seq_file private data carries the inode pointer here. Replace `struct inode *inode = m->private;` with: `struct inode *inode = file_inode(m->file);` to avoid the reliance on private data. This is needed so that `proc_single_show()` can be used by custom fops that utilize seq_file private data for other things. This is used in the next patch. The private data argument of corresponding single_open() calls is NULLified. Note that timens_offsets_show() already had `file_inode(m->file)` so the NULLification in `timens_offsets_open()` is unpaired. Signed-off-by: Stas Sergeev <stsp2@xxxxxxxxx> CC: Eric Biederman <ebiederm@xxxxxxxxxxxx> CC: Andy Lutomirski <luto@xxxxxxxxxx> CC: Aleksa Sarai <cyphar@xxxxxxxxxx> CC: Christian Brauner <brauner@xxxxxxxxxx> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CC: Jeff Layton <jlayton@xxxxxxxxxx> CC: Kees Cook <kees@xxxxxxxxxx> CC: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx> CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx> CC: Felix Moessbauer <felix.moessbauer@xxxxxxxxxxx> CC: Adrian Ratiu <adrian.ratiu@xxxxxxxxxxxxx> CC: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> CC: linux-kernel@xxxxxxxxxxxxxxx CC: linux-fsdevel@xxxxxxxxxxxxxxx CC: Jan Kara <jack@xxxxxxx> CC: Chengming Zhou <chengming.zhou@xxxxxxxxx> CC: Jens Axboe <axboe@xxxxxxxxx> CC: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx> --- fs/proc/base.c | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index b31283d81c52..e7c8554ec95a 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -528,7 +528,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, static int lstats_show_proc(struct seq_file *m, void *v) { int i; - struct inode *inode = m->private; + struct inode *inode = file_inode(m->file); struct task_struct *task = get_proc_task(inode); if (!task) @@ -557,7 +557,7 @@ static int lstats_show_proc(struct seq_file *m, void *v) static int lstats_open(struct inode *inode, struct file *file) { - return single_open(file, lstats_show_proc, inode); + return single_open(file, lstats_show_proc, NULL); } static ssize_t lstats_write(struct file *file, const char __user *buf, @@ -800,7 +800,7 @@ static const struct inode_operations proc_def_inode_operations = { static int proc_single_show(struct seq_file *m, void *v) { - struct inode *inode = m->private; + struct inode *inode = file_inode(m->file); struct pid_namespace *ns = proc_pid_ns(inode->i_sb); struct pid *pid = proc_pid(inode); struct task_struct *task; @@ -818,7 +818,7 @@ static int proc_single_show(struct seq_file *m, void *v) static int proc_single_open(struct inode *inode, struct file *filp) { - return single_open(filp, proc_single_show, inode); + return single_open(filp, proc_single_show, NULL); } static const struct file_operations proc_single_file_operations = { @@ -1494,7 +1494,7 @@ static const struct file_operations proc_fail_nth_operations = { */ static int sched_show(struct seq_file *m, void *v) { - struct inode *inode = m->private; + struct inode *inode = file_inode(m->file); struct pid_namespace *ns = proc_pid_ns(inode->i_sb); struct task_struct *p; @@ -1527,7 +1527,7 @@ sched_write(struct file *file, const char __user *buf, static int sched_open(struct inode *inode, struct file *filp) { - return single_open(filp, sched_show, inode); + return single_open(filp, sched_show, NULL); } static const struct file_operations proc_pid_sched_operations = { @@ -1546,7 +1546,7 @@ static const struct file_operations proc_pid_sched_operations = { */ static int sched_autogroup_show(struct seq_file *m, void *v) { - struct inode *inode = m->private; + struct inode *inode = file_inode(m->file); struct task_struct *p; p = get_proc_task(inode); @@ -1593,15 +1593,7 @@ sched_autogroup_write(struct file *file, const char __user *buf, static int sched_autogroup_open(struct inode *inode, struct file *filp) { - int ret; - - ret = single_open(filp, sched_autogroup_show, NULL); - if (!ret) { - struct seq_file *m = filp->private_data; - - m->private = inode; - } - return ret; + return single_open(filp, sched_autogroup_show, NULL); } static const struct file_operations proc_pid_sched_autogroup_operations = { @@ -1704,7 +1696,7 @@ static ssize_t timens_offsets_write(struct file *file, const char __user *buf, static int timens_offsets_open(struct inode *inode, struct file *filp) { - return single_open(filp, timens_offsets_show, inode); + return single_open(filp, timens_offsets_show, NULL); } static const struct file_operations proc_timens_offsets_operations = { @@ -1745,7 +1737,7 @@ static ssize_t comm_write(struct file *file, const char __user *buf, static int comm_show(struct seq_file *m, void *v) { - struct inode *inode = m->private; + struct inode *inode = file_inode(m->file); struct task_struct *p; p = get_proc_task(inode); @@ -1762,7 +1754,7 @@ static int comm_show(struct seq_file *m, void *v) static int comm_open(struct inode *inode, struct file *filp) { - return single_open(filp, comm_show, inode); + return single_open(filp, comm_show, NULL); } static const struct file_operations proc_pid_set_comm_operations = { @@ -2641,7 +2633,7 @@ static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, static int timerslack_ns_show(struct seq_file *m, void *v) { - struct inode *inode = m->private; + struct inode *inode = file_inode(m->file); struct task_struct *p; int err = 0; @@ -2675,7 +2667,7 @@ static int timerslack_ns_show(struct seq_file *m, void *v) static int timerslack_ns_open(struct inode *inode, struct file *filp) { - return single_open(filp, timerslack_ns_show, inode); + return single_open(filp, timerslack_ns_show, NULL); } static const struct file_operations proc_pid_set_timerslack_ns_operations = { -- 2.47.0