From 4e832afb77a158a6bb59f7adac6d9db5ecd5a4b8 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.i.king@gmail.com>
Date: Tue, 5 Nov 2024 14:40:21 +0000
Subject: [PATCH 6/8] core-shim: limit _FORTIFY_SOURCE to 2 for ALT linux gcc
 for ppoll workaround

Fixes: https://github.com/ColinIanKing/stress-ng/issues/452

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
---
 Makefile    |  8 ++++++++
 core-shim.c | 40 ++++++++++++++++++++++------------------
 2 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/Makefile b/Makefile
index 2661376a258a..cb395115cd64 100644
--- a/Makefile
+++ b/Makefile
@@ -52,6 +52,14 @@ ifneq ($(shell $(CC) -v 2>&1 | grep scan-build),)
 COMPILER = scan-build
 endif
 
+#
+# check for ALT linux gcc, define HAVE_ALT_LINUX_GCC, see core-shim.c
+# https://github.com/ColinIanKing/stress-ng/issues/452
+#
+ifneq ($(shell $(CC) -v 2>&1 | grep Target | grep "alt-linux"),)
+override CFLAGS += -DHAVE_ALT_LINUX_GCC
+endif
+
 KERNEL=$(shell uname -s)
 NODENAME=$(shell uname -n)
 
diff --git a/core-shim.c b/core-shim.c
index a7813474ab86..2f4b88f8188c 100644
--- a/core-shim.c
+++ b/core-shim.c
@@ -19,6 +19,17 @@
  */
 #define STRESS_CORE_SHIM
 
+/*
+ *  For ALT Linux gcc use at most _FORTIFY_SOURCE level 2
+ *  https://github.com/ColinIanKing/stress-ng/issues/452
+ */
+#if defined(HAVE_ALT_LINUX_GCC) &&	\
+    defined(_FORTIFY_SOURCE) &&		\
+    _FORTIFY_SOURCE > 2
+#undef _FORTIFY_SOURCE
+#define _FORTIFY_SOURCE	2
+#endif
+
 #include "stress-ng.h"
 #include "core-arch.h"
 #include "core-attribute.h"
@@ -2825,7 +2836,6 @@ int shim_mseal(void *addr, size_t len, unsigned long flags)
 #endif
 }
 
-
 /*
  *  shim_ppoll()
  *	shim wrapper for ppoll
@@ -2836,26 +2846,20 @@ int shim_ppoll(
 	const struct timespec *tmo_p,
 	const sigset_t *sigmask)
 {
-
 #if defined(HAVE_PPOLL)
-
-#if defined(_FORTIFY_SOURCE)
-#undef STRESS__FORTIFY_SOURCE
-#define STRESS__FORTIFY_SOURCE _FORTIFY_SOURCE
-#undef _FORTIFY_SOURCE
-#define _FORTIFY_SOURCE 2
-#endif
-
 	return ppoll(fds, nfds, tmo_p, sigmask);
+#elif defined(__NR_ppoll) && defined(_NSIG)
+	struct timespec tval;
 
-#if defined(STRESS__FORTIFY_SOURCE)
-#undef _FORTIFY_SOURCE
-#define _FORTIFY_SOURCE STRESS__FORTIFY_SOURCE
-#undef STRESS__FORTIFY_SOURCE
-#endif
-
-#elif defined(__NR_ppoll)
-	return (int)syscall(__NR_ppoll, fds, nfds, tmo_p, sigmask);
+	/*
+	 * The kernel will update the timeout, so use a tmp val
+	 * instead
+	 */
+	if (tmo_p != NULL) {
+		tval = *tmo_p;
+		tmo_p = &tval;
+	}
+	return (int)syscall(__NR_ppoll, fds, nfds, tmo_p, sigmask, _NSIG / 8);
 #else
 	return shim_enosys(0, fds, nfds, tmo_p, sigmask);
 #endif
-- 
2.47.0