proc: switch auxv to use of __mem_open()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 26 insertions, 19 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index ac0df4dde823..528c1bb57bc3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -400,23 +400,6 @@ static const struct file_operations proc_pid_cmdline_ops = {
         .llseek = generic_file_llseek,
 };
 
-static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
-                         struct pid *pid, struct task_struct *task)
-{
-        struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
-        if (mm && !IS_ERR(mm)) {
-                unsigned int nwords = 0;
-                do {
-                        nwords += 2;
-                } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
-                seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0]));
-                mmput(mm);
-                return 0;
-        } else
-                return PTR_ERR(mm);
-}
-
-
 #ifdef CONFIG_KALLSYMS
 /*
  * Provides a wchan file via kallsyms in a proper one-value-per-file format.
@@ -1014,6 +997,30 @@ static const struct file_operations proc_environ_operations = {
         .release        = mem_release,
 };
 
+static int auxv_open(struct inode *inode, struct file *file)
+{
+        return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
+}
+
+static ssize_t auxv_read(struct file *file, char __user *buf,
+                        size_t count, loff_t *ppos)
+{
+        struct mm_struct *mm = file->private_data;
+        unsigned int nwords = 0;
+        do {
+                nwords += 2;
+        } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
+        return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
+                                       nwords * sizeof(mm->saved_auxv[0]));
+}
+
+static const struct file_operations proc_auxv_operations = {
+        .open           = auxv_open,
+        .read           = auxv_read,
+        .llseek         = generic_file_llseek,
+        .release        = mem_release,
+};
+
 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
                             loff_t *ppos)
 {
@@ -2822,7 +2829,7 @@ static const struct pid_entry tgid_base_stuff[] = {
         DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
 #endif
         REG("environ",    S_IRUSR, proc_environ_operations),
-        ONE("auxv",       S_IRUSR, proc_pid_auxv),
+        REG("auxv",       S_IRUSR, proc_auxv_operations),
         ONE("status",     S_IRUGO, proc_pid_status),
         ONE("personality", S_IRUSR, proc_pid_personality),
         ONE("limits",     S_IRUGO, proc_pid_limits),
@@ -3210,7 +3217,7 @@ static const struct pid_entry tid_base_stuff[] = {
         DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
 #endif
         REG("environ",   S_IRUSR, proc_environ_operations),
-        ONE("auxv",      S_IRUSR, proc_pid_auxv),
+        REG("auxv",      S_IRUSR, proc_auxv_operations),
         ONE("status",    S_IRUGO, proc_pid_status),
         ONE("personality", S_IRUSR, proc_pid_personality),
         ONE("limits",    S_IRUGO, proc_pid_limits),