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author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-09-03 16:22:32 +0200 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-09-08 22:20:39 -0400 |
commit | 4bd6a7353ee14697fea645e941354976d2c4a452 (patch) | |
tree | fc5477c5f8ff20e2b5e5d66ecc8c319ff44b4fd0 /fs/proc | |
parent | fd5a13f4893c8df2a5a3af8599adecb52d05fe89 (diff) | |
download | linux-4bd6a7353ee14697fea645e941354976d2c4a452.tar.gz linux-4bd6a7353ee14697fea645e941354976d2c4a452.tar.bz2 linux-4bd6a7353ee14697fea645e941354976d2c4a452.zip |
sysctl: Convert to iter interfaces
Using the read_iter/write_iter interfaces allows for in-kernel users
to set sysctls without using set_fs(). Also, the buffer is a string,
so give it the real type of 'char *', not void *.
[AV: Christoph's fixup folded in]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/proc')
-rw-r--r-- | fs/proc/proc_sysctl.c | 48 |
1 files changed, 24 insertions, 24 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 6c1166ccdaea..317899222d7f 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -12,6 +12,7 @@ #include <linux/cred.h> #include <linux/namei.h> #include <linux/mm.h> +#include <linux/uio.h> #include <linux/module.h> #include <linux/bpf-cgroup.h> #include <linux/mount.h> @@ -540,13 +541,14 @@ out: return err; } -static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf, - size_t count, loff_t *ppos, int write) +static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter, + int write) { - struct inode *inode = file_inode(filp); + struct inode *inode = file_inode(iocb->ki_filp); struct ctl_table_header *head = grab_header(inode); struct ctl_table *table = PROC_I(inode)->sysctl_entry; - void *kbuf; + size_t count = iov_iter_count(iter); + char *kbuf; ssize_t error; if (IS_ERR(head)) @@ -569,32 +571,30 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf, error = -ENOMEM; if (count >= KMALLOC_MAX_SIZE) goto out; + kbuf = kzalloc(count + 1, GFP_KERNEL); + if (!kbuf) + goto out; if (write) { - kbuf = memdup_user_nul(ubuf, count); - if (IS_ERR(kbuf)) { - error = PTR_ERR(kbuf); - goto out; - } - } else { - kbuf = kzalloc(count, GFP_KERNEL); - if (!kbuf) - goto out; + error = -EFAULT; + if (!copy_from_iter_full(kbuf, count, iter)) + goto out_free_buf; + kbuf[count] = '\0'; } error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count, - ppos); + &iocb->ki_pos); if (error) goto out_free_buf; /* careful: calling conventions are nasty here */ - error = table->proc_handler(table, write, kbuf, &count, ppos); + error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos); if (error) goto out_free_buf; if (!write) { error = -EFAULT; - if (copy_to_user(ubuf, kbuf, count)) + if (copy_to_iter(kbuf, count, iter) < count) goto out_free_buf; } @@ -607,16 +607,14 @@ out: return error; } -static ssize_t proc_sys_read(struct file *filp, char __user *buf, - size_t count, loff_t *ppos) +static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter) { - return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); + return proc_sys_call_handler(iocb, iter, 0); } -static ssize_t proc_sys_write(struct file *filp, const char __user *buf, - size_t count, loff_t *ppos) +static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter) { - return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); + return proc_sys_call_handler(iocb, iter, 1); } static int proc_sys_open(struct inode *inode, struct file *filp) @@ -853,8 +851,10 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat, static const struct file_operations proc_sys_file_operations = { .open = proc_sys_open, .poll = proc_sys_poll, - .read = proc_sys_read, - .write = proc_sys_write, + .read_iter = proc_sys_read, + .write_iter = proc_sys_write, + .splice_read = generic_file_splice_read, + .splice_write = iter_file_splice_write, .llseek = default_llseek, }; |