[PATCH v2 45/70] x86/cpu: CFI hardening

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Control Flow Integrity schemes use toolchain and optionally hardware support
to help protect against call/jump/return oriented programming attacks.

Use cf_check to annotate function pointer targets for the toolchain.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/cpu/amd.c      | 6 +++---
 xen/arch/x86/cpu/centaur.c  | 2 +-
 xen/arch/x86/cpu/common.c   | 2 +-
 xen/arch/x86/cpu/cpu.h      | 2 +-
 xen/arch/x86/cpu/hygon.c    | 2 +-
 xen/arch/x86/cpu/intel.c    | 6 +++---
 xen/arch/x86/cpu/shanghai.c | 2 +-
 7 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index 2d18223f20ef..4999f8be2b11 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -208,7 +208,7 @@ static void __init noinline probe_masking_msrs(void)
  * parameter of NULL is used to context switch to the default host state (by
  * the cpu bringup-code, crash path, etc).
  */
-static void amd_ctxt_switch_masking(const struct vcpu *next)
+static void cf_check amd_ctxt_switch_masking(const struct vcpu *next)
 {
        struct cpuidmasks *these_masks = &this_cpu(cpuidmasks);
        const struct domain *nextd = next ? next->domain : NULL;
@@ -634,7 +634,7 @@ void amd_log_freq(const struct cpuinfo_x86 *c)
 #undef FREQ
 }
 
-void early_init_amd(struct cpuinfo_x86 *c)
+void cf_check early_init_amd(struct cpuinfo_x86 *c)
 {
        if (c == &boot_cpu_data)
                amd_init_levelling();
@@ -744,7 +744,7 @@ void __init detect_zen2_null_seg_behaviour(void)
 
 }
 
-static void init_amd(struct cpuinfo_x86 *c)
+static void cf_check init_amd(struct cpuinfo_x86 *c)
 {
        u32 l, h;
 
diff --git a/xen/arch/x86/cpu/centaur.c b/xen/arch/x86/cpu/centaur.c
index 34a5bfcaeef2..eac49d78db62 100644
--- a/xen/arch/x86/cpu/centaur.c
+++ b/xen/arch/x86/cpu/centaur.c
@@ -48,7 +48,7 @@ static void init_c3(struct cpuinfo_x86 *c)
        display_cacheinfo(c);
 }
 
-static void init_centaur(struct cpuinfo_x86 *c)
+static void cf_check init_centaur(struct cpuinfo_x86 *c)
 {
        if (c->x86 == 6)
                init_c3(c);
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index c4f07f2d1da4..6b674bf15e8b 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -104,7 +104,7 @@ bool __init is_forced_cpu_cap(unsigned int cap)
        return test_bit(cap, forced_caps);
 }
 
-static void default_init(struct cpuinfo_x86 * c)
+static void cf_check default_init(struct cpuinfo_x86 * c)
 {
        /* Not much we can do here... */
        /* Check if at least it has cpuid */
diff --git a/xen/arch/x86/cpu/cpu.h b/xen/arch/x86/cpu/cpu.h
index b593bd85f04f..a228087f9157 100644
--- a/xen/arch/x86/cpu/cpu.h
+++ b/xen/arch/x86/cpu/cpu.h
@@ -18,7 +18,7 @@ extern void display_cacheinfo(struct cpuinfo_x86 *c);
 extern void detect_ht(struct cpuinfo_x86 *c);
 extern bool detect_extended_topology(struct cpuinfo_x86 *c);
 
-void early_init_amd(struct cpuinfo_x86 *c);
+void cf_check early_init_amd(struct cpuinfo_x86 *c);
 void amd_log_freq(const struct cpuinfo_x86 *c);
 void amd_init_lfence(struct cpuinfo_x86 *c);
 void amd_init_ssbd(const struct cpuinfo_x86 *c);
diff --git a/xen/arch/x86/cpu/hygon.c b/xen/arch/x86/cpu/hygon.c
index cdc94130dd2e..3c8516e014c3 100644
--- a/xen/arch/x86/cpu/hygon.c
+++ b/xen/arch/x86/cpu/hygon.c
@@ -28,7 +28,7 @@ static void hygon_get_topology(struct cpuinfo_x86 *c)
                                c->phys_proc_id, c->cpu_core_id);
 }
 
-static void init_hygon(struct cpuinfo_x86 *c)
+static void cf_check init_hygon(struct cpuinfo_x86 *c)
 {
        unsigned long long value;
 
diff --git a/xen/arch/x86/cpu/intel.c b/xen/arch/x86/cpu/intel.c
index 06b0e552cc8f..ff7c02223687 100644
--- a/xen/arch/x86/cpu/intel.c
+++ b/xen/arch/x86/cpu/intel.c
@@ -176,7 +176,7 @@ static void __init probe_masking_msrs(void)
  * parameter of NULL is used to context switch to the default host state (by
  * the cpu bringup-code, crash path, etc).
  */
-static void intel_ctxt_switch_masking(const struct vcpu *next)
+static void cf_check intel_ctxt_switch_masking(const struct vcpu *next)
 {
        struct cpuidmasks *these_masks = &this_cpu(cpuidmasks);
        const struct domain *nextd = next ? next->domain : NULL;
@@ -286,7 +286,7 @@ static void __init noinline intel_init_levelling(void)
                ctxt_switch_masking = intel_ctxt_switch_masking;
 }
 
-static void early_init_intel(struct cpuinfo_x86 *c)
+static void cf_check early_init_intel(struct cpuinfo_x86 *c)
 {
        u64 misc_enable, disable;
 
@@ -500,7 +500,7 @@ static void intel_log_freq(const struct cpuinfo_x86 *c)
     }
 }
 
-static void init_intel(struct cpuinfo_x86 *c)
+static void cf_check init_intel(struct cpuinfo_x86 *c)
 {
        /* Detect the extended topology information if available */
        detect_extended_topology(c);
diff --git a/xen/arch/x86/cpu/shanghai.c b/xen/arch/x86/cpu/shanghai.c
index 08a81f0f0c8e..95ae544f8c54 100644
--- a/xen/arch/x86/cpu/shanghai.c
+++ b/xen/arch/x86/cpu/shanghai.c
@@ -3,7 +3,7 @@
 #include <asm/processor.h>
 #include "cpu.h"
 
-static void init_shanghai(struct cpuinfo_x86 *c)
+static void cf_check init_shanghai(struct cpuinfo_x86 *c)
 {
     if ( cpu_has(c, X86_FEATURE_ITSC) )
     {
-- 
2.11.0