From 774636e19ed514cdf560006813c0473409616de8 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 9 Sep 2015 15:36:59 -0700 Subject: [PATCH] proc: convert to kstrto*()/kstrto*_from_user() Convert from manual allocation/copy_from_user/... to kstrto*() family which were designed for exactly that. One case can not be converted to kstrto*_from_user() to make code even more simpler because of whitespace stripping, oh well... Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/base.c | 70 ++++++++++++++++++---------------------------------------- 1 file changed, 21 insertions(+), 49 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 60c71b1..b25eee4 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1230,10 +1230,9 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file_inode(file); - char *page, *tmp; - ssize_t length; uid_t loginuid; kuid_t kloginuid; + int rv; rcu_read_lock(); if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { @@ -1242,46 +1241,28 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, } rcu_read_unlock(); - if (count >= PAGE_SIZE) - count = PAGE_SIZE - 1; - if (*ppos != 0) { /* No partial writes. */ return -EINVAL; } - page = (char*)__get_free_page(GFP_TEMPORARY); - if (!page) - return -ENOMEM; - length = -EFAULT; - if (copy_from_user(page, buf, count)) - goto out_free_page; - page[count] = '\0'; - loginuid = simple_strtoul(page, &tmp, 10); - if (tmp == page) { - length = -EINVAL; - goto out_free_page; - - } + rv = kstrtou32_from_user(buf, count, 10, &loginuid); + if (rv < 0) + return rv; /* is userspace tring to explicitly UNSET the loginuid? */ if (loginuid == AUDIT_UID_UNSET) { kloginuid = INVALID_UID; } else { kloginuid = make_kuid(file->f_cred->user_ns, loginuid); - if (!uid_valid(kloginuid)) { - length = -EINVAL; - goto out_free_page; - } + if (!uid_valid(kloginuid)) + return -EINVAL; } - length = audit_set_loginuid(kloginuid); - if (likely(length == 0)) - length = count; - -out_free_page: - free_page((unsigned long) page); - return length; + rv = audit_set_loginuid(kloginuid); + if (rv < 0) + return rv; + return count; } static const struct file_operations proc_loginuid_operations = { @@ -1335,8 +1316,9 @@ static ssize_t proc_fault_inject_write(struct file * file, const char __user * buf, size_t count, loff_t *ppos) { struct task_struct *task; - char buffer[PROC_NUMBUF], *end; + char buffer[PROC_NUMBUF]; int make_it_fail; + int rv; if (!capable(CAP_SYS_RESOURCE)) return -EPERM; @@ -1345,9 +1327,9 @@ static ssize_t proc_fault_inject_write(struct file * file, count = sizeof(buffer) - 1; if (copy_from_user(buffer, buf, count)) return -EFAULT; - make_it_fail = simple_strtol(strstrip(buffer), &end, 0); - if (*end) - return -EINVAL; + rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); + if (rv < 0) + return rv; if (make_it_fail < 0 || make_it_fail > 1) return -EINVAL; @@ -2488,32 +2470,20 @@ static ssize_t proc_coredump_filter_write(struct file *file, { struct task_struct *task; struct mm_struct *mm; - char buffer[PROC_NUMBUF], *end; unsigned int val; int ret; int i; unsigned long mask; - ret = -EFAULT; - memset(buffer, 0, sizeof(buffer)); - if (count > sizeof(buffer) - 1) - count = sizeof(buffer) - 1; - if (copy_from_user(buffer, buf, count)) - goto out_no_task; - - ret = -EINVAL; - val = (unsigned int)simple_strtoul(buffer, &end, 0); - if (*end == '\n') - end++; - if (end - buffer == 0) - goto out_no_task; + ret = kstrtouint_from_user(buf, count, 0, &val); + if (ret < 0) + return ret; ret = -ESRCH; task = get_proc_task(file_inode(file)); if (!task) goto out_no_task; - ret = end - buffer; mm = get_task_mm(task); if (!mm) goto out_no_mm; @@ -2529,7 +2499,9 @@ static ssize_t proc_coredump_filter_write(struct file *file, out_no_mm: put_task_struct(task); out_no_task: - return ret; + if (ret < 0) + return ret; + return count; } static const struct file_operations proc_coredump_filter_operations = { -- 2.7.4