debug: add helper functions for cap type checking

This reduces the usage of magic values to one file only.

Signed-off-by: Axel Heider <axelheider@gmx.de>

CMakeLists.txt

@@ -12,6 +12,7 @@
 
 cmake_minimum_required(VERSION 3.7.2)
 
+add_subdirectory(libsel4debug)
 add_subdirectory(libsel4allocman)
 add_subdirectory(libsel4vka)
 add_subdirectory(libsel4utils)
@@ -20,7 +21,6 @@ add_subdirectory(libsel4platsupport)
 add_subdirectory(libsel4serialserver)
 add_subdirectory(libsel4simple)
 add_subdirectory(libsel4simple-default)
-add_subdirectory(libsel4debug)
 add_subdirectory(libsel4test)
 add_subdirectory(libsel4sync)
 add_subdirectory(libsel4muslcsys)

libsel4debug/include/sel4debug/debug.h

@@ -27,5 +27,25 @@ __attribute__((no_instrument_function));
 
 void debug_cap_identify(seL4_CPtr cap);
 
+static inline int debug_cap_is_valid(seL4_CPtr cap)
+{
+    return (0 != seL4_DebugCapIdentify(cap));
+}
+
+static inline int debug_cap_is_endpoint(seL4_CPtr cap)
+{
+    // there is kernel/generated/arch/object/structures_gen.h that defines
+    // cap_endpoint_cap = 4, but we can't include it here
+    return (4 == seL4_DebugCapIdentify(cap));
+}
+
+static inline int debug_cap_is_notification(seL4_CPtr cap)
+{
+    // there is kernel/generated/arch/object/structures_gen.h that defines
+    // cap_notification_cap = 6, but we can't include it here
+    return (6 == seL4_DebugCapIdentify(cap));
+}
+
+
 void debug_print_bootinfo(seL4_BootInfo *info);
 

libsel4sync/CMakeLists.txt

@@ -20,11 +20,7 @@ list(SORT deps)
 
 add_library(sel4sync STATIC EXCLUDE_FROM_ALL ${deps})
 
-target_include_directories(
-    sel4sync
-    PUBLIC
-        include
-)
+target_include_directories(sel4sync PUBLIC include)
 
 target_link_libraries(
     sel4sync
@@ -37,3 +33,7 @@ target_link_libraries(
         sel4_
         autoconf
 )
+
+if(KernelDebugBuild)
+    target_link_libraries(sel4sync PUBLIC sel4debug)
+endif()

libsel4sync/include/sync/bin_sem.h

@@ -15,6 +15,9 @@
 #include <autoconf.h>
 #include <assert.h>
 #include <sel4/sel4.h>
+#ifdef CONFIG_DEBUG_BUILD
+#include <sel4debug/debug.h>
+#endif
 #include <vka/vka.h>
 #include <vka/object.h>
 #include <stddef.h>
@@ -44,7 +47,7 @@ static inline int sync_bin_sem_init(sync_bin_sem_t *sem, seL4_CPtr notification,
 
 #ifdef CONFIG_DEBUG_BUILD
     /* Check the cap actually is a notification. */
-    assert(seL4_DebugCapIdentify(notification) == 6);
+    assert(debug_cap_is_notification(notification));
 #endif
 
     sem->notification.cptr = notification;

libsel4sync/include/sync/condition_var.h

@@ -14,6 +14,9 @@
 
 #include <autoconf.h>
 #include <sel4/sel4.h>
+#ifdef CONFIG_DEBUG_BUILD
+#include <sel4debug/debug.h>
+#endif
 #include <vka/vka.h>
 #include <vka/object.h>
 #include <platsupport/sync/atomic.h>
@@ -38,7 +41,7 @@ static inline int sync_cv_init(sync_cv_t *cv, seL4_CPtr notification)
 
 #ifdef CONFIG_DEBUG_BUILD
     /* Check the cap actually is a notification. */
-    assert(seL4_DebugCapIdentify(notification) == 6);
+    assert(debug_cap_is_notification(notification));
 #endif
 
     cv->notification.cptr = notification;

libsel4sync/include/sync/sem-bare.h

@@ -22,14 +22,17 @@
 #include <assert.h>
 #include <limits.h>
 #include <sel4/sel4.h>
+#ifdef CONFIG_DEBUG_BUILD
+#include <sel4debug/debug.h>
+#endif
 #include <stddef.h>
 #include <platsupport/sync/atomic.h>
 
 static inline int sync_sem_bare_wait(seL4_CPtr ep, volatile int *value)
 {
 #ifdef CONFIG_DEBUG_BUILD
     /* Check the cap actually is an EP. */
-    assert(seL4_DebugCapIdentify(ep) == 4);
+    assert(debug_cap_is_endpoint(ep));
 #endif
     assert(value != NULL);
     int oldval;
@@ -80,7 +83,7 @@ static inline int sync_sem_bare_post(seL4_CPtr ep, volatile int *value)
 {
 #ifdef CONFIG_DEBUG_BUILD
     /* Check the cap actually is an EP. */
-    assert(seL4_DebugCapIdentify(ep) == 4);
+    assert(debug_cap_is_endpoint(ep));
 #endif
     assert(value != NULL);
     /* We can do an "unsafe" increment here because we know the lock cannot be

libsel4sync/include/sync/sem.h

@@ -15,6 +15,9 @@
 #include <autoconf.h>
 #include <assert.h>
 #include <sel4/sel4.h>
+#ifdef CONFIG_DEBUG_BUILD
+#include <sel4debug/debug.h>
+#endif
 #include <vka/vka.h>
 #include <vka/object.h>
 #include <stddef.h>
@@ -38,7 +41,7 @@ static inline int sync_sem_init(sync_sem_t *sem, seL4_CPtr ep, int value)
     }
 #ifdef CONFIG_DEBUG_BUILD
     /* Check the cap actually is an EP. */
-    assert(seL4_DebugCapIdentify(ep) == 4);
+    assert(debug_cap_is_endpoint(ep));
 #endif
 
     sem->ep.cptr = ep;

libsel4sync/src/recursive_mutex.c

@@ -17,6 +17,9 @@
 #include <limits.h>
 
 #include <sel4/sel4.h>
+#ifdef CONFIG_DEBUG_BUILD
+#include <sel4debug/debug.h>
+#endif
 
 static void *thread_id(void)
 {
@@ -31,7 +34,7 @@ int sync_recursive_mutex_init(sync_recursive_mutex_t *mutex, seL4_CPtr notificat
     }
 #ifdef CONFIG_DEBUG_BUILD
     /* Check the cap actually is a notification. */
-    assert(seL4_DebugCapIdentify(notification) == 6);
+    assert(debug_cap_is_notification(notification));
 #endif
 
     mutex->notification.cptr = notification;

libsel4vka/CMakeLists.txt

@@ -69,3 +69,6 @@ target_link_libraries(
         sel4vka_Config
         sel4_autoconf
 )
+if(KernelDebugBuild)
+    target_link_libraries(sel4vka PUBLIC sel4debug)
+endif()

libsel4vka/include/vka/vka.h

@@ -17,6 +17,9 @@
 
 #include <sel4/sel4.h>
 #include <sel4/types.h>
+#ifdef CONFIG_DEBUG_BUILD
+#include <sel4debug/debug.h>
+#endif
 #include <assert.h>
 #include <stdint.h>
 #include <utils/util.h>
@@ -192,7 +195,7 @@ static inline int vka_cspace_alloc_path(vka_t *vka, cspacepath_t *res)
 static inline void vka_cspace_free(vka_t *vka, seL4_CPtr slot)
 {
 #ifdef CONFIG_DEBUG_BUILD
-    if (seL4_DebugCapIdentify(slot) != 0) {
+    if (debug_cap_is_valid(slot)) {
         ZF_LOGF("slot is not free: call vka_cnode_delete first");
         /* this terminates the system */
     }