From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Cc: Cyrill Gorcunov <gorcunov@gmail.com>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH 5/5] proc: use down_read_killable for /proc/pid/map_files
Date: Wed, 15 May 2019 11:41:23 +0300 [thread overview]
Message-ID: <155790968346.1319.5754627575519802426.stgit@buzz> (raw)
In-Reply-To: <155790967258.1319.11531787078240675602.stgit@buzz>
It seems ->d_revalidate() could return any error (except ECHILD) to
abort validation and pass error as result of lookup sequence.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
fs/proc/base.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9c8ca6cd3ce4..515ab29c2adf 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1962,9 +1962,12 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
goto out;
if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
- down_read(&mm->mmap_sem);
- exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
- up_read(&mm->mmap_sem);
+ status = down_read_killable(&mm->mmap_sem);
+ if (!status) {
+ exact_vma_exists = !!find_exact_vma(mm, vm_start,
+ vm_end);
+ up_read(&mm->mmap_sem);
+ }
}
mmput(mm);
@@ -2010,8 +2013,11 @@ static int map_files_get_link(struct dentry *dentry, struct path *path)
if (rc)
goto out_mmput;
+ rc = down_read_killable(&mm->mmap_sem);
+ if (rc)
+ goto out_mmput;
+
rc = -ENOENT;
- down_read(&mm->mmap_sem);
vma = find_exact_vma(mm, vm_start, vm_end);
if (vma && vma->vm_file) {
*path = vma->vm_file->f_path;
@@ -2107,7 +2113,10 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
if (!mm)
goto out_put_task;
- down_read(&mm->mmap_sem);
+ result = ERR_PTR(-EINTR);
+ if (down_read_killable(&mm->mmap_sem))
+ goto out_put_mm;
+
vma = find_exact_vma(mm, vm_start, vm_end);
if (!vma)
goto out_no_vma;
@@ -2118,6 +2127,7 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
out_no_vma:
up_read(&mm->mmap_sem);
+out_put_mm:
mmput(mm);
out_put_task:
put_task_struct(task);
@@ -2160,7 +2170,12 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
mm = get_task_mm(task);
if (!mm)
goto out_put_task;
- down_read(&mm->mmap_sem);
+
+ ret = down_read_killable(&mm->mmap_sem);
+ if (ret) {
+ mmput(mm);
+ goto out_put_task;
+ }
nr_files = 0;
next prev parent reply other threads:[~2019-05-15 8:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 8:41 [PATCH 1/5] proc: use down_read_killable for /proc/pid/maps Konstantin Khlebnikov
2019-05-15 8:41 ` [PATCH 2/5] proc: use down_read_killable for /proc/pid/smaps_rollup Konstantin Khlebnikov
2019-05-17 12:45 ` Michal Hocko
2019-06-09 9:07 ` Konstantin Khlebnikov
2019-06-10 18:58 ` Michal Hocko
2019-05-15 8:41 ` [PATCH 3/5] proc: use down_read_killable for /proc/pid/pagemap Konstantin Khlebnikov
2019-05-17 12:46 ` Michal Hocko
2019-05-15 8:41 ` [PATCH 4/5] proc: use down_read_killable for /proc/pid/clear_refs Konstantin Khlebnikov
2019-05-17 12:47 ` Michal Hocko
2019-05-15 8:41 ` Konstantin Khlebnikov [this message]
2019-05-15 17:00 ` [PATCH 5/5] proc: use down_read_killable for /proc/pid/map_files Roman Gushchin
2019-05-15 9:05 ` [PATCH 1/5] proc: use down_read_killable for /proc/pid/maps Cyrill Gorcunov
2019-05-15 9:16 ` Kirill Tkhai
2019-05-17 12:41 ` Michal Hocko
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