From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: proc: more "unsigned int" in /proc/*/cmdline 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. Link: http://lkml.kernel.org/r/20180221192605.GB28548@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/base.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-) diff -puN fs/proc/base.c~proc-more-unsigned-int-in-proc-cmdline fs/proc/base.c --- a/fs/proc/base.c~proc-more-unsigned-int-in-proc-cmdline +++ a/fs/proc/base.c @@ -261,9 +261,10 @@ static ssize_t proc_pid_cmdline_read(str * Inherently racy -- command line shares address space * with code and data. */ - rv = access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON); - if (rv <= 0) + if (access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON) != 1) { + rv = 0; goto out_free_page; + } rv = 0; @@ -275,14 +276,11 @@ static ssize_t proc_pid_cmdline_read(str p = arg_start + *pos; len = len1 - *pos; while (count > 0 && len > 0) { - unsigned int _count; - int nr_read; + unsigned int nr_read; - _count = min3(count, len, PAGE_SIZE); - nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON); - 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, FOLL_ANON); + if (nr_read == 0) goto out_free_page; if (copy_to_user(buf, page, nr_read)) { @@ -320,15 +318,12 @@ static ssize_t proc_pid_cmdline_read(str 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, FOLL_ANON); - 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, FOLL_ANON); + if (nr_read == 0) goto out_free_page; /* _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
