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Anonymous committed d607495

Move to C++ for debuggerd.

This is part 1, only including the bare minimum changes because
our diff tool doesn't easily show differences when a file moves. This
also breaks it into a small chunk in case some other changes break things,
as unlikely as I think that will be.

Change-Id: Ib7a3e7a2cc1ac574d15b65fda23813ebcf5d31af

  • Participants
  • Parent commits 261ff50

Comments (0)

Files changed (17)

debuggerd/Android.mk

 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= \
-	backtrace.c \
-	debuggerd.c \
-	getevent.c \
-	tombstone.c \
-	utility.c \
-	$(TARGET_ARCH)/machine.c
-
-LOCAL_CFLAGS := -Wall -Wno-unused-parameter -std=gnu99
+	backtrace.cpp \
+	debuggerd.cpp \
+	getevent.cpp \
+	tombstone.cpp \
+	utility.cpp \
+	$(TARGET_ARCH)/machine.cpp \
+
+LOCAL_CONLYFLAGS := -std=gnu99
+LOCAL_CPPFLAGS := -std=gnu++11
+LOCAL_CFLAGS := \
+	-Wall \
+	-Wno-array-bounds \
+	-Werror \
+
 LOCAL_MODULE := debuggerd
 
 ifeq ($(ARCH_ARM_HAVE_VFP),true)
 	liblog \
 	libselinux \
 
+include external/stlport/libstlport.mk
+
 include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := crasher
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := optional
-LOCAL_CFLAGS += -fstack-protector-all
+LOCAL_CFLAGS += -fstack-protector-all -Wno-unused-parameter -Wno-free-nonheap-object
 #LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_SHARED_LIBRARIES := libcutils liblog libc
 include $(BUILD_EXECUTABLE)

debuggerd/arm/machine.c

-/* 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.
-*/
-
-#include <errno.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/ptrace.h>
-#include <sys/types.h>
-#include <sys/user.h>
-
-#include "../utility.h"
-#include "../machine.h"
-
-/* enable to dump memory pointed to by every register */
-#define DUMP_MEMORY_FOR_ALL_REGISTERS 1
-
-#ifdef WITH_VFP
-#ifdef WITH_VFP_D32
-#define NUM_VFP_REGS 32
-#else
-#define NUM_VFP_REGS 16
-#endif
-#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 */
-    uintptr_t p, end;
-
-    p = addr & ~3;
-    p -= 32;
-    if (p > addr) {
-        /* catch underflow */
-        p = 0;
-    }
-    /* Dump more memory content for the crashing thread. */
-    end = p + 256;
-    /* 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......
-     */
-    while (p < end) {
-        char* asc_out = ascii_buffer;
-
-        sprintf(code_buffer, "%08x ", p);
-
-        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);
-            sprintf(code_buffer + strlen(code_buffer), "%08lx ", data);
-
-            /* 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.
-                 */
-                char val = (data >> (j*8)) & 0xff;
-                if (val >= 0x20 && val < 0x7f) {
-                    *asc_out++ = val;
-                } else {
-                    *asc_out++ = '.';
-                }
-            }
-#endif
-            p += 4;
-        }
-        *asc_out = '\0';
-        _LOG(log, scope_flags, "    %s %s\n", code_buffer, ascii_buffer);
-    }
-}
-
-/*
- * 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)) {
-        return;
-    }
-
-    if (IS_AT_FAULT(scope_flags) && DUMP_MEMORY_FOR_ALL_REGISTERS) {
-        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 */
-            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.
-             */
-            if (addr < 4096 || addr >= 0xc0000000) {
-                continue;
-            }
-
-            _LOG(log, scope_flags | SCOPE_SENSITIVE, "\nmemory near %.2s:\n", &REG_NAMES[reg * 2]);
-            dump_memory(log, tid, addr, scope_flags | SCOPE_SENSITIVE);
-        }
-    }
-
-    /* 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);
-
-    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);
-    }
-}
-
-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));
-        return;
-    }
-
-    _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);
-    _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);
-    _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);
-    _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);
-
-#ifdef WITH_VFP
-    struct user_vfp vfp_regs;
-    int i;
-
-    if(ptrace(PTRACE_GETVFPREGS, tid, 0, &vfp_regs)) {
-        _LOG(log, scope_flags, "cannot get registers: %s\n", strerror(errno));
-        return;
-    }
-
-    for (i = 0; i < NUM_VFP_REGS; i += 2) {
-        _LOG(log, scope_flags, "    d%-2d %016llx  d%-2d %016llx\n",
-                i, vfp_regs.fpregs[i], i+1, vfp_regs.fpregs[i+1]);
-    }
-    _LOG(log, scope_flags, "    scr %08lx\n", vfp_regs.fpscr);
-#endif
-}

debuggerd/arm/machine.cpp

+/* 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.
+*/
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/user.h>
+
+#include "../utility.h"
+#include "../machine.h"
+
+/* enable to dump memory pointed to by every register */
+#define DUMP_MEMORY_FOR_ALL_REGISTERS 1
+
+#ifdef WITH_VFP
+#ifdef WITH_VFP_D32
+#define NUM_VFP_REGS 32
+#else
+#define NUM_VFP_REGS 16
+#endif
+#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 */
+    uintptr_t p, end;
+
+    p = addr & ~3;
+    p -= 32;
+    if (p > addr) {
+        /* catch underflow */
+        p = 0;
+    }
+    /* Dump more memory content for the crashing thread. */
+    end = p + 256;
+    /* 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......
+     */
+    while (p < end) {
+        char* asc_out = ascii_buffer;
+
+        sprintf(code_buffer, "%08x ", p);
+
+        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);
+            sprintf(code_buffer + strlen(code_buffer), "%08lx ", data);
+
+            /* 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.
+                 */
+                char val = (data >> (j*8)) & 0xff;
+                if (val >= 0x20 && val < 0x7f) {
+                    *asc_out++ = val;
+                } else {
+                    *asc_out++ = '.';
+                }
+            }
+#endif
+            p += 4;
+        }
+        *asc_out = '\0';
+        _LOG(log, scope_flags, "    %s %s\n", code_buffer, ascii_buffer);
+    }
+}
+
+/*
+ * 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)) {
+        return;
+    }
+
+    if (IS_AT_FAULT(scope_flags) && DUMP_MEMORY_FOR_ALL_REGISTERS) {
+        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 */
+            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.
+             */
+            if (addr < 4096 || addr >= 0xc0000000) {
+                continue;
+            }
+
+            _LOG(log, scope_flags | SCOPE_SENSITIVE, "\nmemory near %.2s:\n", &REG_NAMES[reg * 2]);
+            dump_memory(log, tid, addr, scope_flags | SCOPE_SENSITIVE);
+        }
+    }
+
+    /* 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);
+
+    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);
+    }
+}
+
+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));
+        return;
+    }
+
+    _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);
+    _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);
+    _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);
+    _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);
+
+#ifdef WITH_VFP
+    struct user_vfp vfp_regs;
+    int i;
+
+    if(ptrace(PTRACE_GETVFPREGS, tid, 0, &vfp_regs)) {
+        _LOG(log, scope_flags, "cannot get registers: %s\n", strerror(errno));
+        return;
+    }
+
+    for (i = 0; i < NUM_VFP_REGS; i += 2) {
+        _LOG(log, scope_flags, "    d%-2d %016llx  d%-2d %016llx\n",
+                i, vfp_regs.fpregs[i], i+1, vfp_regs.fpregs[i+1]);
+    }
+    _LOG(log, scope_flags, "    scr %08lx\n", vfp_regs.fpscr);
+#endif
+}

debuggerd/backtrace.c

-/*
- * Copyright (C) 2012 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 <stddef.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <time.h>
-#include <errno.h>
-#include <limits.h>
-#include <dirent.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/ptrace.h>
-
-#include <backtrace/backtrace.h>
-
-#include "backtrace.h"
-#include "utility.h"
-
-static void dump_process_header(log_t* log, pid_t pid) {
-    char path[PATH_MAX];
-    char procnamebuf[1024];
-    char* procname = NULL;
-    FILE* fp;
-
-    snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
-    if ((fp = fopen(path, "r"))) {
-        procname = fgets(procnamebuf, sizeof(procnamebuf), fp);
-        fclose(fp);
-    }
-
-    time_t t = time(NULL);
-    struct tm tm;
-    localtime_r(&t, &tm);
-    char timestr[64];
-    strftime(timestr, sizeof(timestr), "%F %T", &tm);
-    _LOG(log, SCOPE_AT_FAULT, "\n\n----- pid %d at %s -----\n", pid, timestr);
-
-    if (procname) {
-        _LOG(log, SCOPE_AT_FAULT, "Cmd line: %s\n", procname);
-    }
-}
-
-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) {
-    char path[PATH_MAX];
-    char threadnamebuf[1024];
-    char* threadname = NULL;
-    FILE* fp;
-
-    snprintf(path, sizeof(path), "/proc/%d/comm", tid);
-    if ((fp = fopen(path, "r"))) {
-        threadname = fgets(threadnamebuf, sizeof(threadnamebuf), fp);
-        fclose(fp);
-        if (threadname) {
-            size_t len = strlen(threadname);
-            if (len && threadname[len - 1] == '\n') {
-                threadname[len - 1] = '\0';
-            }
-        }
-    }
-
-    _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));
-        return;
-    }
-
-    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);
-    }
-
-    if (!attached && ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
-        LOG("ptrace detach from %d failed: %s\n", tid, strerror(errno));
-        *detach_failed = true;
-    }
-}
-
-void dump_backtrace(int fd, int amfd, pid_t pid, pid_t tid, bool* detach_failed,
-        int* total_sleep_time_usec) {
-    log_t log;
-    log.tfd = fd;
-    log.amfd = amfd;
-    log.quiet = true;
-
-    dump_process_header(&log, pid);
-    dump_thread(&log, tid, true, detach_failed, total_sleep_time_usec);
-
-    char task_path[64];
-    snprintf(task_path, sizeof(task_path), "/proc/%d/task", pid);
-    DIR* d = opendir(task_path);
-    if (d != NULL) {
-        struct dirent* de = NULL;
-        while ((de = readdir(d)) != NULL) {
-            if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
-                continue;
-            }
-
-            char* end;
-            pid_t new_tid = strtoul(de->d_name, &end, 10);
-            if (*end || new_tid == tid) {
-                continue;
-            }
-
-            dump_thread(&log, new_tid, false, detach_failed, total_sleep_time_usec);
-        }
-        closedir(d);
-    }
-
-    dump_process_footer(&log, pid);
-}
-
-void dump_backtrace_to_log(const backtrace_context_t* context, 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);
-    }
-}

debuggerd/backtrace.cpp

+/*
+ * Copyright (C) 2012 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 <stddef.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <time.h>
+#include <errno.h>
+#include <limits.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/ptrace.h>
+
+#include <backtrace/backtrace.h>
+
+#include "backtrace.h"
+#include "utility.h"
+
+static void dump_process_header(log_t* log, pid_t pid) {
+    char path[PATH_MAX];
+    char procnamebuf[1024];
+    char* procname = NULL;
+    FILE* fp;
+
+    snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
+    if ((fp = fopen(path, "r"))) {
+        procname = fgets(procnamebuf, sizeof(procnamebuf), fp);
+        fclose(fp);
+    }
+
+    time_t t = time(NULL);
+    struct tm tm;
+    localtime_r(&t, &tm);
+    char timestr[64];
+    strftime(timestr, sizeof(timestr), "%F %T", &tm);
+    _LOG(log, SCOPE_AT_FAULT, "\n\n----- pid %d at %s -----\n", pid, timestr);
+
+    if (procname) {
+        _LOG(log, SCOPE_AT_FAULT, "Cmd line: %s\n", procname);
+    }
+}
+
+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) {
+    char path[PATH_MAX];
+    char threadnamebuf[1024];
+    char* threadname = NULL;
+    FILE* fp;
+
+    snprintf(path, sizeof(path), "/proc/%d/comm", tid);
+    if ((fp = fopen(path, "r"))) {
+        threadname = fgets(threadnamebuf, sizeof(threadnamebuf), fp);
+        fclose(fp);
+        if (threadname) {
+            size_t len = strlen(threadname);
+            if (len && threadname[len - 1] == '\n') {
+                threadname[len - 1] = '\0';
+            }
+        }
+    }
+
+    _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));
+        return;
+    }
+
+    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);
+    }
+
+    if (!attached && ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
+        LOG("ptrace detach from %d failed: %s\n", tid, strerror(errno));
+        *detach_failed = true;
+    }
+}
+
+void dump_backtrace(int fd, int amfd, pid_t pid, pid_t tid, bool* detach_failed,
+        int* total_sleep_time_usec) {
+    log_t log;
+    log.tfd = fd;
+    log.amfd = amfd;
+    log.quiet = true;
+
+    dump_process_header(&log, pid);
+    dump_thread(&log, tid, true, detach_failed, total_sleep_time_usec);
+
+    char task_path[64];
+    snprintf(task_path, sizeof(task_path), "/proc/%d/task", pid);
+    DIR* d = opendir(task_path);
+    if (d != NULL) {
+        struct dirent* de = NULL;
+        while ((de = readdir(d)) != NULL) {
+            if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
+                continue;
+            }
+
+            char* end;
+            pid_t new_tid = strtoul(de->d_name, &end, 10);
+            if (*end || new_tid == tid) {
+                continue;
+            }
+
+            dump_thread(&log, new_tid, false, detach_failed, total_sleep_time_usec);
+        }
+        closedir(d);
+    }
+
+    dump_process_footer(&log, pid);
+}
+
+void dump_backtrace_to_log(const backtrace_context_t* context, 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);
+    }
+}

debuggerd/debuggerd.c

-/* 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.
-*/
-
-#include <stdio.h>
-#include <errno.h>
-#include <signal.h>
-#include <pthread.h>
-#include <stdarg.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <dirent.h>
-#include <time.h>
-
-#include <sys/ptrace.h>
-#include <sys/wait.h>
-#include <elf.h>
-#include <sys/stat.h>
-#include <sys/poll.h>
-
-#include <log/logd.h>
-#include <log/logger.h>
-
-#include <cutils/sockets.h>
-#include <cutils/properties.h>
-#include <cutils/debugger.h>
-
-#include <corkscrew/backtrace.h>
-
-#include <linux/input.h>
-
-#include <private/android_filesystem_config.h>
-
-#include "backtrace.h"
-#include "getevent.h"
-#include "tombstone.h"
-#include "utility.h"
-
-typedef struct {
-    debugger_action_t action;
-    pid_t pid, tid;
-    uid_t uid, gid;
-    uintptr_t abort_msg_address;
-} debugger_request_t;
-
-static int
-write_string(const char* file, const char* string)
-{
-    int len;
-    int fd;
-    ssize_t amt;
-    fd = open(file, O_RDWR);
-    len = strlen(string);
-    if (fd < 0)
-        return -errno;
-    amt = write(fd, string, len);
-    close(fd);
-    return amt >= 0 ? 0 : -errno;
-}
-
-static
-void init_debug_led(void)
-{
-    // trout leds
-    write_string("/sys/class/leds/red/brightness", "0");
-    write_string("/sys/class/leds/green/brightness", "0");
-    write_string("/sys/class/leds/blue/brightness", "0");
-    write_string("/sys/class/leds/red/device/blink", "0");
-    // sardine leds
-    write_string("/sys/class/leds/left/cadence", "0,0");
-}
-
-static
-void enable_debug_led(void)
-{
-    // 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)
-{
-    // trout leds
-    write_string("/sys/class/leds/red/brightness", "0");
-    // sardine leds
-    write_string("/sys/class/leds/left/cadence", "0,0");
-}
-
-static void wait_for_user_action(pid_t pid) {
-    /* 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"
-            "* and start gdbclient:\n"
-            "*\n"
-            "*     gdbclient app_process :5039 %d\n"
-            "*\n"
-            "* Wait for gdb to start, then press HOME or VOLUME DOWN key\n"
-            "* to let the process continue crashing.\n"
-            "********************************************************\n",
-            pid, pid);
-
-    /* wait for HOME or VOLUME DOWN key */
-    if (init_getevent() == 0) {
-        int ms = 1200 / 10;
-        int dit = 1;
-        int dah = 3*dit;
-        int _       = -dit;
-        int ___     = 3*_;
-        int _______ = 7*_;
-        const signed char codes[] = {
-           dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
-        };
-        size_t s = 0;
-        struct input_event e;
-        bool done = false;
-        init_debug_led();
-        enable_debug_led();
-        do {
-            int timeout = abs((int)(codes[s])) * ms;
-            int res = get_event(&e, timeout);
-            if (res == 0) {
-                if (e.type == EV_KEY
-                        && (e.code == KEY_HOME || e.code == KEY_VOLUMEDOWN)
-                        && e.value == 0) {
-                    done = true;
-                }
-            } else if (res == 1) {
-                if (++s >= sizeof(codes)/sizeof(*codes))
-                    s = 0;
-                if (codes[s] > 0) {
-                    enable_debug_led();
-                } else {
-                    disable_debug_led();
-                }
-            }
-        } while (!done);
-        uninit_getevent();
-    }
-
-    /* don't forget to turn debug led off */
-    disable_debug_led();
-    LOG("debuggerd resuming process %d", pid);
-}
-
-static int get_process_info(pid_t tid, pid_t* out_pid, uid_t* out_uid, uid_t* out_gid) {
-    char path[64];
-    snprintf(path, sizeof(path), "/proc/%d/status", tid);
-
-    FILE* fp = fopen(path, "r");
-    if (!fp) {
-        return -1;
-    }
-
-    int fields = 0;
-    char line[1024];
-    while (fgets(line, sizeof(line), fp)) {
-        size_t len = strlen(line);
-        if (len > 6 && !memcmp(line, "Tgid:\t", 6)) {
-            *out_pid = atoi(line + 6);
-            fields |= 1;
-        } else if (len > 5 && !memcmp(line, "Uid:\t", 5)) {
-            *out_uid = atoi(line + 5);
-            fields |= 2;
-        } else if (len > 5 && !memcmp(line, "Gid:\t", 5)) {
-            *out_gid = atoi(line + 5);
-            fields |= 4;
-        }
-    }
-    fclose(fp);
-    return fields == 7 ? 0 : -1;
-}
-
-static int read_request(int fd, debugger_request_t* out_request) {
-    struct ucred cr;
-    int len = sizeof(cr);
-    int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
-    if (status != 0) {
-        LOG("cannot get credentials\n");
-        return -1;
-    }
-
-    XLOG("reading tid\n");
-    fcntl(fd, F_SETFL, O_NONBLOCK);
-
-    struct pollfd pollfds[1];
-    pollfds[0].fd = fd;
-    pollfds[0].events = POLLIN;
-    pollfds[0].revents = 0;
-    status = TEMP_FAILURE_RETRY(poll(pollfds, 1, 3000));
-    if (status != 1) {
-        LOG("timed out reading tid (from pid=%d uid=%d)\n", cr.pid, cr.uid);
-        return -1;
-    }
-
-    debugger_msg_t msg;
-    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);
-        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);
-        return -1;
-    }
-
-    out_request->action = msg.action;
-    out_request->tid = msg.tid;
-    out_request->pid = cr.pid;
-    out_request->uid = cr.uid;
-    out_request->gid = cr.gid;
-    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. */
-        char buf[64];
-        struct stat s;
-        snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
-        if(stat(buf, &s)) {
-            LOG("tid %d does not exist in pid %d. ignoring debug request\n",
-                    out_request->tid, out_request->pid);
-            return -1;
-        }
-    } 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. */
-        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);
-            return -1;
-        }
-    } else {
-        /* No one else is allowed to dump arbitrary processes. */
-        return -1;
-    }
-    return 0;
-}
-
-static bool should_attach_gdb(debugger_request_t* request) {
-    if (request->action == DEBUGGER_ACTION_CRASH) {
-        char value[PROPERTY_VALUE_MAX];
-        property_get("debug.db.uid", value, "-1");
-        int debug_uid = atoi(value);
-        return debug_uid >= 0 && request->uid <= (uid_t)debug_uid;
-    }
-    return false;
-}
-
-static void handle_request(int fd) {
-    XLOG("handle_request(%d)\n", fd);
-
-    debugger_request_t request;
-    memset(&request, 0, sizeof(request));
-    int status = read_request(fd, &request);
-    if (!status) {
-        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().
-         */
-        if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
-            LOG("ptrace attach failed: %s\n", strerror(errno));
-        } else {
-            bool detach_failed = false;
-            bool attach_gdb = should_attach_gdb(&request);
-            if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
-                LOG("failed responding to client: %s\n", strerror(errno));
-            } else {
-                char* tombstone_path = NULL;
-
-                if (request.action == DEBUGGER_ACTION_CRASH) {
-                    close(fd);
-                    fd = -1;
-                }
-
-                int total_sleep_time_usec = 0;
-                for (;;) {
-                    int signal = wait_for_signal(request.tid, &total_sleep_time_usec);
-                    if (signal < 0) {
-                        break;
-                    }
-
-                    switch (signal) {
-                    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);
-                        } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
-                            XLOG("stopped -- dumping to fd\n");
-                            dump_backtrace(fd, -1,
-                                    request.pid, request.tid, &detach_failed,
-                                    &total_sleep_time_usec);
-                        } else {
-                            XLOG("stopped -- continuing\n");
-                            status = ptrace(PTRACE_CONT, request.tid, 0, 0);
-                            if (status) {
-                                LOG("ptrace continue failed: %s\n", strerror(errno));
-                            }
-                            continue; /* loop again */
-                        }
-                        break;
-
-                    case SIGILL:
-                    case SIGABRT:
-                    case SIGBUS:
-                    case SIGFPE:
-                    case SIGSEGV:
-                    case SIGPIPE:
-#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".
-                         */
-                        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);
-                        break;
-                    }
-
-                    default:
-                        XLOG("stopped -- unexpected signal\n");
-                        LOG("process stopped due to unexpected signal %d\n", signal);
-                        break;
-                    }
-                    break;
-                }
-
-                if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
-                    if (tombstone_path) {
-                        write(fd, tombstone_path, strlen(tombstone_path));
-                    }
-                    close(fd);
-                    fd = -1;
-                }
-                free(tombstone_path);
-            }
-
-            XLOG("detaching\n");
-            if (attach_gdb) {
-                /* stop the process so we can debug */
-                kill(request.pid, SIGSTOP);
-
-                /* 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)
-                 */
-                wait_for_user_action(request.pid);
-            } else {
-                /* 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). */
-            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 (detach_failed) {
-                LOG("debuggerd committing suicide to free the zombie!\n");
-                kill(getpid(), SIGKILL);
-            }
-        }
-
-    }
-    if (fd >= 0) {
-        close(fd);
-    }
-}
-
-static int do_server() {
-    int s;
-    struct sigaction act;
-    int logsocket = -1;
-
-    /*
-     * 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);
-    signal(SIGFPE, SIG_DFL);
-    signal(SIGSEGV, SIG_DFL);
-#ifdef SIGSTKFLT
-    signal(SIGSTKFLT, SIG_DFL);
-#endif
-
-    // Ignore failed writes to closed sockets
-    signal(SIGPIPE, SIG_IGN);
-
-    logsocket = socket_local_client("logd",
-            ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
-    if(logsocket < 0) {
-        logsocket = -1;
-    } else {
-        fcntl(logsocket, F_SETFD, FD_CLOEXEC);
-    }
-
-    act.sa_handler = SIG_DFL;
-    sigemptyset(&act.sa_mask);
-    sigaddset(&act.sa_mask,SIGCHLD);
-    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;
-    fcntl(s, F_SETFD, FD_CLOEXEC);
-
-    LOG("debuggerd: " __DATE__ " " __TIME__ "\n");
-
-    for(;;) {
-        struct sockaddr addr;
-        socklen_t alen;
-        int fd;
-
-        alen = sizeof(addr);
-        XLOG("waiting for connection\n");
-        fd = accept(s, &addr, &alen);
-        if(fd < 0) {
-            XLOG("accept failed: %s\n", strerror(errno));
-            continue;
-        }
-
-        fcntl(fd, F_SETFD, FD_CLOEXEC);
-
-        handle_request(fd);
-    }
-    return 0;
-}
-
-static int do_explicit_dump(pid_t tid, bool dump_backtrace) {
-    fprintf(stdout, "Sending request to dump task %d.\n", tid);
-
-    if (dump_backtrace) {
-        fflush(stdout);
-        if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
-            fputs("Error dumping backtrace.\n", stderr);
-            return 1;
-        }
-    } else {
-        char tombstone_path[PATH_MAX];
-        if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
-            fputs("Error dumping tombstone.\n", stderr);
-            return 1;
-        }
-        fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
-    }
-    return 0;
-}
-
-static void usage() {
-    fputs("Usage: -b [<tid>]\n"
-            "  -b dump backtrace to console, otherwise dump full tombstone file\n"
-            "\n"
-            "If tid specified, sends a request to debuggerd to dump that task.\n"
-            "Otherwise, starts the debuggerd server.\n", stderr);
-}
-
-int main(int argc, char** argv) {
-    if (argc == 1) {
-        return do_server();
-    }
-
-    bool dump_backtrace = false;
-    bool have_tid = false;
-    pid_t tid = 0;
-    for (int i = 1; i < argc; i++) {
-        if (!strcmp(argv[i], "-b")) {
-            dump_backtrace = true;
-        } else if (!have_tid) {
-            tid = atoi(argv[i]);
-            have_tid = true;
-        } else {
-            usage();
-            return 1;
-        }
-    }
-    if (!have_tid) {
-        usage();
-        return 1;
-    }
-    return do_explicit_dump(tid, dump_backtrace);
-}

debuggerd/debuggerd.cpp

+/* 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.
+*/
+
+#include <stdio.h>
+#include <errno.h>
+#include <signal.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <time.h>
+
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <elf.h>
+#include <sys/stat.h>
+#include <sys/poll.h>
+
+#include <log/logd.h>
+#include <log/logger.h>
+
+#include <cutils/sockets.h>
+#include <cutils/properties.h>
+#include <cutils/debugger.h>
+
+#include <corkscrew/backtrace.h>
+
+#include <linux/input.h>
+
+#include <private/android_filesystem_config.h>
+
+#include "backtrace.h"
+#include "getevent.h"
+#include "tombstone.h"
+#include "utility.h"
+
+typedef struct {
+    debugger_action_t action;
+    pid_t pid, tid;
+    uid_t uid, gid;
+    uintptr_t abort_msg_address;
+} debugger_request_t;
+
+static int
+write_string(const char* file, const char* string)
+{
+    int len;
+    int fd;
+    ssize_t amt;
+    fd = open(file, O_RDWR);
+    len = strlen(string);
+    if (fd < 0)
+        return -errno;
+    amt = write(fd, string, len);
+    close(fd);
+    return amt >= 0 ? 0 : -errno;
+}
+
+static
+void init_debug_led(void)
+{
+    // trout leds
+    write_string("/sys/class/leds/red/brightness", "0");
+    write_string("/sys/class/leds/green/brightness", "0");
+    write_string("/sys/class/leds/blue/brightness", "0");
+    write_string("/sys/class/leds/red/device/blink", "0");
+    // sardine leds
+    write_string("/sys/class/leds/left/cadence", "0,0");
+}
+
+static
+void enable_debug_led(void)
+{
+    // 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)
+{
+    // trout leds
+    write_string("/sys/class/leds/red/brightness", "0");
+    // sardine leds
+    write_string("/sys/class/leds/left/cadence", "0,0");
+}
+
+static void wait_for_user_action(pid_t pid) {
+    /* 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"
+            "* and start gdbclient:\n"
+            "*\n"
+            "*     gdbclient app_process :5039 %d\n"
+            "*\n"
+            "* Wait for gdb to start, then press HOME or VOLUME DOWN key\n"
+            "* to let the process continue crashing.\n"
+            "********************************************************\n",
+            pid, pid);
+
+    /* wait for HOME or VOLUME DOWN key */
+    if (init_getevent() == 0) {
+        int ms = 1200 / 10;
+        int dit = 1;
+        int dah = 3*dit;
+        int _       = -dit;
+        int ___     = 3*_;
+        int _______ = 7*_;
+        const int codes[] = {
+           dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
+        };
+        size_t s = 0;
+        struct input_event e;
+        bool done = false;
+        init_debug_led();
+        enable_debug_led();
+        do {
+            int timeout = abs(codes[s]) * ms;
+            int res = get_event(&e, timeout);
+            if (res == 0) {
+                if (e.type == EV_KEY
+                        && (e.code == KEY_HOME || e.code == KEY_VOLUMEDOWN)
+                        && e.value == 0) {
+                    done = true;
+                }
+            } else if (res == 1) {
+                if (++s >= sizeof(codes)/sizeof(*codes))
+                    s = 0;
+                if (codes[s] > 0) {
+                    enable_debug_led();
+                } else {
+                    disable_debug_led();
+                }
+            }
+        } while (!done);
+        uninit_getevent();
+    }
+
+    /* don't forget to turn debug led off */
+    disable_debug_led();
+    LOG("debuggerd resuming process %d", pid);
+}
+
+static int get_process_info(pid_t tid, pid_t* out_pid, uid_t* out_uid, uid_t* out_gid) {
+    char path[64];
+    snprintf(path, sizeof(path), "/proc/%d/status", tid);
+
+    FILE* fp = fopen(path, "r");
+    if (!fp) {
+        return -1;
+    }
+
+    int fields = 0;
+    char line[1024];
+    while (fgets(line, sizeof(line), fp)) {
+        size_t len = strlen(line);
+        if (len > 6 && !memcmp(line, "Tgid:\t", 6)) {
+            *out_pid = atoi(line + 6);
+            fields |= 1;
+        } else if (len > 5 && !memcmp(line, "Uid:\t", 5)) {
+            *out_uid = atoi(line + 5);
+            fields |= 2;
+        } else if (len > 5 && !memcmp(line, "Gid:\t", 5)) {
+            *out_gid = atoi(line + 5);
+            fields |= 4;
+        }
+    }
+    fclose(fp);
+    return fields == 7 ? 0 : -1;
+}
+
+static int read_request(int fd, debugger_request_t* out_request) {
+    struct ucred cr;
+    int len = sizeof(cr);
+    int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+    if (status != 0) {
+        LOG("cannot get credentials\n");
+        return -1;
+    }
+
+    XLOG("reading tid\n");
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+
+    struct pollfd pollfds[1];
+    pollfds[0].fd = fd;
+    pollfds[0].events = POLLIN;
+    pollfds[0].revents = 0;
+    status = TEMP_FAILURE_RETRY(poll(pollfds, 1, 3000));
+    if (status != 1) {
+        LOG("timed out reading tid (from pid=%d uid=%d)\n", cr.pid, cr.uid);
+        return -1;
+    }
+
+    debugger_msg_t msg;
+    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);
+        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);
+        return -1;
+    }
+
+    out_request->action = msg.action;
+    out_request->tid = msg.tid;
+    out_request->pid = cr.pid;
+    out_request->uid = cr.uid;
+    out_request->gid = cr.gid;
+    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. */
+        char buf[64];
+        struct stat s;
+        snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
+        if(stat(buf, &s)) {
+            LOG("tid %d does not exist in pid %d. ignoring debug request\n",
+                    out_request->tid, out_request->pid);
+            return -1;
+        }
+    } 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. */
+        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);
+            return -1;
+        }
+    } else {
+        /* No one else is allowed to dump arbitrary processes. */
+        return -1;
+    }
+    return 0;
+}
+
+static bool should_attach_gdb(debugger_request_t* request) {
+    if (request->action == DEBUGGER_ACTION_CRASH) {
+        char value[PROPERTY_VALUE_MAX];
+        property_get("debug.db.uid", value, "-1");
+        int debug_uid = atoi(value);
+        return debug_uid >= 0 && request->uid <= (uid_t)debug_uid;
+    }
+    return false;
+}
+
+static void handle_request(int fd) {
+    XLOG("handle_request(%d)\n", fd);
+
+    debugger_request_t request;
+    memset(&request, 0, sizeof(request));
+    int status = read_request(fd, &request);
+    if (!status) {
+        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().
+         */
+        if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
+            LOG("ptrace attach failed: %s\n", strerror(errno));
+        } else {
+            bool detach_failed = false;
+            bool attach_gdb = should_attach_gdb(&request);
+            if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
+                LOG("failed responding to client: %s\n", strerror(errno));
+            } else {
+                char* tombstone_path = NULL;
+
+                if (request.action == DEBUGGER_ACTION_CRASH) {
+                    close(fd);
+                    fd = -1;
+                }
+
+                int total_sleep_time_usec = 0;
+                for (;;) {
+                    int signal = wait_for_signal(request.tid, &total_sleep_time_usec);
+                    if (signal < 0) {
+                        break;
+                    }
+
+                    switch (signal) {
+                    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);
+                        } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
+                            XLOG("stopped -- dumping to fd\n");
+                            dump_backtrace(fd, -1,
+                                    request.pid, request.tid, &detach_failed,
+                                    &total_sleep_time_usec);
+                        } else {
+                            XLOG("stopped -- continuing\n");
+                            status = ptrace(PTRACE_CONT, request.tid, 0, 0);
+                            if (status) {
+                                LOG("ptrace continue failed: %s\n", strerror(errno));
+                            }
+                            continue; /* loop again */
+                        }
+                        break;
+
+                    case SIGILL:
+                    case SIGABRT:
+                    case SIGBUS:
+                    case SIGFPE:
+                    case SIGSEGV:
+                    case SIGPIPE:
+#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".
+                         */
+                        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);
+                        break;
+                    }
+
+                    default:
+                        XLOG("stopped -- unexpected signal\n");
+                        LOG("process stopped due to unexpected signal %d\n", signal);
+                        break;
+                    }
+                    break;
+                }
+
+                if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
+                    if (tombstone_path) {
+                        write(fd, tombstone_path, strlen(tombstone_path));
+                    }
+                    close(fd);
+                    fd = -1;
+                }
+                free(tombstone_path);
+            }
+
+            XLOG("detaching\n");
+            if (attach_gdb) {
+                /* stop the process so we can debug */
+                kill(request.pid, SIGSTOP);
+
+                /* 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)
+                 */
+                wait_for_user_action(request.pid);
+            } else {
+                /* 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). */
+            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 (detach_failed) {
+                LOG("debuggerd committing suicide to free the zombie!\n");
+                kill(getpid(), SIGKILL);
+            }
+        }
+
+    }
+    if (fd >= 0) {
+        close(fd);
+    }
+}
+
+static int do_server() {
+    int s;
+    struct sigaction act;
+    int logsocket = -1;
+
+    /*
+     * 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);
+    signal(SIGFPE, SIG_DFL);
+    signal(SIGSEGV, SIG_DFL);
+#ifdef SIGSTKFLT
+    signal(SIGSTKFLT, SIG_DFL);
+#endif
+
+    // Ignore failed writes to closed sockets
+    signal(SIGPIPE, SIG_IGN);
+
+    logsocket = socket_local_client("logd",
+            ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
+    if(logsocket < 0) {
+        logsocket = -1;
+    } else {
+        fcntl(logsocket, F_SETFD, FD_CLOEXEC);
+    }
+
+    act.sa_handler = SIG_DFL;
+    sigemptyset(&act.sa_mask);
+    sigaddset(&act.sa_mask,SIGCHLD);
+    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;
+    fcntl(s, F_SETFD, FD_CLOEXEC);
+
+    LOG("debuggerd: " __DATE__ " " __TIME__ "\n");
+
+    for(;;) {
+        struct sockaddr addr;
+        socklen_t alen;
+        int fd;
+
+        alen = sizeof(addr);
+        XLOG("waiting for connection\n");
+        fd = accept(s, &addr, &alen);
+        if(fd < 0) {
+            XLOG("accept failed: %s\n", strerror(errno));
+            continue;
+        }
+
+        fcntl(fd, F_SETFD, FD_CLOEXEC);
+
+        handle_request(fd);
+    }
+    return 0;
+}
+
+static int do_explicit_dump(pid_t tid, bool dump_backtrace) {
+    fprintf(stdout, "Sending request to dump task %d.\n", tid);
+
+    if (dump_backtrace) {
+        fflush(stdout);
+        if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
+            fputs("Error dumping backtrace.\n", stderr);
+            return 1;
+        }
+    } else {
+        char tombstone_path[PATH_MAX];
+        if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
+            fputs("Error dumping tombstone.\n", stderr);
+            return 1;
+        }
+        fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
+    }
+    return 0;
+}
+
+static void usage() {
+    fputs("Usage: -b [<tid>]\n"
+            "  -b dump backtrace to console, otherwise dump full tombstone file\n"
+            "\n"
+            "If tid specified, sends a request to debuggerd to dump that task.\n"
+            "Otherwise, starts the debuggerd server.\n", stderr);
+}
+
+int main(int argc, char** argv) {
+    if (argc == 1) {
+        return do_server();
+    }
+
+    bool dump_backtrace = false;
+    bool have_tid = false;
+    pid_t tid = 0;
+    for (int i = 1; i < argc; i++) {
+        if (!strcmp(argv[i], "-b")) {
+            dump_backtrace = true;
+        } else if (!have_tid) {
+            tid = atoi(argv[i]);
+            have_tid = true;
+        } else {
+            usage();
+            return 1;
+        }
+    }
+    if (!have_tid) {
+        usage();
+        return 1;
+    }
+    return do_explicit_dump(tid, dump_backtrace);
+}

debuggerd/getevent.c

-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdint.h>
-#include <dirent.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#include <sys/inotify.h>
-#include <sys/limits.h>
-#include <sys/poll.h>
-#include <linux/input.h>
-#include <errno.h>
-#include <cutils/log.h>
-
-static struct pollfd *ufds;
-static char **device_names;
-static int nfds;
-
-static int open_device(const char *device)
-{
-    int version;
-    int fd;
-    struct pollfd *new_ufds;
-    char **new_device_names;
-    char name[80];
-    char location[80];
-    char idstr[80];
-    struct input_id id;
-
-    fd = open(device, O_RDWR);
-    if(fd < 0) {
-        return -1;
-    }
-    
-    if(ioctl(fd, EVIOCGVERSION, &version)) {
-        return -1;
-    }
-    if(ioctl(fd, EVIOCGID, &id)) {
-        return -1;
-    }
-    name[sizeof(name) - 1] = '\0';
-    location[sizeof(location) - 1] = '\0';
-    idstr[sizeof(idstr) - 1] = '\0';
-    if(ioctl(fd, EVIOCGNAME(sizeof(name) - 1), &name) < 1) {
-        //fprintf(stderr, "could not get device name for %s, %s\n", device, strerror(errno));
-        name[0] = '\0';
-    }
-    if(ioctl(fd, EVIOCGPHYS(sizeof(location) - 1), &location) < 1) {
-        //fprintf(stderr, "could not get location for %s, %s\n", device, strerror(errno));
-        location[0] = '\0';
-    }
-    if(ioctl(fd, EVIOCGUNIQ(sizeof(idstr) - 1), &idstr) < 1) {
-        //fprintf(stderr, "could not get idstring for %s, %s\n", device, strerror(errno));
-        idstr[0] = '\0';
-    }
-
-    new_ufds = realloc(ufds, sizeof(ufds[0]) * (nfds + 1));
-    if(new_ufds == NULL) {
-        fprintf(stderr, "out of memory\n");
-        return -1;
-    }
-    ufds = new_ufds;
-    new_device_names = realloc(device_names, sizeof(device_names[0]) * (nfds + 1));
-    if(new_device_names == NULL) {
-        fprintf(stderr, "out of memory\n");
-        return -1;
-    }
-    device_names = new_device_names;
-    ufds[nfds].fd = fd;
-    ufds[nfds].events = POLLIN;
-    device_names[nfds] = strdup(device);
-    nfds++;
-
-    return 0;
-}
-
-int close_device(const char *device)
-{
-    int i;
-    for(i = 1; i < nfds; i++) {
-        if(strcmp(device_names[i], device) == 0) {
-            int count = nfds - i - 1;
-            free(device_names[i]);
-            memmove(device_names + i, device_names + i + 1, sizeof(device_names[0]) * count);
-            memmove(ufds + i, ufds + i + 1, sizeof(ufds[0]) * count);
-            nfds--;
-            return 0;
-        }
-    }
-    return -1;
-}
-
-static int read_notify(const char *dirname, int nfd)
-{
-    int res;
-    char devname[PATH_MAX];
-    char *filename;
-    char event_buf[512];
-    int event_size;
-    int event_pos = 0;
-    struct inotify_event *event;
-
-    res = read(nfd, event_buf, sizeof(event_buf));
-    if(res < (int)sizeof(*event)) {
-        if(errno == EINTR)
-            return 0;
-        fprintf(stderr, "could not get event, %s\n", strerror(errno));
-        return 1;
-    }
-    //printf("got %d bytes of event information\n", res);
-
-    strcpy(devname, dirname);
-    filename = devname + strlen(devname);
-    *filename++ = '/';
-
-    while(res >= (int)sizeof(*event)) {
-        event = (struct inotify_event *)(event_buf + event_pos);
-        //printf("%d: %08x \"%s\"\n", event->wd, event->mask, event->len ? event->name : "");
-        if(event->len) {
-            strcpy(filename, event->name);
-            if(event->mask & IN_CREATE) {
-                open_device(devname);
-            }
-            else {
-                close_device(devname);
-            }
-        }
-        event_size = sizeof(*event) + event->len;
-        res -= event_size;
-        event_pos += event_size;
-    }
-    return 0;
-}
-
-static int scan_dir(const char *dirname)
-{
-    char devname[PATH_MAX];
-    char *filename;
-    DIR *dir;
-    struct dirent *de;
-    dir = opendir(dirname);
-    if(dir == NULL)
-        return -1;
-    strcpy(devname, dirname);
-    filename = devname + strlen(devname);
-    *filename++ = '/';
-    while((de = readdir(dir))) {
-        if(de->d_name[0] == '.' &&
-           (de->d_name[1] == '\0' ||
-            (de->d_name[1] == '.' && de->d_name[2] == '\0')))
-            continue;
-        strcpy(filename, de->d_name);
-        open_device(devname);
-    }
-    closedir(dir);
-    return 0;
-}
-
-int init_getevent()
-{
-    int res;
-    const char *device_path = "/dev/input";
-
-    nfds = 1;
-    ufds = calloc(1, sizeof(ufds[0]));
-    ufds[0].fd = inotify_init();
-    ufds[0].events = POLLIN;
-
-	res = inotify_add_watch(ufds[0].fd, device_path, IN_DELETE | IN_CREATE);
-    if(res < 0) {
-        return 1;
-    }
-    res = scan_dir(device_path);
-    if(res < 0) {
-        return 1;
-    }
-    return 0;
-}
-
-void uninit_getevent()
-{
-    int i;
-    for(i = 0; i < nfds; i++) {
-        close(ufds[i].fd);
-    }
-    free(ufds);
-    ufds = 0;
-    nfds = 0;
-}
-
-int get_event(struct input_event* event, int timeout)
-{
-    int res;
-    int i;
-    int pollres;
-    const char *device_path = "/dev/input";
-    while(1) {
-        pollres = poll(ufds, nfds, timeout);
-        if (pollres == 0) {
-            return 1;
-        }
-        if(ufds[0].revents & POLLIN) {
-            read_notify(device_path, ufds[0].fd);
-        }
-        for(i = 1; i < nfds; i++) {
-            if(ufds[i].revents) {
-                if(ufds[i].revents & POLLIN) {
-                    res = read(ufds[i].fd, event, sizeof(*event));
-                    if(res < (int)sizeof(event)) {
-                        fprintf(stderr, "could not get event\n");
-                        return -1;
-                    }
-                    return 0;
-                }
-            }
-        }
-    }
-    return 0;
-}

debuggerd/getevent.cpp

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/inotify.h>
+#include <sys/limits.h>
+#include <sys/poll.h>
+#include <linux/input.h>
+#include <errno.h>
+#include <cutils/log.h>
+
+static struct pollfd *ufds;
+static char **device_names;
+static int nfds;
+
+static int open_device(const char *device)
+{
+    int version;
+    int fd;
+    struct pollfd *new_ufds;
+    char **new_device_names;
+    char name[80];
+    char location[80];
+    char idstr[80];
+    struct input_id id;
+
+    fd = open(device, O_RDWR);
+    if(fd < 0) {
+        return -1;
+    }
+    
+    if(ioctl(fd, EVIOCGVERSION, &version)) {
+        return -1;
+    }
+    if(ioctl(fd, EVIOCGID, &id)) {
+        return -1;
+    }
+    name[sizeof(name) - 1] = '\0';
+    location[sizeof(location) - 1] = '\0';
+    idstr[sizeof(idstr) - 1] = '\0';
+    if(ioctl(fd, EVIOCGNAME(sizeof(name) - 1), &name) < 1) {
+        //fprintf(stderr, "could not get device name for %s, %s\n", device, strerror(errno));
+        name[0] = '\0';
+    }
+    if(ioctl(fd, EVIOCGPHYS(sizeof(location) - 1), &location) < 1) {
+        //fprintf(stderr, "could not get location for %s, %s\n", device, strerror(errno));
+        location[0] = '\0';
+    }
+    if(ioctl(fd, EVIOCGUNIQ(sizeof(idstr) - 1), &idstr) < 1) {
+        //fprintf(stderr, "could not get idstring for %s, %s\n", device, strerror(errno));
+        idstr[0] = '\0';
+    }
+
+    new_ufds = reinterpret_cast<pollfd*>(realloc(ufds, sizeof(ufds[0]) * (nfds + 1)));
+    if(new_ufds == NULL) {
+        fprintf(stderr, "out of memory\n");
+        return -1;
+    }
+    ufds = new_ufds;
+    new_device_names = reinterpret_cast<char**>(realloc(device_names, sizeof(device_names[0]) * (nfds + 1)));
+    if(new_device_names == NULL) {
+        fprintf(stderr, "out of memory\n");
+        return -1;
+    }
+    device_names = new_device_names;
+    ufds[nfds].fd = fd;
+    ufds[nfds].events = POLLIN;
+    device_names[nfds] = strdup(device);
+    nfds++;
+
+    return 0;
+}
+
+int close_device(const char *device)
+{
+    int i;
+    for(i = 1; i < nfds; i++) {
+        if(strcmp(device_names[i], device) == 0) {
+            int count = nfds - i - 1;
+            free(device_names[i]);
+            memmove(device_names + i, device_names + i + 1, sizeof(device_names[0]) * count);
+            memmove(ufds + i, ufds + i + 1, sizeof(ufds[0]) * count);
+            nfds--;
+            return 0;
+        }
+    }
+    return -1;
+}
+
+static int read_notify(const char *dirname, int nfd)
+{
+    int res;
+    char devname[PATH_MAX];
+    char *filename;
+    char event_buf[512];
+    int event_size;
+    int event_pos = 0;
+    struct inotify_event *event;
+
+    res = read(nfd, event_buf, sizeof(event_buf));
+    if(res < (int)sizeof(*event)) {
+        if(errno == EINTR)
+            return 0;
+        fprintf(stderr, "could not get event, %s\n", strerror(errno));
+        return 1;
+    }
+    //printf("got %d bytes of event information\n", res);
+
+    strcpy(devname, dirname);
+    filename = devname + strlen(devname);
+    *filename++ = '/';
+
+    while(res >= (int)sizeof(*event)) {
+        event = (struct inotify_event *)(event_buf + event_pos);