The patch titled
Subject: proc: clean up /proc/<pid>/environ handling
has been added to the -mm tree. Its filename is
proc-clean-up-proc-pid-environ-handling.patch
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------------------------------------------------------
From: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Subject: proc: clean up /proc/<pid>/environ handling
Similar to e268337dfe2 ("proc: clean up and fix /proc/<pid>/mem
handling"), move the check of permission to open(), this will simplify
read() code.
Signed-off-by: WANG Cong <xiyou.wangcong@xxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/base.c | 55 +++++++++++++++++++++++++++++------------------
1 file changed, 35 insertions(+), 20 deletions(-)
diff -puN fs/proc/base.c~proc-clean-up-proc-pid-environ-handling fs/proc/base.c
--- a/fs/proc/base.c~proc-clean-up-proc-pid-environ-handling
+++ a/fs/proc/base.c
@@ -835,28 +835,38 @@ static const struct file_operations proc
.release = mem_release,
};
+static int environ_open(struct inode *inode, struct file *file)
+{
+ struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
+ struct mm_struct *mm;
+
+ if (!task)
+ return -ESRCH;
+
+ mm = mm_for_maps(task);
+ put_task_struct(task);
+
+ if (!mm)
+ return -ENOENT;
+ if (IS_ERR(mm))
+ return PTR_ERR(mm);
+
+ file->private_data = mm;
+
+ return 0;
+}
+
static ssize_t environ_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
char *page;
unsigned long src = *ppos;
- int ret = -ESRCH;
- struct mm_struct *mm;
+ int ret = 0;
+ struct mm_struct *mm = file->private_data;
- if (!task)
- goto out_no_task;
-
- ret = -ENOMEM;
page = (char *)__get_free_page(GFP_TEMPORARY);
if (!page)
- goto out;
-
-
- mm = mm_for_maps(task);
- ret = PTR_ERR(mm);
- if (!mm || IS_ERR(mm))
- goto out_free;
+ return -ENOMEM;
ret = 0;
while (count > 0) {
@@ -870,7 +880,7 @@ static ssize_t environ_read(struct file
max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
this_len = (this_len > max_len) ? max_len : this_len;
- retval = access_process_vm(task, (mm->env_start + src),
+ retval = access_remote_vm(mm, (mm->env_start + src),
page, this_len, 0);
if (retval <= 0) {
@@ -890,18 +900,23 @@ static ssize_t environ_read(struct file
}
*ppos = src;
- mmput(mm);
-out_free:
free_page((unsigned long) page);
-out:
- put_task_struct(task);
-out_no_task:
return ret;
}
+static int environ_release(struct inode *inode, struct file *file)
+{
+ struct mm_struct *mm = file->private_data;
+
+ mmput(mm);
+ return 0;
+}
+
static const struct file_operations proc_environ_operations = {
+ .open = environ_open,
.read = environ_read,
.llseek = generic_file_llseek,
+ .release = environ_release,
};
static ssize_t oom_adjust_read(struct file *file, char __user *buf,
_
Subject: Subject: proc: clean up /proc/<pid>/environ handling
Patches currently in -mm which might be from xiyou.wangcong@xxxxxxxxx are
origin.patch
linux-next.patch
lkdtm-avoid-calling-lkdtm_do_action-with-spin-lock-held.patch
x86-mm-fix-the-size-calculation-of-mapping-tables.patch
kcore-make-get_sparsemem_vmemmap_info-static.patch
proc-clean-up-proc-pid-environ-handling.patch
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