diff options
| -rw-r--r-- | fs/proc/base.c | 33 |
1 files changed, 14 insertions, 19 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 4b27e26fc6de..3fcca77d45f1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -215,8 +215,9 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, unsigned long arg_start, arg_end, env_start, env_end; unsigned long len1, len2, len; unsigned long p; + char __user *buf0 = buf; char c; - ssize_t rv; + int rv; BUG_ON(*pos < 0); @@ -253,25 +254,20 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, len2 = env_end - env_start; /* Empty ARGV. */ - if (len1 == 0) { - rv = 0; - goto out_free_page; - } + if (len1 == 0) + goto end; + /* * Inherently racy -- command line shares address space * with code and data. */ - if (access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON) != 1) { - rv = 0; - goto out_free_page; - } - - rv = 0; + if (access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON) != 1) + goto end; if (c == '\0') { /* Command line (set of strings) occupies whole ARGV. */ if (len1 <= *pos) - goto out_free_page; + goto end; p = arg_start + *pos; len = len1 - *pos; @@ -281,7 +277,7 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, nr_read = min3(count, len, PAGE_SIZE); nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON); if (nr_read == 0) - goto out_free_page; + goto end; if (copy_to_user(buf, page, nr_read)) { rv = -EFAULT; @@ -292,7 +288,6 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, len -= nr_read; buf += nr_read; count -= nr_read; - rv += nr_read; } } else { /* @@ -323,7 +318,7 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, nr_read = min3(count, len, PAGE_SIZE); nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON); if (nr_read == 0) - goto out_free_page; + goto end; /* * Command line can be shorter than whole ARGV @@ -340,10 +335,9 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, len -= nr_write; buf += nr_write; count -= nr_write; - rv += nr_write; if (nr_write < nr_read) - goto out_free_page; + goto end; } /* Only first chunk can be read partially. */ @@ -352,12 +346,13 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, } } +end: + *pos += buf - buf0; + rv = buf - buf0; out_free_page: free_page((unsigned long)page); out_mmput: mmput(mm); - if (rv > 0) - *pos += rv; return rv; } |