debuggerd_handler: add and use fatal_errno.

Bug: none
Test: mma
Change-Id: I24d913abdbe74f9463feda78f7817ca8b92af9cc

1 files changed, 22 insertions, 11 deletions

diff --git a/debuggerd/handler/debuggerd_handler.cpp b/debuggerd/handler/debuggerd_handler.cpp
index cd491d627..9469bbdeb 100644
--- a/debuggerd/handler/debuggerd_handler.cpp
+++ b/debuggerd/handler/debuggerd_handler.cpp
@@ -67,11 +67,22 @@ static debuggerd_callbacks_t g_callbacks;
 static pthread_mutex_t crash_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 // Don't use __libc_fatal because it exits via abort, which might put us back into a signal handler.
-#define fatal(...)                                             \
-  do {                                                         \
-    __libc_format_log(ANDROID_LOG_FATAL, "libc", __VA_ARGS__); \
-    _exit(1);                                                  \
-  } while (0)
+static void __noreturn __printflike(1, 2) fatal(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  __libc_format_log_va_list(ANDROID_LOG_FATAL, "libc", fmt, args);
+  _exit(1);
+}
+
+static void __noreturn __printflike(1, 2) fatal_errno(const char* fmt, ...) {
+  int err = errno;
+  va_list args;
+  va_start(args, fmt);
+
+  char buf[4096];
+  vsnprintf(buf, sizeof(buf), fmt, args);
+  fatal("%s: %s", buf, strerror(err));
+}
 
 /*
  * Writes a summary of the signal to the log file.  We do this so that, if
@@ -192,7 +203,7 @@ static int debuggerd_dispatch_pseudothread(void* arg) {
 
   int pipefds[2];
   if (pipe(pipefds) != 0) {
-    fatal("failed to create pipe");
+    fatal_errno("failed to create pipe");
   }
 
   // Don't use fork(2) to avoid calling pthread_atfork handlers.
@@ -209,7 +220,7 @@ static int debuggerd_dispatch_pseudothread(void* arg) {
     snprintf(buf, sizeof(buf), "%d", thread_info->crashing_tid);
     execl(CRASH_DUMP_PATH, CRASH_DUMP_NAME, buf, nullptr);
 
-    fatal("exec failed: %s", strerror(errno));
+    fatal_errno("exec failed");
   } else {
     close(pipefds[1]);
     char buf[4];
@@ -264,7 +275,7 @@ static void resend_signal(siginfo_t* info, bool crash_dump_started) {
   if (crash_dump_started || info->si_signo != DEBUGGER_SIGNAL) {
     int rc = syscall(SYS_rt_tgsigqueueinfo, getpid(), gettid(), info->si_signo, info);
     if (rc != 0) {
-      fatal("failed to resend signal during crash: %s", strerror(errno));
+      fatal_errno("failed to resend signal during crash");
     }
   }
 
@@ -336,7 +347,7 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void*)
           CLONE_THREAD | CLONE_SIGHAND | CLONE_VM | CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID,
           &thread_info, nullptr, nullptr, &thread_info.pseudothread_tid);
   if (child_pid == -1) {
-    fatal("failed to spawn debuggerd dispatch thread: %s", strerror(errno));
+    fatal_errno("failed to spawn debuggerd dispatch thread");
   }
 
   // Wait for the child to start...
@@ -366,12 +377,12 @@ void debuggerd_init(debuggerd_callbacks_t* callbacks) {
   void* thread_stack_allocation =
     mmap(nullptr, PAGE_SIZE * 3, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
   if (thread_stack_allocation == MAP_FAILED) {
-    fatal("failed to allocate debuggerd thread stack");
+    fatal_errno("failed to allocate debuggerd thread stack");
   }
 
   char* stack = static_cast<char*>(thread_stack_allocation) + PAGE_SIZE;
   if (mprotect(stack, PAGE_SIZE, PROT_READ | PROT_WRITE) != 0) {
-    fatal("failed to mprotect debuggerd thread stack");
+    fatal_errno("failed to mprotect debuggerd thread stack");
   }
 
   // Stack grows negatively, set it to the last byte in the page...