Refactor x86_gen. It is still wrong.

ext/arch.h

@@ -13,6 +13,8 @@
 #error "Unsupported architecture! Cannot continue compilation."
 #endif
 
+#include "x86_gen.h"
+
 /*
  * arch_get_st2_tramp - architecture specific stage 2 trampoline getter
  *

ext/x86_gen.c

@@ -0,0 +1,73 @@
+#include <assert.h>
+#include <stdint.h>
+#include "arch.h"
+#include "x86_gen.h"
+
+/*
+ * arch_insert_st1_tramp - architecture specific stage 1 trampoline insert
+ *
+ * Given:
+ *      - a start address (start),
+ *      - the absolute address of the function to intercept (trampee),
+ *      - the absolute address of the code to execute instead (tramp),
+ *
+ * This function will:
+ *    - interpret address start as a struct st1_base,
+ *    - check that the instruction at call is actually a call
+ *    - if so, check that the target of the call is trampee
+ *    - and change the target to tramp
+ *
+ * Returns 0 on success, 1 otherwise.
+ */
+int
+arch_insert_st1_tramp(void *start, void *trampee, void *tramp)
+{
+  assert(start != NULL);
+  assert(trampee != NULL);
+  assert(tramp != NULL);
+
+  int32_t fn_addr = 0;
+  struct st1_base *check = start;
+
+  if (check->call == 0xe8) {
+    fn_addr = check->displacement;
+    if ((trampee - (void *)(check + 1)) == fn_addr) {
+      WRITE_INSTRUCTIONS(&check->displacement,
+                         sizeof(*check),
+                         (check->displacement = (tramp - (void *)(check + 1))));
+      return 0;
+    }
+  }
+
+  return 1;
+}
+
+/*
+ * arch_get_st2_tramp - architecture specific stage 2 tramp accessor. This
+ * function returns a pointer to the default stage 2 trampoline setting size
+ * if a non-NULL pointer was passed in.
+ */
+void *
+arch_get_st2_tramp(size_t *size)
+{
+  if (size) {
+    *size = sizeof(default_st2_tramp);
+  }
+
+  return &default_st2_tramp;
+}
+
+/*
+ * arch_get_inline_st2_tramp - architecture specific inline stage 2 tramp
+ * accessor. This function returns a pointer to the default inline stage 2
+ *  trampoline setting size if a non-NULL pointer was passed in.
+ */
+void *
+arch_get_inline_st2_tramp(size_t *size)
+{
+  if (size) {
+    *size = sizeof(default_inline_st2_tramp);
+  }
+
+  return &default_inline_st2_tramp;
+}

ext/x86_gen.h

@@ -15,7 +15,7 @@
  *
  * For example:   callq <0xdeadbeef> #rb_newobj
  */
-struct st1_base {
+static struct st1_base {
   unsigned char call;
   int32_t displacement;
 } __attribute__((__packed__)) st1_mov = {
@@ -53,7 +53,7 @@ copy_instructions(void *dest, void *src, size_t count)
 
   mprotect(aligned_addr, (dest - aligned_addr) + count, PROT_READ|PROT_WRITE|PROT_EXEC);
   memcpy(dest, src, count);
-  mprotect(aligned_addr, (dest - aligned_addr) + count, PROT_READ|PROT_EXEC);
+ // mprotect(aligned_addr, (dest - aligned_addr) + count, PROT_READ|PROT_EXEC);
 
   return;
 }
@@ -70,72 +70,4 @@ copy_instructions(void *dest, void *src, size_t count)
   mprotect(aligned_addr, count, PROT_READ | PROT_EXEC); \
 } while (0)
 
-/*
- * arch_insert_st1_tramp - architecture specific stage 1 trampoline insert
- *
- * Given:
- *      - a start address (start),
- *      - the absolute address of the function to intercept (trampee),
- *      - the absolute address of the code to execute instead (tramp),
- *
- * This function will:
- *    - interpret address start as a struct st1_base,
- *    - check that the instruction at call is actually a call
- *    - if so, check that the target of the call is trampee
- *    - and change the target to tramp
- *
- * Returns 0 on success, 1 otherwise.
- */
-int
-arch_insert_st1_tramp(void *start, void *trampee, void *tramp)
-{
-  assert(start != NULL);
-  assert(trampee != NULL);
-  assert(tramp != NULL);
-
-  int32_t fn_addr = 0;
-  struct st1_base *check = start;
-
-  if (check->call == 0xe8) {
-    fn_addr = check->displacement;
-    if ((trampee - (void *)(check + 1)) == fn_addr) {
-      WRITE_INSTRUCTIONS(&check->displacement,
-                         sizeof(*check),
-                         (check->displacement = (tramp - (void *)(check + 1))));
-      return 0;
-    }
-  }
-
-  return 1;
-}
-
-/*
- * arch_get_st2_tramp - architecture specific stage 2 tramp accessor. This
- * function returns a pointer to the default stage 2 trampoline setting size
- * if a non-NULL pointer was passed in.
- */
-void *
-arch_get_st2_tramp(size_t *size)
-{
-  if (size) {
-    *size = sizeof(default_st2_tramp);
-  }
-
-  return &default_st2_tramp;
-}
-
-/*
- * arch_get_inline_st2_tramp - architecture specific inline stage 2 tramp
- * accessor. This function returns a pointer to the default inline stage 2
- *  trampoline setting size if a non-NULL pointer was passed in.
- */
-void *
-arch_get_inline_st2_tramp(size_t *size)
-{
-  if (size) {
-    *size = sizeof(default_inline_st2_tramp);
-  }
-
-  return &default_inline_st2_tramp;
-}
 #endif