Commit d3f5ffca authored by John Hubbard's avatar John Hubbard Committed by Linus Torvalds
Browse files

mm: cleanup: remove unused tsk arg from __access_remote_vm 

Despite a comment that said that page fault accounting would be charged to
whatever task_struct* was passed into __access_remote_vm(), the tsk
argument was actually unused.

Making page fault accounting actually use this task struct is quite a
project, so there is no point in keeping the tsk argument.

Delete both the comment, and the argument.

[rppt@linux.ibm.com: changelog addition]

Link: https://lkml.kernel.org/r/20201026074137.4147787-1-jhubbard@nvidia.com


Signed-off-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent be37c98d

include/linux/mm.h

+2 −2
Original line number Diff line number Diff line
@@ -1716,8 +1716,8 @@ extern int access_process_vm(struct task_struct *tsk, unsigned long addr, 
		void *buf, int len, unsigned int gup_flags);

extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,

		void *buf, int len, unsigned int gup_flags);

extern int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,

		unsigned long addr, void *buf, int len, unsigned int gup_flags);

extern int __access_remote_vm(struct mm_struct *mm, unsigned long addr,

			      void *buf, int len, unsigned int gup_flags);



long get_user_pages_remote(struct mm_struct *mm,

			    unsigned long start, unsigned long nr_pages,

kernel/ptrace.c

+1 −1
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 
		return 0;

	}



	ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);

	ret = __access_remote_vm(mm, addr, buf, len, gup_flags);

	mmput(mm);



	return ret;

mm/memory.c

+5 −6
Original line number Diff line number Diff line
@@ -4885,11 +4885,10 @@ EXPORT_SYMBOL_GPL(generic_access_phys); 
#endif



/*

 * Access another process' address space as given in mm.  If non-NULL, use the

 * given task for page fault accounting.

 * Access another process' address space as given in mm.

 */

int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,

		unsigned long addr, void *buf, int len, unsigned int gup_flags)

int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf,

		       int len, unsigned int gup_flags)

{

	struct vm_area_struct *vma;

	void *old_buf = buf;
@@ -4966,7 +4965,7 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 
int access_remote_vm(struct mm_struct *mm, unsigned long addr,

		void *buf, int len, unsigned int gup_flags)

{

	return __access_remote_vm(NULL, mm, addr, buf, len, gup_flags);

	return __access_remote_vm(mm, addr, buf, len, gup_flags);

}



/*
@@ -4984,7 +4983,7 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, 
	if (!mm)

		return 0;



	ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);

	ret = __access_remote_vm(mm, addr, buf, len, gup_flags);



	mmput(mm);

mm/nommu.c

+4 −4
Original line number Diff line number Diff line
@@ -1675,8 +1675,8 @@ void filemap_map_pages(struct vm_fault *vmf, 
}

EXPORT_SYMBOL(filemap_map_pages);



int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,

		unsigned long addr, void *buf, int len, unsigned int gup_flags)

int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf,

		       int len, unsigned int gup_flags)

{

	struct vm_area_struct *vma;

	int write = gup_flags & FOLL_WRITE;
@@ -1722,7 +1722,7 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 
int access_remote_vm(struct mm_struct *mm, unsigned long addr,

		void *buf, int len, unsigned int gup_flags)

{

	return __access_remote_vm(NULL, mm, addr, buf, len, gup_flags);

	return __access_remote_vm(mm, addr, buf, len, gup_flags);

}



/*
@@ -1741,7 +1741,7 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in 
	if (!mm)

		return 0;



	len = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);

	len = __access_remote_vm(mm, addr, buf, len, gup_flags);



	mmput(mm);

	return len;