Merge tag 'v4.14.159' into 4.14-2.0.x-imx

This is the 4.14.159 stable release

Conflicts:
	arch/arm/Kconfig.debug
	arch/arm/boot/dts/imx7s.dtsi
	arch/arm/mach-imx/cpuidle-imx6sx.c
	drivers/crypto/caam/caamalg.c
	drivers/crypto/mxs-dcp.c
	drivers/dma/imx-sdma.c
	drivers/input/keyboard/imx_keypad.c
	drivers/net/can/flexcan.c
	drivers/net/can/rx-offload.c
	drivers/net/wireless/ath/ath10k/pci.c
	drivers/pci/dwc/pci-imx6.c
	drivers/spi/spi-fsl-lpspi.c
	drivers/usb/dwc3/gadget.c

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 9e773732520c..243fd247d04e 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -296,6 +296,10 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
 		if (IS_ENABLED(CONFIG_ARM64_UAO) &&
 		    cpus_have_const_cap(ARM64_HAS_UAO))
 			childregs->pstate |= PSR_UAO_BIT;
+
+		if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE)
+			set_ssbs_bit(childregs);
+
 		p->thread.cpu_context.x19 = stack_start;
 		p->thread.cpu_context.x20 = stk_sz;
 	}
@@ -336,6 +340,32 @@ void uao_thread_switch(struct task_struct *next)
 }
 
 /*
+ * Force SSBS state on context-switch, since it may be lost after migrating
+ * from a CPU which treats the bit as RES0 in a heterogeneous system.
+ */
+static void ssbs_thread_switch(struct task_struct *next)
+{
+	struct pt_regs *regs = task_pt_regs(next);
+
+	/*
+	 * Nothing to do for kernel threads, but 'regs' may be junk
+	 * (e.g. idle task) so check the flags and bail early.
+	 */
+	if (unlikely(next->flags & PF_KTHREAD))
+		return;
+
+	/* If the mitigation is enabled, then we leave SSBS clear. */
+	if ((arm64_get_ssbd_state() == ARM64_SSBD_FORCE_ENABLE) ||
+	    test_tsk_thread_flag(next, TIF_SSBD))
+		return;
+
+	if (compat_user_mode(regs))
+		set_compat_ssbs_bit(regs);
+	else if (user_mode(regs))
+		set_ssbs_bit(regs);
+}
+
+/*
  * We store our current task in sp_el0, which is clobbered by userspace. Keep a
  * shadow copy so that we can restore this upon entry from userspace.
  *
@@ -363,6 +393,7 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev,
 	contextidr_thread_switch(next);
 	entry_task_switch(next);
 	uao_thread_switch(next);
+	ssbs_thread_switch(next);
 
 	/*
 	 * Complete any pending TLB or cache maintenance on this CPU in case