[PATCH 1/3] docs, parallelism: Fix failure path and add comment

[Kees Cook]

Rasmus noted that the failure path didn't correctly exit. Fix this and
add another comment about GNU Make's job server environment variable
names over time.

Reported-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/eb25959a-9ec4-3530-2031-d9d716b40b20@xxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 scripts/jobserver-count | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scripts/jobserver-count b/scripts/jobserver-count
index 0b482d6884d2..6e15b38df3d0 100755
--- a/scripts/jobserver-count
+++ b/scripts/jobserver-count
@@ -24,6 +24,8 @@ try:
 	flags = os.environ['MAKEFLAGS']
 
 	# Look for "--jobserver=R,W"
+	# Note that GNU Make has used --jobserver-fds and --jobserver-auth
+	# so this handles all of them.
 	opts = [x for x in flags.split(" ") if x.startswith("--jobserver")]
 
 	# Parse out R,W file descriptor numbers and set them nonblocking.
@@ -53,6 +55,7 @@ os.write(writer, jobs)
 # If the jobserver was (impossibly) full or communication failed, use default.
 if len(jobs) < 1:
 	print(default)
+	sys.exit(0)
 
 # Report available slots (with a bump for our caller's reserveration).
 print(len(jobs) + 1)
-- 
2.17.1