From e3e12f52b214121840b44c91de5b3e5af5d3eb84 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 06 Nov 2023 03:04:41 +0000
Subject: [PATCH] rk3568 rt init
---
kernel/arch/x86/include/asm/stackprotector.h | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/kernel/arch/x86/include/asm/stackprotector.h b/kernel/arch/x86/include/asm/stackprotector.h
index 9c556ea..b136992 100644
--- a/kernel/arch/x86/include/asm/stackprotector.h
+++ b/kernel/arch/x86/include/asm/stackprotector.h
@@ -65,7 +65,7 @@
*/
static __always_inline void boot_init_stack_canary(void)
{
- u64 canary;
+ u64 uninitialized_var(canary);
u64 tsc;
#ifdef CONFIG_X86_64
@@ -76,8 +76,14 @@
* of randomness. The TSC only matters for very early init,
* there it already has some randomness on most systems. Later
* on during the bootup the random pool has true entropy too.
+ * For preempt-rt we need to weaken the randomness a bit, as
+ * we can't call into the random generator from atomic context
+ * due to locking constraints. We just leave canary
+ * uninitialized and use the TSC based randomness on top of it.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
get_random_bytes(&canary, sizeof(canary));
+#endif
tsc = rdtsc();
canary += tsc + (tsc << 32UL);
canary &= CANARY_MASK;
--
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