Commit 3f4c8211 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Dave Hansen
Browse files

x86/mm: Use mm_alloc() in poking_init() 



Instead of duplicating init_mm, allocate a fresh mm. The advantage is
that mm_alloc() has much simpler dependencies. Additionally it makes
more conceptual sense, init_mm has no (and must not have) user state
to duplicate.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.816175235@infradead.org
parent af806027

arch/x86/mm/init.c

+1 −1
Original line number Diff line number Diff line
@@ -801,7 +801,7 @@ void __init poking_init(void) 
	spinlock_t *ptl;

	pte_t *ptep;



	poking_mm = copy_init_mm();

	poking_mm = mm_alloc();

	BUG_ON(!poking_mm);



	/*

include/linux/sched/task.h

+0 −1
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ extern void exit_itimers(struct task_struct *); 
extern pid_t kernel_clone(struct kernel_clone_args *kargs);

struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);

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);

extern pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags);

extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);

kernel/fork.c

+0 −5
Original line number Diff line number Diff line
@@ -2592,11 +2592,6 @@ struct task_struct * __init fork_idle(int cpu) 
	return task;

}



struct mm_struct *copy_init_mm(void)

{

	return dup_mm(NULL, &init_mm);

}



/*

 * This is like kernel_clone(), but shaved down and tailored to just

 * creating io_uring workers. It returns a created task, or an error pointer.