From: John Hubbard <jhubbard@xxxxxxxxxx> Subject: 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@xxxxxxxxxxxxx: changelog addition] Link: https://lkml.kernel.org/r/20201026074137.4147787-1-jhubbard@xxxxxxxxxx Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 4 ++-- kernel/ptrace.c | 2 +- mm/memory.c | 11 +++++------ mm/nommu.c | 8 ++++---- 4 files changed, 12 insertions(+), 13 deletions(-) --- a/include/linux/mm.h~mm-cleanup-remove-unused-tsk-arg-from-__access_remote_vm +++ a/include/linux/mm.h @@ -1716,8 +1716,8 @@ extern int access_process_vm(struct task 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, --- a/kernel/ptrace.c~mm-cleanup-remove-unused-tsk-arg-from-__access_remote_vm +++ a/kernel/ptrace.c @@ -57,7 +57,7 @@ int ptrace_access_vm(struct task_struct 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; --- a/mm/memory.c~mm-cleanup-remove-unused-tsk-arg-from-__access_remote_vm +++ a/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_struc 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 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); --- a/mm/nommu.c~mm-cleanup-remove-unused-tsk-arg-from-__access_remote_vm +++ a/mm/nommu.c @@ -1675,8 +1675,8 @@ void filemap_map_pages(struct vm_fault * } 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_struc 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 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; _