diff options
Diffstat (limited to 'features/rt/powerpc-stackprotector-work-around-stack-guard-init-.patch')
| -rw-r--r-- | features/rt/powerpc-stackprotector-work-around-stack-guard-init-.patch | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/features/rt/powerpc-stackprotector-work-around-stack-guard-init-.patch b/features/rt/powerpc-stackprotector-work-around-stack-guard-init-.patch new file mode 100644 index 00000000..4d3d3734 --- /dev/null +++ b/features/rt/powerpc-stackprotector-work-around-stack-guard-init-.patch @@ -0,0 +1,35 @@ +From 77000da2f2cf79d495a6d07abfbe32ebf4cd279f 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 183/191] powerpc/stackprotector: work around stack-guard init + from atomic + +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; +-- +2.19.1 + |