[PATCH 2/7] powerpc/security: change link stack flush state to the flush type enum
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2020-06-09 07:13:42
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Prepare to allow for hardware link stack flushing by using the none/sw/hw type, same as the count cache state. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/security.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index df2a3eff950b..28f4cb062f69 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c@@ -27,7 +27,7 @@ enum branch_cache_flush_type { BRANCH_CACHE_FLUSH_HW = 0x4, }; static enum branch_cache_flush_type count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE; -static bool link_stack_flush_enabled; +static enum branch_cache_flush_type link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE; bool barrier_nospec_enabled; static bool no_nospec;
@@ -219,7 +219,7 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c if (ccd) seq_buf_printf(&s, "Indirect branch cache disabled"); - if (link_stack_flush_enabled) + if (link_stack_flush_type == BRANCH_CACHE_FLUSH_SW) seq_buf_printf(&s, ", Software link stack flush"); } else if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
@@ -228,7 +228,7 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW) seq_buf_printf(&s, " (hardware accelerated)"); - if (link_stack_flush_enabled) + if (link_stack_flush_type == BRANCH_CACHE_FLUSH_SW) seq_buf_printf(&s, ", Software link stack flush"); } else if (btb_flush_enabled) {
@@ -447,7 +447,7 @@ static void toggle_branch_cache_flush(bool enable) ppc_inst(PPC_INST_NOP)); #endif pr_info("link-stack-flush: software flush disabled.\n"); - link_stack_flush_enabled = false; + link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE; no_count_cache_flush(); return; }
@@ -463,7 +463,7 @@ static void toggle_branch_cache_flush(bool enable) #endif pr_info("link-stack-flush: software flush enabled.\n"); - link_stack_flush_enabled = true; + link_stack_flush_type = BRANCH_CACHE_FLUSH_SW; // If we just need to flush the link stack, patch an early return if (!security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
--
2.23.0