X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/3903760236c30e3b5ace7a4eefac3a269d68957c..b226f5e54a60dc81db17b1260381d7dbfea3cdf1:/pexpert/i386/pe_init.c

diff --git a/pexpert/i386/pe_init.c b/pexpert/i386/pe_init.c
index 10a9fb24d..49f9caecf 100644
--- a/pexpert/i386/pe_init.c
+++ b/pexpert/i386/pe_init.c
@@ -49,7 +49,7 @@
 
 /* extern references */
 extern void pe_identify_machine(void * args);
-
+extern int kdb_printf(const char *format, ...) __printflike(1,2);
 /* private globals */
 PE_state_t  PE_state;
 
@@ -335,13 +335,23 @@ PE_reboot_on_panic(void)
 		return FALSE;
 }
 
+void
+PE_sync_panic_buffers(void)
+{
+}
+
 /* rdar://problem/21244753 */
 uint32_t
 PE_i_can_has_debugger(uint32_t *debug_flags)
 {
+#if DEVELOPMENT || DEBUG
+	if (debug_flags) {
+		assert(debug_boot_arg_inited);
+	}
+#endif
+
 #if CONFIG_CSR
-	if (csr_check(CSR_ALLOW_KERNEL_DEBUGGER) != 0 &&
-	    csr_check(CSR_ALLOW_APPLE_INTERNAL) != 0) {
+	if (csr_check(CSR_ALLOW_KERNEL_DEBUGGER) != 0) {
 		if (debug_flags)
 			*debug_flags = 0;
 		return FALSE;
@@ -352,3 +362,70 @@ PE_i_can_has_debugger(uint32_t *debug_flags)
 	}
 	return TRUE;
 }
+
+uint32_t
+PE_get_offset_into_panic_region(char *location)
+{
+	assert(panic_info != NULL);
+	assert(location > (char *) panic_info);
+
+	return (uint32_t) (location - (char *) panic_info);
+}
+
+void
+PE_init_panicheader()
+{
+	bzero(panic_info, offsetof(struct macos_panic_header, mph_data));
+	panic_info->mph_panic_log_offset = PE_get_offset_into_panic_region(debug_buf_base);
+
+	panic_info->mph_magic = MACOS_PANIC_MAGIC;
+	panic_info->mph_version = MACOS_PANIC_HEADER_CURRENT_VERSION;
+
+	return;
+}
+
+/*
+ * Tries to update the panic header to keep it consistent on nested panics.
+ *
+ * NOTE: The purpose of this function is NOT to detect/correct corruption in the panic region,
+ *       it is to update the panic header to make it consistent when we nest panics.
+ *
+ * We try to avoid nested panics/asserts on x86 because they are difficult to debug, so log any
+ * inconsistencies we find.
+ */
+void
+PE_update_panicheader_nestedpanic()
+{
+	/* If the panic log offset is not set, re-init the panic header */
+	if (panic_info->mph_panic_log_offset == 0) {
+		PE_init_panicheader();
+		panic_info->mph_panic_flags |= MACOS_PANIC_HEADER_FLAG_NESTED_PANIC;
+		return;
+	}
+
+	panic_info->mph_panic_flags |= MACOS_PANIC_HEADER_FLAG_NESTED_PANIC;
+
+	/* Usually indicative of corruption in the panic region */
+	if(!(((panic_info->mph_stackshot_offset == 0) && (panic_info->mph_stackshot_len == 0)) ||
+			((panic_info->mph_stackshot_offset != 0) && (panic_info->mph_stackshot_len != 0)))) {
+		kdb_printf("panic_info contains invalid stackshot metadata: mph_stackshot_offset 0x%x mph_stackshot_len 0x%x\n",
+				panic_info->mph_stackshot_offset, panic_info->mph_stackshot_len);
+	}
+
+	/*
+	 * macOS panic logs contain nested panic data, if we've already closed the panic log,
+	 * begin the other log.
+	 */
+	if ((panic_info->mph_panic_log_len != 0) && (panic_info->mph_other_log_offset == 0)) {
+		panic_info->mph_other_log_offset = PE_get_offset_into_panic_region(debug_buf_ptr);
+
+		/* Usually indicative of corruption in the panic region */
+		if (panic_info->mph_other_log_len != 0) {
+			kdb_printf("panic_info contains invalid other log metadata (zero offset but non-zero length), length was 0x%x, zeroing value\n",
+					panic_info->mph_other_log_len);
+			panic_info->mph_other_log_len = 0;
+		}
+	}
+
+	return;
+}