From: Nick Terrell <terrelln@fb.com>
Date: Tue, 13 Dec 2022 23:03:23 +0000 (-0800)
Subject: [contrib][linux-kernel] Fix stack detection for newer gcc
X-Git-Tag: v1.5.4^2~120
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e767d5c7c144ab911842229a9a8fee527d9616e9;p=thirdparty%2Fzstd.git

[contrib][linux-kernel] Fix stack detection for newer gcc

Newer gcc versions were getting smart and omitting the `memset()`.
Get around this issue by outlining the `memset()` into a different
function. This test is still hacky, but it works...
---

diff --git a/contrib/linux-kernel/test/test.c b/contrib/linux-kernel/test/test.c
index 6cd1730bb..67d248e0c 100644
--- a/contrib/linux-kernel/test/test.c
+++ b/contrib/linux-kernel/test/test.c
@@ -186,11 +186,14 @@ static void __attribute__((noinline)) use(void *x) {
   asm volatile("" : "+r"(x));
 }
 
+static void __attribute__((noinline)) fill_stack(void) {
+  memset(g_stack, 0x33, 8192);
+}
+
 static void __attribute__((noinline)) set_stack(void) {
 
   char stack[8192];
   g_stack = stack;
-  memset(g_stack, 0x33, 8192);
   use(g_stack);
 }
 
@@ -208,6 +211,7 @@ static void __attribute__((noinline)) check_stack(void) {
 
 static void test_stack_usage(test_data_t const *data) {
   set_stack();
+  fill_stack();
   test_f2fs();
   test_btrfs(data);
   test_decompress_unzstd(data);