[PATCH] mm: cleanup: remove unused tsk arg from __access_remote_vm

From: John Hubbard
Date: Mon Oct 26 2020 - 03:41:40 EST


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.

Delete both the comment, and the argument.

Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
---

Hi,

Just something that caught my eye when I was reviewing a semi-related
patchset.

thanks,
John Hubbard
NVIDIA

include/linux/mm.h | 4 ++--
kernel/ptrace.c | 2 +-
mm/memory.c | 11 +++++------
mm/nommu.c | 8 ++++----
4 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index ef360fe70aaf..b3b85a5c5937 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 43d6179508d6..fbbe32443b18 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 c48f8df6e502..25b28bc251d5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4874,11 +4874,10 @@ 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;
@@ -4955,7 +4954,7 @@ 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);
}

/*
@@ -4973,7 +4972,7 @@ 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;

base-commit: 3650b228f83adda7e5ee532e2b90429c03f7b9ec
--
2.29.0