proc: clean up /proc/<pid>/environ handling
Similar to e268337dfe
("proc: clean up and fix /proc/<pid>/mem
handling"), move the check of permission to open(), this will simplify
read() code.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
168eeccbc9
commit
b409e578d9
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@ -679,7 +679,7 @@ static const struct file_operations proc_single_file_operations = {
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.release = single_release,
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.release = single_release,
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};
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};
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static int mem_open(struct inode* inode, struct file* file)
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static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
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{
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{
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struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
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struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
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struct mm_struct *mm;
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struct mm_struct *mm;
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@ -687,7 +687,7 @@ static int mem_open(struct inode* inode, struct file* file)
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if (!task)
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if (!task)
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return -ESRCH;
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return -ESRCH;
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mm = mm_access(task, PTRACE_MODE_ATTACH);
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mm = mm_access(task, mode);
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put_task_struct(task);
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put_task_struct(task);
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if (IS_ERR(mm))
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if (IS_ERR(mm))
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@ -707,6 +707,11 @@ static int mem_open(struct inode* inode, struct file* file)
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return 0;
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return 0;
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}
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}
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static int mem_open(struct inode *inode, struct file *file)
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{
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return __mem_open(inode, file, PTRACE_MODE_ATTACH);
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}
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static ssize_t mem_rw(struct file *file, char __user *buf,
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static ssize_t mem_rw(struct file *file, char __user *buf,
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size_t count, loff_t *ppos, int write)
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size_t count, loff_t *ppos, int write)
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{
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{
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@ -803,30 +808,29 @@ static const struct file_operations proc_mem_operations = {
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.release = mem_release,
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.release = mem_release,
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};
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};
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static int environ_open(struct inode *inode, struct file *file)
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{
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return __mem_open(inode, file, PTRACE_MODE_READ);
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}
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static ssize_t environ_read(struct file *file, char __user *buf,
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static ssize_t environ_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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size_t count, loff_t *ppos)
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{
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{
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struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
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char *page;
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char *page;
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unsigned long src = *ppos;
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unsigned long src = *ppos;
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int ret = -ESRCH;
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int ret = 0;
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struct mm_struct *mm;
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struct mm_struct *mm = file->private_data;
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if (!task)
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if (!mm)
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goto out_no_task;
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return 0;
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ret = -ENOMEM;
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page = (char *)__get_free_page(GFP_TEMPORARY);
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page = (char *)__get_free_page(GFP_TEMPORARY);
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if (!page)
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if (!page)
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goto out;
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return -ENOMEM;
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mm = mm_for_maps(task);
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ret = PTR_ERR(mm);
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if (!mm || IS_ERR(mm))
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goto out_free;
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ret = 0;
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ret = 0;
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if (!atomic_inc_not_zero(&mm->mm_users))
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goto free;
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while (count > 0) {
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while (count > 0) {
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int this_len, retval, max_len;
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int this_len, retval, max_len;
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@ -838,7 +842,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
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max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
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max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
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this_len = (this_len > max_len) ? max_len : this_len;
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this_len = (this_len > max_len) ? max_len : this_len;
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retval = access_process_vm(task, (mm->env_start + src),
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retval = access_remote_vm(mm, (mm->env_start + src),
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page, this_len, 0);
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page, this_len, 0);
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if (retval <= 0) {
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if (retval <= 0) {
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@ -857,19 +861,18 @@ static ssize_t environ_read(struct file *file, char __user *buf,
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count -= retval;
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count -= retval;
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}
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}
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*ppos = src;
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*ppos = src;
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mmput(mm);
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mmput(mm);
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out_free:
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free:
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free_page((unsigned long) page);
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free_page((unsigned long) page);
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out:
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put_task_struct(task);
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out_no_task:
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return ret;
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return ret;
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}
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}
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static const struct file_operations proc_environ_operations = {
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static const struct file_operations proc_environ_operations = {
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.open = environ_open,
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.read = environ_read,
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.read = environ_read,
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.llseek = generic_file_llseek,
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.llseek = generic_file_llseek,
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.release = mem_release,
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};
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};
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static ssize_t oom_adjust_read(struct file *file, char __user *buf,
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static ssize_t oom_adjust_read(struct file *file, char __user *buf,
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