[PATCH 2/7] pipe, sysctl: remove pipe_proc_fn()

Eric Biggers
2018-01-08T05:38:59Z

From: Eric Biggers <ebiggers@google.com>

pipe_proc_fn() is no longer needed, as it only calls through to
proc_dopipe_max_size(). Just put proc_dopipe_max_size() in the
ctl_table entry directly, and remove the unneeded EXPORT_SYMBOL() and
the ENOSYS stub for it.

(The reason the ENOSYS stub isn't needed is that the pipe-max-size
ctl_table entry is located directly in 'kern_table' rather than being
registered separately. Therefore, the entry is already only defined
when the kernel is built with sysctl support.)

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
fs/pipe.c | 10 ----------
include/linux/pipe_fs_i.h | 1 -
include/linux/sysctl.h | 3 ---
kernel/sysctl.c | 15 +++++----------
4 files changed, 5 insertions(+), 24 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index a75f5d2ca99c..d0dec5e7ef33 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1120,16 +1120,6 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
return ret;
}

-/*
- * This should work even if CONFIG_PROC_FS isn't set, as proc_dopipe_max_size
- * will return an error.
- */
-int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
- size_t *lenp, loff_t *ppos)
-{
- return proc_dopipe_max_size(table, write, buf, lenp, ppos);
-}
-
/*
* After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same
* location, so checking ->i_pipe is not enough to verify that this is a
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 7d9beda14584..5028bd4b2c96 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -170,7 +170,6 @@ void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
extern unsigned int pipe_max_size;
extern unsigned long pipe_user_pages_hard;
extern unsigned long pipe_user_pages_soft;
-int pipe_proc_fn(struct ctl_table *, int, void __user *, size_t *, loff_t *);

/* Drop the inode semaphore and wait for a pipe event, atomically */
void pipe_wait(struct pipe_inode_info *pipe);
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 992bc9948232..b769ecfcc3bd 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -51,9 +51,6 @@ extern int proc_dointvec_minmax(struct ctl_table *, int,
extern int proc_douintvec_minmax(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
-extern int proc_dopipe_max_size(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
extern int proc_dointvec_jiffies(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index a71ebb5c5182..33e2f0f02000 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -218,6 +218,8 @@ static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
static int proc_dostring_coredump(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif
+static int proc_dopipe_max_size(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos);

#ifdef CONFIG_MAGIC_SYSRQ
/* Note: sysrq code uses it's own private copy */
@@ -1819,7 +1821,7 @@ static struct ctl_table fs_table[] = {
.data = &pipe_max_size,
.maxlen = sizeof(pipe_max_size),
.mode = 0644,
- .proc_handler = &pipe_proc_fn,
+ .proc_handler = proc_dopipe_max_size,
},
{
.procname = "pipe-user-pages-hard",
@@ -2644,8 +2646,8 @@ static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
return 0;
}

-int proc_dopipe_max_size(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp, loff_t *ppos)
+static int proc_dopipe_max_size(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
{
return do_proc_douintvec(table, write, buffer, lenp, ppos,
do_proc_dopipe_max_size_conv, NULL);
@@ -3154,12 +3156,6 @@ int proc_douintvec_minmax(struct ctl_table *table, int write,
return -ENOSYS;
}

-int proc_dopipe_max_size(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp, loff_t *ppos)
-{
- return -ENOSYS;
-}
-
int proc_dointvec_jiffies(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
@@ -3203,7 +3199,6 @@ EXPORT_SYMBOL(proc_douintvec);
EXPORT_SYMBOL(proc_dointvec_jiffies);
EXPORT_SYMBOL(proc_dointvec_minmax);
EXPORT_SYMBOL_GPL(proc_douintvec_minmax);
-EXPORT_SYMBOL_GPL(proc_dopipe_max_size);
EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
EXPORT_SYMBOL(proc_dostring);
--
2.15.1