Add a poor-man's disassembler to inspect crashes in JIT'ed code.

diff --git a/tools/gdbjithelper/Android.mk b/tools/gdbjithelper/Android.mk
new file mode 100644 (file)
index 0000000..e551b65
--- /dev/null
+++ b/tools/gdbjithelper/Android.mk
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := gdbjithelper.c
+LOCAL_CFLAGS += -O0 -g
+LOCAL_MODULE := gdbjithelper
+LOCAL_MODULE_TAGS := eng
+include $(BUILD_EXECUTABLE)

diff --git a/tools/gdbjithelper/README.txt b/tools/gdbjithelper/README.txt
new file mode 100644 (file)
index 0000000..032b244
--- /dev/null
+++ b/tools/gdbjithelper/README.txt
@@ -0,0 +1,66 @@
+Step 1
+
+If you see a native crash in the bugreport and the PC/LR are pointing to the
+code cache address range*, copy them into codePC and codeLR in gdbjithelper.c,
+respectively.
+
+*Caveats: debuggerd doesn't know the range of code cache. So apply this tool if
+the crashing address is not contained by any shared library.
+
+       #00  pc 463ba204
+       #01  lr 463ba1c9  <unknown>
+
+code around pc:
+463ba1e4 4300e119 4284aa7a f927f7b7 40112268
+463ba1f4 419da7f8 00002000 01000100 00080000
+463ba204 4191debc 01010000 4284aa74 68b00054
+463ba214 045cf205 cc016468 0718f2a5 d0102800
+463ba224 4c13c701 a20aa108 efb0f775 e008e010
+
+code around lr:
+463ba1a8 42e19e58 f2050050 cc01045c 0718f2a5
+463ba1b8 d00f2800 4c13c701 a20aa108 efe4f775
+463ba1c8 e007e010 29006bf8 6e77dc01 a10347b8
+463ba1d8 ef60f775 6db1480b 1c2d4788 4300e119
+463ba1e8 4284aa7a f927f7b7 40112268 419da7f8
+
+
+Step 2
+ 
+Push $OUT/EXECUTABLES/gdbjithelper_intermediates/LINKED/gdbjithelper to
+/system/bin on the device or emulator
+
+
+Step 3
+
+Debug the executable as usual:
+
+adb forward tcp:5039 tcp:5039
+adb shell gdbserver :5039 /system/bin/gdbjithelper &
+arm-eabi-gdb $OUT/symbols/system/bin/gdbjithelper
+(gdb) tar r :5039
+Remote debugging using :5039
+Remote debugging from host 127.0.0.1
+gdb: Unable to get location for thread creation breakpoint: requested event is not supported
+__dl__start () at bionic/linker/arch/arm/begin.S:35
+35      mov r0, sp
+gdb: Unable to get location for thread creation breakpoint: requested event is not supported
+Current language:  auto; currently asm
+(gdb) c
+Continuing.
+[New Thread 596]
+codePC[0]: 0x4300e119
+codePC[1]: 0x4284aa7a
+         :
+
+
+Step 4
+
+Hit ctrl-C
+
+Issue the following command to see code around PC
+x /20i (char *) &codePC+1
+
+Issue the following command to see code around LR
+x /20i (char *) &codeLR+1
+

diff --git a/tools/gdbjithelper/gdbjithelper.c b/tools/gdbjithelper/gdbjithelper.c
new file mode 100644 (file)
index 0000000..d0f9ce3
--- /dev/null
+++ b/tools/gdbjithelper/gdbjithelper.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+
+volatile int done;
+
+/*
+ * See README.txt for detailed steps.
+ *
+ * If you see a native crash in the bugreport and the PC/LR are
+ * pointing to the code cache address range, copy them into the following
+ * arrays.
+ *
+ *        #00  pc 463ba204
+ *        #01  lr 463ba1c9  <unknown>
+ *
+ * code around pc:
+ * 463ba1e4 4300e119 4284aa7a f927f7b7 40112268
+ * 463ba1f4 419da7f8 00002000 01000100 00080000
+ * 463ba204 4191debc 01010000 4284aa74 68b00054
+ * 463ba214 045cf205 cc016468 0718f2a5 d0102800
+ * 463ba224 4c13c701 a20aa108 efb0f775 e008e010
+ * 
+ * code around lr:
+ * 463ba1a8 42e19e58 f2050050 cc01045c 0718f2a5
+ * 463ba1b8 d00f2800 4c13c701 a20aa108 efe4f775
+ * 463ba1c8 e007e010 29006bf8 6e77dc01 a10347b8
+ * 463ba1d8 ef60f775 6db1480b 1c2d4788 4300e119
+ * 463ba1e8 4284aa7a f927f7b7 40112268 419da7f8
+ *
+ */
+
+int codePC[] = {
+    // Sample content
+    0x4300e119, 0x4284aa7a, 0xf927f7b7, 0x40112268,
+    0x419da7f8, 0x00002000, 0x01000100, 0x00080000,
+    0x4191debc, 0x01010000, 0x4284aa74, 0x68b00054,
+    0x045cf205, 0xcc016468, 0x0718f2a5, 0xd0102800,
+    0x4c13c701, 0xa20aa108, 0xefb0f775, 0xe008e010,
+};
+
+int codeLR[] = {
+    // Sample content
+    0x42e19e58, 0xf2050050, 0xcc01045c, 0x0718f2a5,
+    0xd00f2800, 0x4c13c701, 0xa20aa108, 0xefe4f775,
+    0xe007e010, 0x29006bf8, 0x6e77dc01, 0xa10347b8,
+    0xef60f775, 0x6db1480b, 0x1c2d4788, 0x4300e119,
+    0x4284aa7a, 0xf927f7b7, 0x40112268, 0x419da7f8,
+};
+
+void dumpCode()
+{
+    unsigned int i;
+
+    for (i = 0; i < sizeof(codePC)/sizeof(int); i++) {
+        printf("codePC[%d]: %#x\n", i, codePC[i]);
+    }
+
+    for (i = 0; i < sizeof(codeLR)/sizeof(int); i++) {
+        printf("codeLR[%d]: %#x\n", i, codeLR[i]);
+    }
+}
+
+int main()
+{
+    dumpCode();
+    while (!done) {
+        sleep(1000);
+    }
+    return 0;
+}