From: Minchan Kim <minchan@kernel.org> To: Andrew Morton <akpm@linux-foundation.org> Cc: LKML <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>, linux-api@vger.kernel.org, oleksandr@redhat.com, Suren Baghdasaryan <surenb@google.com>, Tim Murray <timmurray@google.com>, Daniel Colascione <dancol@google.com>, Sandeep Patil <sspatil@google.com>, Sonny Rao <sonnyrao@google.com>, Brian Geffon <bgeffon@google.com>, Michal Hocko <mhocko@suse.com>, Johannes Weiner <hannes@cmpxchg.org>, Shakeel Butt <shakeelb@google.com>, John Dias <joaodias@google.com>, Joel Fernandes <joel@joelfernandes.org>, Jann Horn <jannh@google.com>, alexander.h.duyck@linux.intel.com, sj38.park@gmail.com, Minchan Kim <minchan@kernel.org>, Jens Axboe <axboe@kernel.dk> Subject: [PATCH v7 1/7] mm: pass task and mm to do_madvise Date: Mon, 2 Mar 2020 11:36:24 -0800 [thread overview] Message-ID: <20200302193630.68771-2-minchan@kernel.org> (raw) In-Reply-To: <20200302193630.68771-1-minchan@kernel.org> In upcoming patches, do_madvise will be called from external process context so we shouldn't asssume "current" is always hinted process's task_struct. Furthermore, we couldn't access mm_struct via task->mm once it's verified by access_mm which will be introduced in next patch[1]. And let's pass *current* and current->mm as arguments of do_madvise so it shouldn't change existing behavior but prepare next patch to make review easy. Note: io_madvise pass NULL as target_task argument of do_madvise because it couldn't know who is target. [1] http://lore.kernel.org/r/CAG48ez27=pwm5m_N_988xT1huO7g7h6arTQL44zev6TD-h-7Tg@mail.gmail.com Cc: Jens Axboe <axboe@kernel.dk> Cc: Jann Horn <jannh@google.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Minchan Kim <minchan@kernel.org> --- fs/io_uring.c | 2 +- include/linux/mm.h | 3 ++- mm/madvise.c | 34 +++++++++++++++++++--------------- 3 files changed, 22 insertions(+), 17 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 8866bd60783f..8b53f150560e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2736,7 +2736,7 @@ static int io_madvise(struct io_kiocb *req, struct io_kiocb **nxt, if (force_nonblock) return -EAGAIN; - ret = do_madvise(ma->addr, ma->len, ma->advice); + ret = do_madvise(NULL, req->work.mm, ma->addr, ma->len, ma->advice); if (ret < 0) req_set_fail_links(req); io_cqring_add_event(req, ret); diff --git a/include/linux/mm.h b/include/linux/mm.h index c1180112102d..378de56d8c5b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2407,7 +2407,8 @@ extern int __do_munmap(struct mm_struct *, unsigned long, size_t, struct list_head *uf, bool downgrade); extern int do_munmap(struct mm_struct *, unsigned long, size_t, struct list_head *uf); -extern int do_madvise(unsigned long start, size_t len_in, int behavior); +extern int do_madvise(struct task_struct *target_task, struct mm_struct *mm, + unsigned long start, size_t len_in, int behavior); static inline unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, diff --git a/mm/madvise.c b/mm/madvise.c index 43b47d3fae02..f75c86b6c463 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -254,6 +254,7 @@ static long madvise_willneed(struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start, unsigned long end) { + struct mm_struct *mm = vma->vm_mm; struct file *file = vma->vm_file; loff_t offset; @@ -288,12 +289,12 @@ static long madvise_willneed(struct vm_area_struct *vma, */ *prev = NULL; /* tell sys_madvise we drop mmap_sem */ get_file(file); - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); offset = (loff_t)(start - vma->vm_start) + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); fput(file); - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); return 0; } @@ -676,7 +677,6 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, if (nr_swap) { if (current->mm == mm) sync_mm_rss(mm); - add_mm_counter(mm, MM_SWAPENTS, nr_swap); } arch_leave_lazy_mmu_mode(); @@ -756,6 +756,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma, unsigned long start, unsigned long end, int behavior) { + struct mm_struct *mm = vma->vm_mm; + *prev = vma; if (!can_madv_lru_vma(vma)) return -EINVAL; @@ -763,8 +765,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma, if (!userfaultfd_remove(vma, start, end)) { *prev = NULL; /* mmap_sem has been dropped, prev is stale */ - down_read(¤t->mm->mmap_sem); - vma = find_vma(current->mm, start); + down_read(&mm->mmap_sem); + vma = find_vma(mm, start); if (!vma) return -ENOMEM; if (start < vma->vm_start) { @@ -818,6 +820,7 @@ static long madvise_remove(struct vm_area_struct *vma, loff_t offset; int error; struct file *f; + struct mm_struct *mm = vma->vm_mm; *prev = NULL; /* tell sys_madvise we drop mmap_sem */ @@ -845,13 +848,13 @@ static long madvise_remove(struct vm_area_struct *vma, get_file(f); if (userfaultfd_remove(vma, start, end)) { /* mmap_sem was not released by userfaultfd_remove() */ - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); } error = vfs_fallocate(f, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, end - start); fput(f); - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); return error; } @@ -1044,7 +1047,8 @@ madvise_behavior_valid(int behavior) * -EBADF - map exists, but area maps something that isn't a file. * -EAGAIN - a kernel resource was temporarily unavailable. */ -int do_madvise(unsigned long start, size_t len_in, int behavior) +int do_madvise(struct task_struct *target_task, struct mm_struct *mm, + unsigned long start, size_t len_in, int behavior) { unsigned long end, tmp; struct vm_area_struct *vma, *prev; @@ -1082,10 +1086,10 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) write = madvise_need_mmap_write(behavior); if (write) { - if (down_write_killable(¤t->mm->mmap_sem)) + if (down_write_killable(&mm->mmap_sem)) return -EINTR; } else { - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); } /* @@ -1093,7 +1097,7 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) * ranges, just ignore them, but return -ENOMEM at the end. * - different from the way of handling in mlock etc. */ - vma = find_vma_prev(current->mm, start, &prev); + vma = find_vma_prev(mm, start, &prev); if (vma && start > vma->vm_start) prev = vma; @@ -1130,19 +1134,19 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) if (prev) vma = prev->vm_next; else /* madvise_remove dropped mmap_sem */ - vma = find_vma(current->mm, start); + vma = find_vma(mm, start); } out: blk_finish_plug(&plug); if (write) - up_write(¤t->mm->mmap_sem); + up_write(&mm->mmap_sem); else - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); return error; } SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) { - return do_madvise(start, len_in, behavior); + return do_madvise(current, current->mm, start, len_in, behavior); } -- 2.25.0.265.gbab2e86ba0-goog
next prev parent reply other threads:[~2020-03-02 19:36 UTC|newest] Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-02 19:36 [PATCH v7 0/7] introduce memory hinting API for external process Minchan Kim 2020-03-02 19:36 ` Minchan Kim [this message] 2020-03-05 15:48 ` [PATCH v7 1/7] mm: pass task and mm to do_madvise Vlastimil Babka 2020-05-08 18:21 ` Minchan Kim 2020-03-02 19:36 ` [PATCH v7 2/7] mm: introduce external memory hinting API Minchan Kim 2020-03-03 10:33 ` kbuild test robot 2020-03-03 14:57 ` Minchan Kim 2020-03-05 18:15 ` Vlastimil Babka 2020-03-10 22:20 ` Minchan Kim 2020-03-11 0:36 ` Minchan Kim 2020-03-12 12:40 ` Vlastimil Babka 2020-03-12 20:23 ` Minchan Kim 2020-05-08 18:33 ` Minchan Kim 2020-03-02 19:36 ` [PATCH v7 3/7] mm: check fatal signal pending of target process Minchan Kim 2020-03-06 10:22 ` Vlastimil Babka 2020-03-10 22:24 ` Minchan Kim 2020-03-02 19:36 ` [PATCH v7 4/7] pid: move pidfd_get_pid function to pid.c Minchan Kim 2020-03-06 10:57 ` Vlastimil Babka 2020-03-06 11:14 ` Christian Brauner 2020-03-02 19:36 ` [PATCH v7 5/7] mm: support both pid and pidfd for process_madvise Minchan Kim 2020-03-06 11:14 ` Vlastimil Babka 2020-03-11 0:42 ` Minchan Kim 2020-05-08 18:36 ` Minchan Kim 2020-05-08 23:04 ` Andrew Morton 2020-05-09 12:48 ` Christian Brauner 2020-05-09 23:14 ` Minchan Kim 2020-05-12 19:55 ` Suren Baghdasaryan 2020-03-02 19:36 ` [PATCH v7 6/7] mm/madvise: employ mmget_still_valid for write lock Minchan Kim 2020-03-06 12:52 ` Vlastimil Babka 2020-03-06 13:03 ` Oleksandr Natalenko 2020-03-06 16:03 ` Vlastimil Babka 2020-03-09 12:30 ` Oleksandr Natalenko 2020-03-10 22:28 ` Minchan Kim 2020-03-02 19:36 ` [PATCH v7 7/7] mm/madvise: allow KSM hints for remote API Minchan Kim 2020-03-06 13:13 ` Vlastimil Babka 2020-03-06 13:41 ` Oleksandr Natalenko 2020-03-06 16:08 ` Vlastimil Babka 2020-03-09 13:11 ` Oleksandr Natalenko 2020-03-09 15:08 ` Michal Hocko 2020-03-09 15:19 ` Oleksandr Natalenko 2020-03-09 15:42 ` Vlastimil Babka 2020-03-09 16:03 ` Michal Hocko 2020-06-11 2:21 ` Jann Horn 2020-03-02 21:16 ` [PATCH v7 0/7] introduce memory hinting API for external process Andrew Morton 2020-03-02 21:42 ` Minchan Kim
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