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: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 12 insertions, 13 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5bbbf4aeee94..1d8e84bf718a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -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,
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 79de1294f8eb..a77d25c641e9 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -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;
diff --git a/mm/memory.c b/mm/memory.c
index 50632c4366b8..4a42a74a2240 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -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);
 
diff --git a/mm/nommu.c b/mm/nommu.c
index 0faf39b32cdb..870fea12823e 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -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;