[PATCH v5 01/10] ARM: bugs: Check in the vtable instead of defined aliases

[Linus Walleij]

Instead of checking if cpu_check_bugs() exist, check for this
callback directly in the CPU vtable: this is better because the
function is just a define to the vtable entry and this is why
the code works. But we want to be able to specify a proper
function for cpu_check_bugs() so look into the vtable instead.

In bugs.c assign PROC_VTABLE(switch_mm) instead of
assigning cpu_do_switch_mm where again this is just a define
into the vtable: this makes it possible to make
cpu_do_switch_mm() into a real function.

Tested-by: Kees Cook <keescook at chromium.org>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
 arch/arm/kernel/bugs.c     | 2 +-
 arch/arm/mm/proc-v7-bugs.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 087bce6ec8e9..35d39efb51ed 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -7,7 +7,7 @@
 void check_other_bugs(void)
 {
 #ifdef MULTI_CPU
-	if (cpu_check_bugs)
+	if (PROC_VTABLE(check_bugs))
 		cpu_check_bugs();
 #endif
 }
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 8bc7a2d6d6c7..ea3ee2bd7b56 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -87,14 +87,14 @@ static unsigned int spectre_v2_install_workaround(unsigned int method)
 	case SPECTRE_V2_METHOD_HVC:
 		per_cpu(harden_branch_predictor_fn, cpu) =
 			call_hvc_arch_workaround_1;
-		cpu_do_switch_mm = cpu_v7_hvc_switch_mm;
+		PROC_VTABLE(switch_mm) = cpu_v7_hvc_switch_mm;
 		spectre_v2_method = "hypervisor";
 		break;
 
 	case SPECTRE_V2_METHOD_SMC:
 		per_cpu(harden_branch_predictor_fn, cpu) =
 			call_smc_arch_workaround_1;
-		cpu_do_switch_mm = cpu_v7_smc_switch_mm;
+		PROC_VTABLE(switch_mm) = cpu_v7_smc_switch_mm;
 		spectre_v2_method = "firmware";
 		break;
 	}

-- 
2.44.0