From 1cead826cb0ffe5a84c419260834b703b1af24b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlo=20Marcelo=20Arenas=20Bel=C3=B3n?= <carenas@gmail.com>
Date: Tue, 9 Oct 2018 14:55:30 -0700
Subject: [PATCH] zos: avoid UB with NULL pointer arithmetic

PR-URL: https://github.com/libuv/libuv/pull/2017
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: John Barboza <jbarboza@ca.ibm.com>
---
 src/unix/os390.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/unix/os390.c b/src/unix/os390.c
index 65e9b708..a64d098d 100644
--- a/src/unix/os390.c
+++ b/src/unix/os390.c
@@ -357,13 +357,11 @@ uint64_t uv_get_total_memory(void) {
 
 
 int uv_resident_set_memory(size_t* rss) {
-  char* psa;
   char* ascb;
   char* rax;
   size_t nframes;
 
-  psa = PSA_PTR;
-  ascb  = *(char* __ptr32 *)(psa + PSAAOLD);
+  ascb  = *(char* __ptr32 *)(PSA_PTR + PSAAOLD);
   rax = *(char* __ptr32 *)(ascb + ASCBRSME);
   nframes = *(unsigned int*)(rax + RAXFMCT);