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

commit 3f4c8211d982099be693be9aa7d6fc4607dff290 upstream.

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: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.816175235@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Zijlstra 2022-10-25 21:38:21 +02:00 committed by Greg Kroah-Hartman
parent ddcf05fe88
commit 3d1b8cfdd0
3 changed files with 2 additions and 7 deletions

View File

@ -7,6 +7,7 @@
#include <linux/swapops.h>
#include <linux/kmemleak.h>
#include <linux/sched/task.h>
#include <linux/sched/mm.h>
#include <asm/set_memory.h>
#include <asm/cpu_device_id.h>
@ -736,7 +737,7 @@ void __init poking_init(void)
spinlock_t *ptl;
pte_t *ptep;
poking_mm = copy_init_mm();
poking_mm = mm_alloc();
BUG_ON(!poking_mm);
/* Xen PV guests need the PGD to be pinned. */

View File

@ -93,7 +93,6 @@ extern long _do_fork(struct kernel_clone_args *kargs);
extern bool legacy_clone_args_valid(const 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);
extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);

View File

@ -2335,11 +2335,6 @@ struct task_struct *fork_idle(int cpu)
return task;
}
struct mm_struct *copy_init_mm(void)
{
return dup_mm(NULL, &init_mm);
}
/*
* Ok, this is the main fork-routine.
*