1 files changed, 36 insertions, 0 deletions
diff --git a/debian/patches-rt/0278-powerpc-stackprotector-work-around-stack-guard-init-.patch b/debian/patches-rt/0278-powerpc-stackprotector-work-around-stack-guard-init-.patch
new file mode 100644
index 000000000..a46f2fadf
--- /dev/null
+++ b/debian/patches-rt/0278-powerpc-stackprotector-work-around-stack-guard-init-.patch
@@ -0,0 +1,36 @@
+From fdb2b0b4898a26e8910152ed1ab6fa6748d1b839 Mon Sep 17 00:00:00 2001
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Tue, 26 Mar 2019 18:31:29 +0100
+Subject: [PATCH 278/323] powerpc/stackprotector: work around stack-guard init
+ from atomic
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+This is invoked from the secondary CPU in atomic context. On x86 we use
+tsc instead. On Power we XOR it against mftb() so lets use stack address
+as the initial value.
+
+Cc: stable-rt@vger.kernel.org
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ arch/powerpc/include/asm/stackprotector.h | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/arch/powerpc/include/asm/stackprotector.h b/arch/powerpc/include/asm/stackprotector.h
+index 1c8460e23583..b1653c160bab 100644
+--- a/arch/powerpc/include/asm/stackprotector.h
++++ b/arch/powerpc/include/asm/stackprotector.h
+@@ -24,7 +24,11 @@ static __always_inline void boot_init_stack_canary(void)
+ 	unsigned long canary;
+ 
+ 	/* Try to get a semi random initial value. */
++#ifdef CONFIG_PREEMPT_RT
++	canary = (unsigned long)&canary;
++#else
+ 	canary = get_random_canary();
++#endif
+ 	canary ^= mftb();
+ 	canary ^= LINUX_VERSION_CODE;
+ 	canary &= CANARY_MASK;
+-- 
+2.43.0
+