[PATCH v2 47/70] x86/logdirty: 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/mm/hap/hap.c       |  6 +++---
 xen/arch/x86/mm/shadow/common.c | 12 ++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index de4b13565ab4..ed5112b00b63 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -180,7 +180,7 @@ int hap_track_dirty_vram(struct domain *d,
  * NB: Domain that having device assigned should not set log_global. Because
  * there is no way to track the memory updating from device.
  */
-static int hap_enable_log_dirty(struct domain *d, bool_t log_global)
+static int cf_check hap_enable_log_dirty(struct domain *d, bool log_global)
 {
     struct p2m_domain *p2m = p2m_get_hostp2m(d);
 
@@ -211,7 +211,7 @@ static int hap_enable_log_dirty(struct domain *d, bool_t 
log_global)
     return 0;
 }
 
-static int hap_disable_log_dirty(struct domain *d)
+static int cf_check hap_disable_log_dirty(struct domain *d)
 {
     paging_lock(d);
     d->arch.paging.mode &= ~PG_log_dirty;
@@ -228,7 +228,7 @@ static int hap_disable_log_dirty(struct domain *d)
     return 0;
 }
 
-static void hap_clean_dirty_bitmap(struct domain *d)
+static void cf_check hap_clean_dirty_bitmap(struct domain *d)
 {
     /*
      * Switch to log-dirty mode, either by setting l1e entries of P2M table to
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 83dedc8870aa..071a19adce82 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -40,9 +40,9 @@
 
 DEFINE_PER_CPU(uint32_t,trace_shadow_path_flags);
 
-static int sh_enable_log_dirty(struct domain *, bool log_global);
-static int sh_disable_log_dirty(struct domain *);
-static void sh_clean_dirty_bitmap(struct domain *);
+static int cf_check sh_enable_log_dirty(struct domain *, bool log_global);
+static int cf_check sh_disable_log_dirty(struct domain *);
+static void cf_check sh_clean_dirty_bitmap(struct domain *);
 
 /* Set up the shadow-specific parts of a domain struct at start of day.
  * Called for every domain from arch_domain_create() */
@@ -3016,7 +3016,7 @@ static int shadow_test_disable(struct domain *d)
 /* Shadow specific code which is called in paging_log_dirty_enable().
  * Return 0 if no problem found.
  */
-static int sh_enable_log_dirty(struct domain *d, bool log_global)
+static int cf_check sh_enable_log_dirty(struct domain *d, bool log_global)
 {
     int ret;
 
@@ -3044,7 +3044,7 @@ static int sh_enable_log_dirty(struct domain *d, bool 
log_global)
 }
 
 /* shadow specfic code which is called in paging_log_dirty_disable() */
-static int sh_disable_log_dirty(struct domain *d)
+static int cf_check sh_disable_log_dirty(struct domain *d)
 {
     int ret;
 
@@ -3058,7 +3058,7 @@ static int sh_disable_log_dirty(struct domain *d)
 /* This function is called when we CLEAN log dirty bitmap. See
  * paging_log_dirty_op() for details.
  */
-static void sh_clean_dirty_bitmap(struct domain *d)
+static void cf_check sh_clean_dirty_bitmap(struct domain *d)
 {
     paging_lock(d);
     /* Need to revoke write access to the domain's pages again.
-- 
2.11.0