am 50fae736: am 1f71e465: am 68870199: Merge "Next phase of the move, reformat use C++ features." (8791ee5c) · Commits · e / os / android_system_core

debuggerd/arm/machine.cpp

+133 −140

Original line number	Diff line number	Diff line
		/* system/debuggerd/debuggerd.c
		**
		** 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.
		/*
		*
		* 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.
		*/

		#include <errno.h>
		#include <stdbool.h>
		#include <stddef.h>
		#include <stdio.h>
		#include <stdlib.h>
		@@ -28,7 +27,7 @@
		#include "../utility.h"
		#include "../machine.h"

		/* enable to dump memory pointed to by every register */
		// enable to dump memory pointed to by every register
		#define DUMP_MEMORY_FOR_ALL_REGISTERS 1

		#ifdef WITH_VFP
		@@ -40,27 +39,26 @@
		#endif

		static void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags) {
		char code_buffer[64]; /* actual 8+1+((8+1)4) + 1 == 45 /
		char ascii_buffer[32]; /* actual 16 + 1 == 17 */
		char code_buffer[64]; // actual 8+1+((8+1)*4) + 1 == 45
		char ascii_buffer[32]; // actual 16 + 1 == 17
		uintptr_t p, end;

		p = addr & ~3;
		p -= 32;
		if (p > addr) {
		/* catch underflow */
		// catch underflow
		p = 0;
		}
		/* Dump more memory content for the crashing thread. */
		// Dump more memory content for the crashing thread.
		end = p + 256;
		/* catch overflow; 'end - p' has to be multiples of 16 */
		// catch overflow; 'end - p' has to be multiples of 16
		while (end < p)
		end -= 16;

		/* Dump the code around PC as:
		* addr contents ascii
		* 00008d34 ef000000 e8bd0090 e1b00000 512fff1e ............../Q
		* 00008d44 ea00b1f9 e92d0090 e3a070fc ef000000 ......-..p......
		*/
		// Dump the code around PC as:
		// addr contents ascii
		// 00008d34 ef000000 e8bd0090 e1b00000 512fff1e ............../Q
		// 00008d44 ea00b1f9 e92d0090 e3a070fc ef000000 ......-..p......
		while (p < end) {
		char* asc_out = ascii_buffer;

		@@ -68,26 +66,22 @@ static void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags)

		int i;
		for (i = 0; i < 4; i++) {
		/*
		* If we see (data == -1 && errno != 0), we know that the ptrace
		* call failed, probably because we're dumping memory in an
		* unmapped or inaccessible page. I don't know if there's
		* value in making that explicit in the output -- it likely
		* just complicates parsing and clarifies nothing for the
		* enlightened reader.
		*/
		long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL);
		// If we see (data == -1 && errno != 0), we know that the ptrace
		// call failed, probably because we're dumping memory in an
		// unmapped or inaccessible page. I don't know if there's
		// value in making that explicit in the output -- it likely
		// just complicates parsing and clarifies nothing for the
		// enlightened reader.
		long data = ptrace(PTRACE_PEEKTEXT, tid, reinterpret_cast<void*>(p), NULL);
		sprintf(code_buffer + strlen(code_buffer), "%08lx ", data);

		/* Enable the following code blob to dump ASCII values */
		// Enable the following code blob to dump ASCII values
		#if 0
		int j;
		for (j = 0; j < 4; j++) {
		/*
		* Our isprint() allows high-ASCII characters that display
		* differently (often badly) in different viewers, so we
		* just use a simpler test.
		*/
		// Our isprint() allows high-ASCII characters that display
		// differently (often badly) in different viewers, so we
		// just use a simpler test.
		char val = (data >> (j*8)) & 0xff;
		if (val >= 0x20 && val < 0x7f) {
		*asc_out++ = val;
		@@ -103,10 +97,8 @@ static void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags)
		}
		}

		/*
		* If configured to do so, dump memory around all registers
		* for the crashing thread.
		*/
		// If configured to do so, dump memory around all registers
		// for the crashing thread.
		void dump_memory_and_code(log_t* log, pid_t tid, int scope_flags) {
		struct pt_regs regs;
		if (ptrace(PTRACE_GETREGS, tid, 0, &regs)) {
		@@ -117,13 +109,11 @@ void dump_memory_and_code(log_t* log, pid_t tid, int scope_flags) {
		static const char REG_NAMES[] = "r0r1r2r3r4r5r6r7r8r9slfpipsp";

		for (int reg = 0; reg < 14; reg++) {
		/* this may not be a valid way to access, but it'll do for now */
		// this may not be a valid way to access, but it'll do for now
		uintptr_t addr = regs.uregs[reg];

		/*
		* Don't bother if it looks like a small int or ~= null, or if
		* it's in the kernel area.
		*/
		// Don't bother if it looks like a small int or ~= null, or if
		// it's in the kernel area.
		if (addr < 4096 \|\| addr >= 0xc0000000) {
		continue;
		}
		@@ -133,18 +123,17 @@ void dump_memory_and_code(log_t* log, pid_t tid, int scope_flags) {
		}
		}

		/* explicitly allow upload of code dump logging */
		// explicitly allow upload of code dump logging
		_LOG(log, scope_flags, "\ncode around pc:\n");
		dump_memory(log, tid, (uintptr_t)regs.ARM_pc, scope_flags);
		dump_memory(log, tid, static_cast<uintptr_t>(regs.ARM_pc), scope_flags);

		if (regs.ARM_pc != regs.ARM_lr) {
		_LOG(log, scope_flags, "\ncode around lr:\n");
		dump_memory(log, tid, (uintptr_t)regs.ARM_lr, scope_flags);
		dump_memory(log, tid, static_cast<uintptr_t>(regs.ARM_lr), scope_flags);
		}
		}

		void dump_registers(log_t* log, pid_t tid, int scope_flags)
		{
		void dump_registers(log_t* log, pid_t tid, int scope_flags) {
		struct pt_regs r;
		if (ptrace(PTRACE_GETREGS, tid, 0, &r)) {
		_LOG(log, scope_flags, "cannot get registers: %s\n", strerror(errno));
		@@ -152,14 +141,18 @@ void dump_registers(log_t* log, pid_t tid, int scope_flags)
		}

		_LOG(log, scope_flags, " r0 %08x r1 %08x r2 %08x r3 %08x\n",
		(uint32_t)r.ARM_r0, (uint32_t)r.ARM_r1, (uint32_t)r.ARM_r2, (uint32_t)r.ARM_r3);
		static_cast<uint32_t>(r.ARM_r0), static_cast<uint32_t>(r.ARM_r1),
		static_cast<uint32_t>(r.ARM_r2), static_cast<uint32_t>(r.ARM_r3));
		_LOG(log, scope_flags, " r4 %08x r5 %08x r6 %08x r7 %08x\n",
		(uint32_t)r.ARM_r4, (uint32_t)r.ARM_r5, (uint32_t)r.ARM_r6, (uint32_t)r.ARM_r7);
		static_cast<uint32_t>(r.ARM_r4), static_cast<uint32_t>(r.ARM_r5),
		static_cast<uint32_t>(r.ARM_r6), static_cast<uint32_t>(r.ARM_r7));
		_LOG(log, scope_flags, " r8 %08x r9 %08x sl %08x fp %08x\n",
		(uint32_t)r.ARM_r8, (uint32_t)r.ARM_r9, (uint32_t)r.ARM_r10, (uint32_t)r.ARM_fp);
		static_cast<uint32_t>(r.ARM_r8), static_cast<uint32_t>(r.ARM_r9),
		static_cast<uint32_t>(r.ARM_r10), static_cast<uint32_t>(r.ARM_fp));
		_LOG(log, scope_flags, " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n",
		(uint32_t)r.ARM_ip, (uint32_t)r.ARM_sp, (uint32_t)r.ARM_lr,
		(uint32_t)r.ARM_pc, (uint32_t)r.ARM_cpsr);
		static_cast<uint32_t>(r.ARM_ip), static_cast<uint32_t>(r.ARM_sp),
		static_cast<uint32_t>(r.ARM_lr), static_cast<uint32_t>(r.ARM_pc),
		static_cast<uint32_t>(r.ARM_cpsr));

		#ifdef WITH_VFP
		struct user_vfp vfp_regs;

debuggerd/backtrace.cpp

+88 −94

Original line number	Diff line number	Diff line
		@@ -15,7 +15,6 @@
		*/

		#include <stddef.h>
		#include <stdbool.h>
		#include <stdlib.h>
		#include <string.h>
		#include <stdio.h>
		@@ -27,7 +26,8 @@
		#include <sys/types.h>
		#include <sys/ptrace.h>

		#include <backtrace/backtrace.h>
		#include <backtrace/Backtrace.h>
		#include <UniquePtr.h>

		#include "backtrace.h"
		#include "utility.h"
		@@ -60,8 +60,8 @@ static void dump_process_footer(log_t* log, pid_t pid) {
		_LOG(log, SCOPE_AT_FAULT, "\n----- end %d -----\n", pid);
		}

		static void dump_thread(log_t* log, pid_t tid, bool attached,
		bool* detach_failed, int* total_sleep_time_usec) {
		static void dump_thread(
		log_t* log, pid_t tid, bool attached, bool* detach_failed, int* total_sleep_time_usec) {
		char path[PATH_MAX];
		char threadnamebuf[1024];
		char* threadname = NULL;
		@@ -79,8 +79,7 @@ static void dump_thread(log_t* log, pid_t tid, bool attached,
		}
		}

		_LOG(log, SCOPE_AT_FAULT, "\n\"%s\" sysTid=%d\n",
		threadname ? threadname : "<unknown>", tid);
		_LOG(log, SCOPE_AT_FAULT, "\n\"%s\" sysTid=%d\n", threadname ? threadname : "<unknown>", tid);

		if (!attached && ptrace(PTRACE_ATTACH, tid, 0, 0) < 0) {
		_LOG(log, SCOPE_AT_FAULT, "Could not attach to thread: %s\n", strerror(errno));
		@@ -89,12 +88,9 @@ static void dump_thread(log_t* log, pid_t tid, bool attached,

		wait_for_stop(tid, total_sleep_time_usec);

		backtrace_context_t context;
		if (!backtrace_create_context(&context, tid, -1, 0)) {
		_LOG(log, SCOPE_AT_FAULT, "Could not create backtrace context.\n");
		} else {
		dump_backtrace_to_log(&context, log, SCOPE_AT_FAULT, " ");
		backtrace_destroy_context(&context);
		UniquePtr<Backtrace> backtrace(Backtrace::Create(tid, BACKTRACE_CURRENT_THREAD));
		if (backtrace->Unwind(0)) {
		dump_backtrace_to_log(backtrace.get(), log, SCOPE_AT_FAULT, " ");
		}

		if (!attached && ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
		@@ -137,11 +133,9 @@ void dump_backtrace(int fd, int amfd, pid_t pid, pid_t tid, bool* detach_failed,
		dump_process_footer(&log, pid);
		}

		void dump_backtrace_to_log(const backtrace_context_t* context, log_t* log,
		void dump_backtrace_to_log(Backtrace* backtrace, log_t* log,
		int scope_flags, const char* prefix) {
		char buf[512];
		for (size_t i = 0; i < context->backtrace->num_frames; i++) {
		backtrace_format_frame_data(context, i, buf, sizeof(buf));
		_LOG(log, scope_flags, "%s%s\n", prefix, buf);
		for (size_t i = 0; i < backtrace->NumFrames(); i++) {
		_LOG(log, scope_flags, "%s%s\n", prefix, backtrace->FormatFrameData(i).c_str());
		}
		}

debuggerd/backtrace.h

+7 −9

Original line number	Diff line number	Diff line
		@@ -17,21 +17,19 @@
		#ifndef _DEBUGGERD_BACKTRACE_H
		#define _DEBUGGERD_BACKTRACE_H

		#include <stddef.h>
		#include <stdbool.h>
		#include <sys/types.h>

		#include <backtrace/backtrace.h>

		#include "utility.h"

		/* Dumps a backtrace using a format similar to what Dalvik uses so that the result
		* can be intermixed in a bug report. */
		class Backtrace;

		// Dumps a backtrace using a format similar to what Dalvik uses so that the result
		// can be intermixed in a bug report.
		void dump_backtrace(int fd, int amfd, pid_t pid, pid_t tid, bool* detach_failed,
		int* total_sleep_time_usec);

		/* Dumps the backtrace in the backtrace data structure to the log. */
		void dump_backtrace_to_log(const backtrace_context_t* context, log_t* log,
		void dump_backtrace_to_log(Backtrace* backtrace, log_t* log,
		int scope_flags, const char* prefix);

		#endif // _DEBUGGERD_BACKTRACE_H

debuggerd/debuggerd.cpp

+422 −447

Original line number	Diff line number	Diff line
		/* system/debuggerd/debuggerd.c
		**
		** 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.
		/*
		* 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.
		*/

		#include <stdio.h>
		@@ -38,8 +37,6 @@
		#include <cutils/properties.h>
		#include <cutils/debugger.h>

		#include <corkscrew/backtrace.h>

		#include <linux/input.h>

		#include <private/android_filesystem_config.h>
		@@ -56,9 +53,7 @@ typedef struct {
		uintptr_t abort_msg_address;
		} debugger_request_t;

		static int
		write_string(const char* file, const char* string)
		{
		static int write_string(const char* file, const char* string) {
		int len;
		int fd;
		ssize_t amt;
		@@ -71,9 +66,7 @@ write_string(const char* file, const char* string)
		return amt >= 0 ? 0 : -errno;
		}

		static
		void init_debug_led(void)
		{
		static void init_debug_led() {
		// trout leds
		write_string("/sys/class/leds/red/brightness", "0");
		write_string("/sys/class/leds/green/brightness", "0");
		@@ -83,18 +76,14 @@ void init_debug_led(void)
		write_string("/sys/class/leds/left/cadence", "0,0");
		}

		static
		void enable_debug_led(void)
		{
		static void enable_debug_led() {
		// trout leds
		write_string("/sys/class/leds/red/brightness", "255");
		// sardine leds
		write_string("/sys/class/leds/left/cadence", "1,0");
		}

		static
		void disable_debug_led(void)
		{
		static void disable_debug_led() {
		// trout leds
		write_string("/sys/class/leds/red/brightness", "0");
		// sardine leds
		@@ -102,7 +91,7 @@ void disable_debug_led(void)
		}

		static void wait_for_user_action(pid_t pid) {
		/* First log a helpful message */
		// First log a helpful message
		LOG( "********************************************************\n"
		"* Process %d has been suspended while crashing. To\n"
		"* attach gdbserver for a gdb connection on port 5039\n"
		@@ -115,7 +104,7 @@ static void wait_for_user_action(pid_t pid) {
		"********************************************************\n",
		pid, pid);

		/* wait for HOME or VOLUME DOWN key */
		// wait for HOME or VOLUME DOWN key
		if (init_getevent() == 0) {
		int ms = 1200 / 10;
		int dit = 1;
		@@ -153,7 +142,7 @@ static void wait_for_user_action(pid_t pid) {
		uninit_getevent();
		}

		/* don't forget to turn debug led off */
		// don't forget to turn debug led off
		disable_debug_led();
		LOG("debuggerd resuming process %d", pid);
		}
		@@ -212,15 +201,13 @@ static int read_request(int fd, debugger_request_t* out_request) {
		memset(&msg, 0, sizeof(msg));
		status = TEMP_FAILURE_RETRY(read(fd, &msg, sizeof(msg)));
		if (status < 0) {
		LOG("read failure? %s (pid=%d uid=%d)\n",
		strerror(errno), cr.pid, cr.uid);
		LOG("read failure? %s (pid=%d uid=%d)\n", strerror(errno), cr.pid, cr.uid);
		return -1;
		}
		if (status == sizeof(debugger_msg_t)) {
		XLOG("crash request of size %d abort_msg_address=%#08x\n", status, msg.abort_msg_address);
		} else {
		LOG("invalid crash request of size %d (from pid=%d uid=%d)\n",
		status, cr.pid, cr.uid);
		LOG("invalid crash request of size %d (from pid=%d uid=%d)\n", status, cr.pid, cr.uid);
		return -1;
		}

		@@ -232,7 +219,7 @@ static int read_request(int fd, debugger_request_t* out_request) {
		out_request->abort_msg_address = msg.abort_msg_address;

		if (msg.action == DEBUGGER_ACTION_CRASH) {
		/* Ensure that the tid reported by the crashing process is valid. */
		// Ensure that the tid reported by the crashing process is valid.
		char buf[64];
		struct stat s;
		snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
		@@ -243,17 +230,16 @@ static int read_request(int fd, debugger_request_t* out_request) {
		}
		} else if (cr.uid == 0
		\|\| (cr.uid == AID_SYSTEM && msg.action == DEBUGGER_ACTION_DUMP_BACKTRACE)) {
		/* Only root or system can ask us to attach to any process and dump it explicitly.
		* However, system is only allowed to collect backtraces but cannot dump tombstones. */
		// Only root or system can ask us to attach to any process and dump it explicitly.
		// However, system is only allowed to collect backtraces but cannot dump tombstones.
		status = get_process_info(out_request->tid, &out_request->pid,
		&out_request->uid, &out_request->gid);
		if (status < 0) {
		LOG("tid %d does not exist. ignoring explicit dump request\n",
		out_request->tid);
		LOG("tid %d does not exist. ignoring explicit dump request\n", out_request->tid);
		return -1;
		}
		} else {
		/* No one else is allowed to dump arbitrary processes. */
		// No one else is allowed to dump arbitrary processes.
		return -1;
		}
		return 0;
		@@ -279,17 +265,16 @@ static void handle_request(int fd) {
		XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n",
		request.pid, request.uid, request.gid, request.tid);

		/* At this point, the thread that made the request is blocked in
		* a read() call. If the thread has crashed, then this gives us
		* time to PTRACE_ATTACH to it before it has a chance to really fault.
		*
		* The PTRACE_ATTACH sends a SIGSTOP to the target process, but it
		* won't necessarily have stopped by the time ptrace() returns. (We
		* currently assume it does.) We write to the file descriptor to
		* ensure that it can run as soon as we call PTRACE_CONT below.
		* See details in bionic/libc/linker/debugger.c, in function
		* debugger_signal_handler().
		*/
		// At this point, the thread that made the request is blocked in
		// a read() call. If the thread has crashed, then this gives us
		// time to PTRACE_ATTACH to it before it has a chance to really fault.
		//
		// The PTRACE_ATTACH sends a SIGSTOP to the target process, but it
		// won't necessarily have stopped by the time ptrace() returns. (We
		// currently assume it does.) We write to the file descriptor to
		// ensure that it can run as soon as we call PTRACE_CONT below.
		// See details in bionic/libc/linker/debugger.c, in function
		// debugger_signal_handler().
		if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
		LOG("ptrace attach failed: %s\n", strerror(errno));
		} else {
		@@ -316,13 +301,12 @@ static void handle_request(int fd) {
		case SIGSTOP:
		if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
		XLOG("stopped -- dumping to tombstone\n");
		tombstone_path = engrave_tombstone(request.pid, request.tid,
		signal, request.abort_msg_address, true, true, &detach_failed,
		&total_sleep_time_usec);
		tombstone_path = engrave_tombstone(
		request.pid, request.tid, signal, request.abort_msg_address, true, true,
		&detach_failed, &total_sleep_time_usec);
		} else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
		XLOG("stopped -- dumping to fd\n");
		dump_backtrace(fd, -1,
		request.pid, request.tid, &detach_failed,
		dump_backtrace(fd, -1, request.pid, request.tid, &detach_failed,
		&total_sleep_time_usec);
		} else {
		XLOG("stopped -- continuing\n");
		@@ -330,7 +314,7 @@ static void handle_request(int fd) {
		if (status) {
		LOG("ptrace continue failed: %s\n", strerror(errno));
		}
		continue; /* loop again */
		continue; // loop again
		}
		break;

		@@ -343,22 +327,18 @@ static void handle_request(int fd) {
		#ifdef SIGSTKFLT
		case SIGSTKFLT:
		#endif
		{
		XLOG("stopped -- fatal signal\n");
		/*
		* Send a SIGSTOP to the process to make all of
		* the non-signaled threads stop moving. Without
		* this we get a lot of "ptrace detach failed:
		* No such process".
		*/
		// Send a SIGSTOP to the process to make all of
		// the non-signaled threads stop moving. Without
		// this we get a lot of "ptrace detach failed:
		// No such process".
		kill(request.pid, SIGSTOP);
		/* don't dump sibling threads when attaching to GDB because it
		* makes the process less reliable, apparently... */
		tombstone_path = engrave_tombstone(request.pid, request.tid,
		signal, request.abort_msg_address, !attach_gdb, false,
		&detach_failed, &total_sleep_time_usec);
		// don't dump sibling threads when attaching to GDB because it
		// makes the process less reliable, apparently...
		tombstone_path = engrave_tombstone(
		request.pid, request.tid, signal, request.abort_msg_address, !attach_gdb,
		false, &detach_failed, &total_sleep_time_usec);
		break;
		}

		default:
		XLOG("stopped -- unexpected signal\n");
		@@ -380,36 +360,34 @@ static void handle_request(int fd) {

		XLOG("detaching\n");
		if (attach_gdb) {
		/* stop the process so we can debug */
		// stop the process so we can debug
		kill(request.pid, SIGSTOP);

		/* detach so we can attach gdbserver */
		// detach so we can attach gdbserver
		if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
		LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
		detach_failed = true;
		}

		/*
		* if debug.db.uid is set, its value indicates if we should wait
		* for user action for the crashing process.
		* in this case, we log a message and turn the debug LED on
		* waiting for a gdb connection (for instance)
		*/
		// if debug.db.uid is set, its value indicates if we should wait
		// for user action for the crashing process.
		// in this case, we log a message and turn the debug LED on
		// waiting for a gdb connection (for instance)
		wait_for_user_action(request.pid);
		} else {
		/* just detach */
		// just detach
		if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
		LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
		detach_failed = true;
		}
		}

		/* resume stopped process (so it can crash in peace). */
		// resume stopped process (so it can crash in peace).
		kill(request.pid, SIGCONT);

		/* If we didn't successfully detach, we're still the parent, and the
		* actual parent won't receive a death notification via wait(2). At this point
		* there's not much we can do about that. */
		// If we didn't successfully detach, we're still the parent, and the
		// actual parent won't receive a death notification via wait(2). At this point
		// there's not much we can do about that.
		if (detach_failed) {
		LOG("debuggerd committing suicide to free the zombie!\n");
		kill(getpid(), SIGKILL);
		@@ -427,10 +405,8 @@ static int do_server() {
		struct sigaction act;
		int logsocket = -1;

		/*
		* debuggerd crashes can't be reported to debuggerd. Reset all of the
		* crash handlers.
		*/
		// debuggerd crashes can't be reported to debuggerd. Reset all of the
		// crash handlers.
		signal(SIGILL, SIG_DFL);
		signal(SIGABRT, SIG_DFL);
		signal(SIGBUS, SIG_DFL);
		@@ -443,8 +419,7 @@ static int do_server() {
		// Ignore failed writes to closed sockets
		signal(SIGPIPE, SIG_IGN);

		logsocket = socket_local_client("logd",
		ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
		logsocket = socket_local_client("logd", ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
		if (logsocket < 0) {
		logsocket = -1;
		} else {
		@@ -457,9 +432,9 @@ static int do_server() {
		act.sa_flags = SA_NOCLDWAIT;
		sigaction(SIGCHLD, &act, 0);

		s = socket_local_server(DEBUGGER_SOCKET_NAME,
		ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_STREAM);
		if(s < 0) return 1;
		s = socket_local_server(DEBUGGER_SOCKET_NAME, ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_STREAM);
		if (s < 0)
		return 1;
		fcntl(s, F_SETFD, FD_CLOEXEC);

		LOG("debuggerd: " __DATE__ " " __TIME__ "\n");