mm, oom: keep oom_adj under or at upper limit when printing

For oom_score_adj values in the range [942,999], the current
calculations will print 16 for oom_adj.  This patch simply limits the
output so output is inline with docs.

Signed-off-by: Charles Haithcock <chaithco@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lkml.kernel.org/r/20201020165130.33927-1-chaithco@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 0f70700..b362523 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1049,6 +1049,8 @@ static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
                oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
                          OOM_SCORE_ADJ_MAX;
        put_task_struct(task);
+       if (oom_adj > OOM_ADJUST_MAX)
+               oom_adj = OOM_ADJUST_MAX;
        len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
        return simple_read_from_buffer(buf, count, ppos, buffer, len);
 }