From 1dcfa7a4fa35f5bf07e5da04113329189d96e7d1 Mon Sep 17 00:00:00 2001
From: zhengweiwei <zhengweiwei11@huawei.com>
Date: Fri, 9 Aug 2024 22:06:01 +0800
Subject: [PATCH] [CFI] Implemented failure reporting mechanism for CFI checks

Desc:
- Added `cfi_fail_report.cpp` to handle CFI check failures on aarch64.
- Integrated with build system to create `clang_rt.cfi_fail_report` static library.
- Improved error reporting for easier debugging of CFI crashes.

Issue: https://gitee.com/openharmony/third_party_llvm-project/issues/IAJ36I
Signed-off-by: zhengweiwei <zhengweiwei11@huawei.com>
---
 compiler-rt/lib/cfi/CMakeLists.txt      | 10 ++++++
 compiler-rt/lib/cfi/cfi_fail_report.cpp | 41 +++++++++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 compiler-rt/lib/cfi/cfi_fail_report.cpp

diff --git a/compiler-rt/lib/cfi/CMakeLists.txt b/compiler-rt/lib/cfi/CMakeLists.txt
index cf8479d39c25..2a69b455bba9 100644
--- a/compiler-rt/lib/cfi/CMakeLists.txt
+++ b/compiler-rt/lib/cfi/CMakeLists.txt
@@ -5,6 +5,10 @@ if(OS_NAME MATCHES "Linux" OR OS_NAME MATCHES "FreeBSD" OR OS_NAME MATCHES "NetB
     cfi.cpp
     )
 
+  set(CFI_FAIL_REPORT_SOURCES
+    cfi_fail_report.cpp
+    )
+
   include_directories(..)
 
   set(CFI_CFLAGS
@@ -40,6 +44,12 @@ if(OS_NAME MATCHES "Linux" OR OS_NAME MATCHES "FreeBSD" OR OS_NAME MATCHES "NetB
                   RTUbsan
       CFLAGS ${CFI_CFLAGS} ${CFI_DIAG_CFLAGS}
       PARENT_TARGET cfi)
+    add_compiler_rt_runtime(clang_rt.cfi_fail_report
+      STATIC
+      ARCHS ${arch}
+      SOURCES ${CFI_FAIL_REPORT_SOURCES}
+      CFLAGS ${CFI_CFLAGS}
+      PARENT_TARGET cfi)
   endforeach()
 endif()
 
diff --git a/compiler-rt/lib/cfi/cfi_fail_report.cpp b/compiler-rt/lib/cfi/cfi_fail_report.cpp
new file mode 100644
index 000000000000..083707da3a24
--- /dev/null
+++ b/compiler-rt/lib/cfi/cfi_fail_report.cpp
@@ -0,0 +1,41 @@
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#if defined(__aarch64__) && defined(__OHOS__)
+#include <info/fatal_message.h>
+
+extern "C" _Noreturn void __cfi_fail_report(void);
+/**
+ * @brief Retrieves the current value of the x1 register on AArch64.
+ *
+ * This function is used in CFI checks to obtain the function address
+ * stored in the x1 register during calls involving function pointers,
+ * virtual calls (vcall), and non-virtual calls (nvcall) using vtable addresses.
+ *
+ * @return Value of the x1 register.
+ */
+uint64_t fetch_function_address(void) {
+  uint64_t val;
+  __asm__ __volatile__(
+    "mov %0, x1"
+    : "=r" (val)
+    :
+    : "memory"
+  );
+  return val;
+}
+
+_Noreturn void __cfi_fail_report(void) {
+  uint64_t function_address = fetch_function_address();
+  char message[512];
+  snprintf(message, sizeof(message),
+      "CFI check failed. Function Address: 0x%" PRIx64, function_address);
+  set_fatal_message(message);
+  abort();
+}
+#else
+extern "C" _Noreturn void __cfi_fail_report(void) {
+  abort();
+}
+#endif
-- 
Gitee