access_remote_vm() doesn't return negative errors, it returns number of bytes read/written (0 if error occurs). This allows to delete some comparisons which never trigger.
Reuse "nr_read" variable while I'm at it. Signed-off-by: Alexey Dobriyan <[email protected]> --- fs/proc/base.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -280,9 +280,10 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, * Inherently racy -- command line shares address space * with code and data. */ - rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); - if (rv <= 0) + if (access_remote_vm(mm, arg_end - 1, &c, 1, 0) != 1) { + rv = 0; goto out_free_page; + } rv = 0; @@ -294,14 +295,11 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, p = arg_start + *pos; len = len1 - *pos; while (count > 0 && len > 0) { - unsigned int _count; - int nr_read; - - _count = min3(count, len, PAGE_SIZE); - nr_read = access_remote_vm(mm, p, page, _count, 0); - if (nr_read < 0) - rv = nr_read; - if (nr_read <= 0) + unsigned int nr_read; + + nr_read = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, nr_read, 0); + if (nr_read == 0) goto out_free_page; if (copy_to_user(buf, page, nr_read)) { @@ -339,15 +337,12 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, p = cmdline[i].p + pos1; len = cmdline[i].len - pos1; while (count > 0 && len > 0) { - unsigned int _count, l; - int nr_read; + unsigned int nr_read, l; bool final; - _count = min3(count, len, PAGE_SIZE); - nr_read = access_remote_vm(mm, p, page, _count, 0); - if (nr_read < 0) - rv = nr_read; - if (nr_read <= 0) + nr_read = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, nr_read, 0); + if (nr_read == 0) goto out_free_page; /*
