debuggerd: advance our amazing bet.

Remove debuggerd in favor of a helper process that gets execed by
crashing processes.

Bug: http://b/30705528
Test: debuggerd_test
Change-Id: I9906c69473989cbf7fe5ea6cccf9a9c563d75906
diff --git a/debuggerd/crasher/Android.mk b/debuggerd/crasher/Android.mk
new file mode 100644
index 0000000..b8b786b
--- /dev/null
+++ b/debuggerd/crasher/Android.mk
@@ -0,0 +1,66 @@
+LOCAL_PATH := $(call my-dir)
+
+crasher_cppflags := \
+    -std=gnu++14 \
+    -W \
+    -Wall \
+    -Wextra \
+    -Wunused \
+    -Werror \
+    -O0 \
+    -fstack-protector-all \
+    -Wno-free-nonheap-object \
+    -Wno-date-time
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := crasher.cpp
+LOCAL_SRC_FILES_arm    := arm/crashglue.S
+LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
+LOCAL_SRC_FILES_mips   := mips/crashglue.S
+LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
+LOCAL_SRC_FILES_x86    := x86/crashglue.S
+LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
+LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
+LOCAL_MODULE_TAGS := optional
+LOCAL_CPPFLAGS := $(crasher_cppflags)
+LOCAL_SHARED_LIBRARIES := libbase liblog
+
+# The arm emulator has VFP but not VFPv3-D32.
+ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
+LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
+endif
+
+LOCAL_MODULE := crasher
+LOCAL_MODULE_STEM_32 := crasher
+LOCAL_MODULE_STEM_64 := crasher64
+LOCAL_MULTILIB := both
+
+include $(BUILD_EXECUTABLE)
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := crasher.cpp
+LOCAL_SRC_FILES_arm    := arm/crashglue.S
+LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
+LOCAL_SRC_FILES_mips   := mips/crashglue.S
+LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
+LOCAL_SRC_FILES_x86    := x86/crashglue.S
+LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
+LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
+LOCAL_MODULE_TAGS := optional
+LOCAL_CPPFLAGS := $(crasher_cppflags) -DSTATIC_CRASHER
+LOCAL_FORCE_STATIC_EXECUTABLE := true
+LOCAL_SHARED_LIBRARIES := libbase liblog
+
+# The arm emulator has VFP but not VFPv3-D32.
+ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
+LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
+endif
+
+LOCAL_MODULE := static_crasher
+LOCAL_MODULE_STEM_32 := static_crasher
+LOCAL_MODULE_STEM_64 := static_crasher64
+LOCAL_MULTILIB := both
+
+LOCAL_STATIC_LIBRARIES := libdebuggerd_handler libbase liblog
+
+include $(BUILD_EXECUTABLE)
diff --git a/debuggerd/crasher/arm/crashglue.S b/debuggerd/crasher/arm/crashglue.S
new file mode 100644
index 0000000..4fbfd6e
--- /dev/null
+++ b/debuggerd/crasher/arm/crashglue.S
@@ -0,0 +1,64 @@
+.globl crash1
+.type crash1, %function
+crash1:
+	ldr r0, =0xa5a50000
+	ldr r1, =0xa5a50001
+	ldr r2, =0xa5a50002
+	ldr r3, =0xa5a50003
+	ldr r4, =0xa5a50004
+	ldr r5, =0xa5a50005
+	ldr r6, =0xa5a50006
+	ldr r7, =0xa5a50007
+	ldr r8, =0xa5a50008
+	ldr r9, =0xa5a50009
+	ldr r10, =0xa5a50010
+	ldr r11, =0xa5a50011
+	ldr r12, =0xa5a50012
+
+
+	fconstd   d0, #0
+	fconstd   d1, #1
+	fconstd   d2, #2
+	fconstd   d3, #3
+	fconstd   d4, #4
+	fconstd   d5, #5
+	fconstd   d6, #6
+	fconstd   d7, #7
+	fconstd   d8, #8
+	fconstd   d9, #9
+	fconstd   d10, #10
+	fconstd   d11, #11
+	fconstd   d12, #12
+	fconstd   d13, #13
+	fconstd   d14, #14
+	fconstd   d15, #15
+#if defined(HAS_VFP_D32)
+	fconstd   d16, #16
+	fconstd   d17, #17
+	fconstd   d18, #18
+	fconstd   d19, #19
+	fconstd   d20, #20
+	fconstd   d21, #21
+	fconstd   d22, #22
+	fconstd   d23, #23
+	fconstd   d24, #24
+	fconstd   d25, #25
+	fconstd   d26, #26
+	fconstd   d27, #27
+	fconstd   d28, #28
+	fconstd   d29, #29
+	fconstd   d30, #30
+	fconstd   d31, #31
+#endif
+
+	mov lr, #0
+	ldr lr, [lr]
+	b .
+
+.globl crashnostack
+.type crashnostack, %function
+crashnostack:
+	mov sp, #0
+	mov r0, #0
+	ldr r0, [r0]
+	b .
diff --git a/debuggerd/crasher/arm64/crashglue.S b/debuggerd/crasher/arm64/crashglue.S
new file mode 100644
index 0000000..e58b542
--- /dev/null
+++ b/debuggerd/crasher/arm64/crashglue.S
@@ -0,0 +1,79 @@
+.globl crash1
+.type crash1, %function
+crash1:
+	ldr x0, =0xa5a50000
+	ldr x1, =0xa5a50001
+	ldr x2, =0xa5a50002
+	ldr x3, =0xa5a50003
+	ldr x4, =0xa5a50004
+	ldr x5, =0xa5a50005
+	ldr x6, =0xa5a50006
+	ldr x7, =0xa5a50007
+	ldr x8, =0xa5a50008
+	ldr x9, =0xa5a50009
+	ldr x10, =0xa5a50010
+	ldr x11, =0xa5a50011
+	ldr x12, =0xa5a50012
+	ldr x13, =0xa5a50013
+	ldr x14, =0xa5a50014
+	ldr x15, =0xa5a50015
+	ldr x16, =0xa5a50016
+	ldr x17, =0xa5a50017
+	ldr x18, =0xa5a50018
+	ldr x19, =0xa5a50019
+	ldr x20, =0xa5a50020
+	ldr x21, =0xa5a50021
+	ldr x22, =0xa5a50022
+	ldr x23, =0xa5a50023
+	ldr x24, =0xa5a50024
+	ldr x25, =0xa5a50025
+	ldr x26, =0xa5a50026
+	ldr x27, =0xa5a50027
+	ldr x28, =0xa5a50028
+	ldr x29, =0xa5a50029
+
+	fmov   d0, -1.0  // -1 is more convincing than 0.
+	fmov   d1, 1.0
+	fmov   d2, 2.0
+	fmov   d3, 3.0
+	fmov   d4, 4.0
+	fmov   d5, 5.0
+	fmov   d6, 6.0
+	fmov   d7, 7.0
+	fmov   d8, 8.0
+	fmov   d9, 9.0
+	fmov   d10, 10.0
+	fmov   d11, 11.0
+	fmov   d12, 12.0
+	fmov   d13, 13.0
+	fmov   d14, 14.0
+	fmov   d15, 15.0
+	fmov   d16, 16.0
+	fmov   d17, 17.0
+	fmov   d18, 18.0
+	fmov   d19, 19.0
+	fmov   d20, 20.0
+	fmov   d21, 21.0
+	fmov   d22, 22.0
+	fmov   d23, 23.0
+	fmov   d24, 24.0
+	fmov   d25, 25.0
+	fmov   d26, 26.0
+	fmov   d27, 27.0
+	fmov   d28, 28.0
+	fmov   d29, 29.0
+	fmov   d30, 30.0
+	fmov   d31, 31.0
+
+	mov x30, xzr
+	ldr x30, [x30]
+	b .
+
+
+.globl crashnostack
+.type crashnostack, %function
+crashnostack:
+	mov x0, xzr
+	add sp, x0, xzr
+	ldr x0, [x0]
+	b .
diff --git a/debuggerd/crasher/crasher.cpp b/debuggerd/crasher/crasher.cpp
new file mode 100644
index 0000000..288f116
--- /dev/null
+++ b/debuggerd/crasher/crasher.cpp
@@ -0,0 +1,270 @@
+/*
+ * Copyright 2006, 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.
+ */
+
+#define LOG_TAG "crasher"
+
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+// We test both kinds of logging.
+#include <android-base/logging.h>
+#include <log/log.h>
+
+#if defined(STATIC_CRASHER)
+#include "debuggerd/handler.h"
+#endif
+
+#define noinline __attribute__((__noinline__))
+
+// Avoid name mangling so that stacks are more readable.
+extern "C" {
+
+void crash1(void);
+void crashnostack(void);
+
+int do_action(const char* arg);
+
+noinline void maybe_abort() {
+    if (time(0) != 42) {
+        abort();
+    }
+}
+
+char* smash_stack_dummy_buf;
+noinline void smash_stack_dummy_function(volatile int* plen) {
+  smash_stack_dummy_buf[*plen] = 0;
+}
+
+// This must be marked with "__attribute__ ((noinline))", to ensure the
+// compiler generates the proper stack guards around this function.
+// Assign local array address to global variable to force stack guards.
+// Use another noinline function to corrupt the stack.
+noinline int smash_stack(volatile int* plen) {
+    printf("%s: deliberately corrupting stack...\n", getprogname());
+
+    char buf[128];
+    smash_stack_dummy_buf = buf;
+    // This should corrupt stack guards and make process abort.
+    smash_stack_dummy_function(plen);
+    return 0;
+}
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winfinite-recursion"
+
+void* global = 0; // So GCC doesn't optimize the tail recursion out of overflow_stack.
+
+noinline void overflow_stack(void* p) {
+    void* buf[1];
+    buf[0] = p;
+    global = buf;
+    overflow_stack(&buf);
+}
+
+#pragma clang diagnostic pop
+
+noinline void* thread_callback(void* raw_arg) {
+    const char* arg = reinterpret_cast<const char*>(raw_arg);
+    return reinterpret_cast<void*>(static_cast<uintptr_t>(do_action(arg)));
+}
+
+noinline int do_action_on_thread(const char* arg) {
+    pthread_t t;
+    pthread_create(&t, nullptr, thread_callback, const_cast<char*>(arg));
+    void* result = nullptr;
+    pthread_join(t, &result);
+    return reinterpret_cast<uintptr_t>(result);
+}
+
+noinline int crash3(int a) {
+    *reinterpret_cast<int*>(0xdead) = a;
+    return a*4;
+}
+
+noinline int crash2(int a) {
+    a = crash3(a) + 2;
+    return a*3;
+}
+
+noinline int crash(int a) {
+    a = crash2(a) + 1;
+    return a*2;
+}
+
+noinline void abuse_heap() {
+    char buf[16];
+    free(buf); // GCC is smart enough to warn about this, but we're doing it deliberately.
+}
+
+noinline void sigsegv_non_null() {
+    int* a = (int *)(&do_action);
+    *a = 42;
+}
+
+noinline void fprintf_null() {
+    fprintf(nullptr, "oops");
+}
+
+noinline void readdir_null() {
+    readdir(nullptr);
+}
+
+noinline int strlen_null() {
+    char* sneaky_null = nullptr;
+    return strlen(sneaky_null);
+}
+
+static int usage() {
+    fprintf(stderr, "usage: %s KIND\n", getprogname());
+    fprintf(stderr, "\n");
+    fprintf(stderr, "where KIND is:\n");
+    fprintf(stderr, "  smash-stack           overwrite a -fstack-protector guard\n");
+    fprintf(stderr, "  stack-overflow        recurse until the stack overflows\n");
+    fprintf(stderr, "  heap-corruption       cause a libc abort by corrupting the heap\n");
+    fprintf(stderr, "  heap-usage            cause a libc abort by abusing a heap function\n");
+    fprintf(stderr, "  nostack               crash with a NULL stack pointer\n");
+    fprintf(stderr, "  abort                 call abort()\n");
+    fprintf(stderr, "  assert                call assert() without a function\n");
+    fprintf(stderr, "  assert2               call assert() with a function\n");
+    fprintf(stderr, "  exit                  call exit(1)\n");
+    fprintf(stderr, "  fortify               fail a _FORTIFY_SOURCE check\n");
+    fprintf(stderr, "  LOG_ALWAYS_FATAL      call liblog LOG_ALWAYS_FATAL\n");
+    fprintf(stderr, "  LOG_ALWAYS_FATAL_IF   call liblog LOG_ALWAYS_FATAL_IF\n");
+    fprintf(stderr, "  LOG-FATAL             call libbase LOG(FATAL)\n");
+    fprintf(stderr, "  SIGFPE                cause a SIGFPE\n");
+    fprintf(stderr, "  SIGSEGV               cause a SIGSEGV at address 0x0 (synonym: crash)\n");
+    fprintf(stderr, "  SIGSEGV-non-null      cause a SIGSEGV at a non-zero address\n");
+    fprintf(stderr, "  SIGSEGV-unmapped      mmap/munmap a region of memory and then attempt to access it\n");
+    fprintf(stderr, "  SIGTRAP               cause a SIGTRAP\n");
+    fprintf(stderr, "  fprintf-NULL          pass a null pointer to fprintf\n");
+    fprintf(stderr, "  readdir-NULL          pass a null pointer to readdir\n");
+    fprintf(stderr, "  strlen-NULL           pass a null pointer to strlen\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "prefix any of the above with 'thread-' to run on a new thread\n");
+    fprintf(stderr, "prefix any of the above with 'exhaustfd-' to exhaust\n");
+    fprintf(stderr, "all available file descriptors before crashing.\n");
+    fprintf(stderr, "prefix any of the above with 'wait-' to wait until input is received on stdin\n");
+
+    return EXIT_FAILURE;
+}
+
+noinline int do_action(const char* arg) {
+    // Prefixes.
+    if (!strncmp(arg, "wait-", strlen("wait-"))) {
+      char buf[1];
+      TEMP_FAILURE_RETRY(read(STDIN_FILENO, buf, sizeof(buf)));
+      return do_action(arg + strlen("wait-"));
+    } else if (!strncmp(arg, "exhaustfd-", strlen("exhaustfd-"))) {
+      errno = 0;
+      while (errno != EMFILE) {
+        open("/dev/null", O_RDONLY);
+      }
+      return do_action(arg + strlen("exhaustfd-"));
+    } else if (!strncmp(arg, "thread-", strlen("thread-"))) {
+        return do_action_on_thread(arg + strlen("thread-"));
+    }
+
+    // Actions.
+    if (!strcasecmp(arg, "SIGSEGV-non-null")) {
+        sigsegv_non_null();
+    } else if (!strcasecmp(arg, "smash-stack")) {
+        volatile int len = 128;
+        return smash_stack(&len);
+    } else if (!strcasecmp(arg, "stack-overflow")) {
+        overflow_stack(nullptr);
+    } else if (!strcasecmp(arg, "nostack")) {
+        crashnostack();
+    } else if (!strcasecmp(arg, "exit")) {
+        exit(1);
+    } else if (!strcasecmp(arg, "crash") || !strcmp(arg, "SIGSEGV")) {
+        return crash(42);
+    } else if (!strcasecmp(arg, "abort")) {
+        maybe_abort();
+    } else if (!strcasecmp(arg, "assert")) {
+        __assert("some_file.c", 123, "false");
+    } else if (!strcasecmp(arg, "assert2")) {
+        __assert2("some_file.c", 123, "some_function", "false");
+    } else if (!strcasecmp(arg, "fortify")) {
+        char buf[10];
+        __read_chk(-1, buf, 32, 10);
+        while (true) pause();
+    } else if (!strcasecmp(arg, "LOG(FATAL)")) {
+        LOG(FATAL) << "hello " << 123;
+    } else if (!strcasecmp(arg, "LOG_ALWAYS_FATAL")) {
+        LOG_ALWAYS_FATAL("hello %s", "world");
+    } else if (!strcasecmp(arg, "LOG_ALWAYS_FATAL_IF")) {
+        LOG_ALWAYS_FATAL_IF(true, "hello %s", "world");
+    } else if (!strcasecmp(arg, "SIGFPE")) {
+        raise(SIGFPE);
+        return EXIT_SUCCESS;
+    } else if (!strcasecmp(arg, "SIGTRAP")) {
+        raise(SIGTRAP);
+        return EXIT_SUCCESS;
+    } else if (!strcasecmp(arg, "fprintf-NULL")) {
+        fprintf_null();
+    } else if (!strcasecmp(arg, "readdir-NULL")) {
+        readdir_null();
+    } else if (!strcasecmp(arg, "strlen-NULL")) {
+        return strlen_null();
+    } else if (!strcasecmp(arg, "heap-usage")) {
+        abuse_heap();
+    } else if (!strcasecmp(arg, "SIGSEGV-unmapped")) {
+        char* map = reinterpret_cast<char*>(mmap(nullptr, sizeof(int), PROT_READ | PROT_WRITE,
+                                                 MAP_SHARED | MAP_ANONYMOUS, -1, 0));
+        munmap(map, sizeof(int));
+        map[0] = '8';
+    } else {
+        return usage();
+    }
+
+    fprintf(stderr, "%s: exiting normally!\n", getprogname());
+    return EXIT_SUCCESS;
+}
+
+int main(int argc, char** argv) {
+#if defined(STATIC_CRASHER)
+    debuggerd_callbacks_t callbacks = {
+      .get_abort_message = []() {
+        static struct {
+          size_t size;
+          char msg[32];
+        } msg;
+
+        msg.size = strlen("dummy abort message");
+        memcpy(msg.msg, "dummy abort message", strlen("dummy abort message"));
+        return reinterpret_cast<abort_msg_t*>(&msg);
+      },
+      .post_dump = nullptr
+    };
+    debuggerd_init(&callbacks);
+#endif
+
+    if (argc == 1) crash1();
+    else if (argc == 2) return do_action(argv[1]);
+
+    return usage();
+}
+
+};
diff --git a/debuggerd/crasher/mips/crashglue.S b/debuggerd/crasher/mips/crashglue.S
new file mode 100644
index 0000000..70a6641
--- /dev/null
+++ b/debuggerd/crasher/mips/crashglue.S
@@ -0,0 +1,48 @@
+	.set	noat
+
+	.globl crash1
+	.globl crashnostack
+
+crash1:
+	li	$0,0xdead0000+0
+	li	$1,0xdead0000+1
+	li	$2,0xdead0000+2
+	li	$3,0xdead0000+3
+	li	$4,0xdead0000+4
+	li	$5,0xdead0000+5
+	li	$6,0xdead0000+6
+	li	$7,0xdead0000+7
+	li	$8,0xdead0000+8
+	li	$9,0xdead0000+9
+	li	$10,0xdead0000+10
+	li	$11,0xdead0000+11
+	li	$12,0xdead0000+12
+	li	$13,0xdead0000+13
+	li	$14,0xdead0000+14
+	li	$15,0xdead0000+15
+	li	$16,0xdead0000+16
+	li	$17,0xdead0000+17
+	li	$18,0xdead0000+18
+	li	$19,0xdead0000+19
+	li	$20,0xdead0000+20
+	li	$21,0xdead0000+21
+	li	$22,0xdead0000+22
+	li	$23,0xdead0000+23
+	li	$24,0xdead0000+24
+	li	$25,0xdead0000+25
+	li	$26,0xdead0000+26
+	li	$27,0xdead0000+27
+	li	$28,0xdead0000+28
+	# don't trash the stack otherwise the signal handler won't run
+	#li	$29,0xdead0000+29
+	li	$30,0xdead0000+30
+	li	$31,0xdead0000+31
+
+	lw	$zero,($0)
+	b .
+
+
+crashnostack:
+	li	$sp, 0
+	lw	$zero,($0)
+	b .
diff --git a/debuggerd/crasher/mips64/crashglue.S b/debuggerd/crasher/mips64/crashglue.S
new file mode 100644
index 0000000..70a6641
--- /dev/null
+++ b/debuggerd/crasher/mips64/crashglue.S
@@ -0,0 +1,48 @@
+	.set	noat
+
+	.globl crash1
+	.globl crashnostack
+
+crash1:
+	li	$0,0xdead0000+0
+	li	$1,0xdead0000+1
+	li	$2,0xdead0000+2
+	li	$3,0xdead0000+3
+	li	$4,0xdead0000+4
+	li	$5,0xdead0000+5
+	li	$6,0xdead0000+6
+	li	$7,0xdead0000+7
+	li	$8,0xdead0000+8
+	li	$9,0xdead0000+9
+	li	$10,0xdead0000+10
+	li	$11,0xdead0000+11
+	li	$12,0xdead0000+12
+	li	$13,0xdead0000+13
+	li	$14,0xdead0000+14
+	li	$15,0xdead0000+15
+	li	$16,0xdead0000+16
+	li	$17,0xdead0000+17
+	li	$18,0xdead0000+18
+	li	$19,0xdead0000+19
+	li	$20,0xdead0000+20
+	li	$21,0xdead0000+21
+	li	$22,0xdead0000+22
+	li	$23,0xdead0000+23
+	li	$24,0xdead0000+24
+	li	$25,0xdead0000+25
+	li	$26,0xdead0000+26
+	li	$27,0xdead0000+27
+	li	$28,0xdead0000+28
+	# don't trash the stack otherwise the signal handler won't run
+	#li	$29,0xdead0000+29
+	li	$30,0xdead0000+30
+	li	$31,0xdead0000+31
+
+	lw	$zero,($0)
+	b .
+
+
+crashnostack:
+	li	$sp, 0
+	lw	$zero,($0)
+	b .
diff --git a/debuggerd/crasher/x86/crashglue.S b/debuggerd/crasher/x86/crashglue.S
new file mode 100644
index 0000000..59df432
--- /dev/null
+++ b/debuggerd/crasher/x86/crashglue.S
@@ -0,0 +1,15 @@
+.globl crash1
+.globl crashnostack
+
+crash1:
+	movl $0xa5a50000, %eax
+	movl $0xa5a50001, %ebx
+	movl $0xa5a50002, %ecx
+
+	movl $0, %edx
+	jmp *%edx
+
+
+crashnostack:
+	movl $0, %ebp
+	jmp *%ebp
diff --git a/debuggerd/crasher/x86_64/crashglue.S b/debuggerd/crasher/x86_64/crashglue.S
new file mode 100644
index 0000000..4d2a5c0
--- /dev/null
+++ b/debuggerd/crasher/x86_64/crashglue.S
@@ -0,0 +1,15 @@
+.globl crash1
+.globl crashnostack
+
+crash1:
+	movl $0xa5a50000, %eax
+	movl $0xa5a50001, %ebx
+	movl $0xa5a50002, %ecx
+
+	movl $0, %edx
+	jmp *%rdx
+
+
+crashnostack:
+	movl $0, %ebp
+	jmp *%rbp