel_clone_args *kargs); -extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *); struct task_struct *fork_idle(int); struct mm_struct *copy_init_mm(void); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); diff --git a/kernel/fork.c b/kernel/fork.c index 9875aeb..0fd7eb1 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2493,29 +2493,6 @@ long _do_fork(struct kernel_clone_args *args) return nr; } -#ifndef CONFIG_HAVE_COPY_THREAD_TLS -/* For compatibility with architectures that call do_fork directly rather than - * using the syscall entry points below. */ -long do_fork(unsigned long clone_flags, - unsigned long stack_start, - unsigned long stack_size, - int __user *parent_tidptr, - int __user *child_tidptr) -{ - struct kernel_clone_args args = { - .flags = (lower_32_bits(clone_flags) & ~CSIGNAL), - .pidfd = parent_tidptr, - .child_tid = child_tidptr, - .parent_tid = parent_tidptr, - .exit_signal = (lower_32_bits(clone_flags) & CSIGNAL), - .stack = stack_start, - .stack_size = stack_size, - }; - - return _do_fork(&args); -} -#endif - /* * Create a kernel thread. */ @@ -2923,7 +2900,7 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp /* * unshare allows a process to 'unshare' part of the process * context which was originally shared using clone. copy_* - * functions used by do_fork() cannot be used here directly + * functions used by _do_fork() cannot be used here directly * because they modify an inactive task_struct that is being * constructed. Here we are modifying the current, active, * task_struct. -- 2.7.4