Enhance native stack dumps.

Provides a new mechanism for dumpstate (while running as root)
to request that debuggerd dump the stacks of native processes that
we care about in bug reports.  In this mode, the backtrace
is formatted to look similar to a Dalvik backtrace.

Moved the tombstone generating code into a separate file to
make it easier to maintain.

Fixed a bug where sometimes the stack traces would be incomplete
because we were not waiting for each thread to stop after issuing
PTRACE_ATTACH, only the main thread.  So sometimes we were missing
traces for some threads.

Refactored the logging code to prevent accidentally writing data
to logcat when explicitly dumping a tombstone or backtrace from the
console.

Only root or system server can request to dump backtraces but
only root can dump tombstones.

Bug: 6615693
Change-Id: Ib3edcc16f9f3a687e414e3f2d250d9500566123b

1 files changed, 17 insertions, 32 deletions

diff --git a/debuggerd/x86/machine.c b/debuggerd/x86/machine.c
index 2729c7edc..01da5fef0 100644
--- a/debuggerd/x86/machine.c
+++ b/debuggerd/x86/machine.c
@@ -15,59 +15,44 @@
 ** limitations under the License.
 */
 
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
 #include <stdio.h>
 #include <errno.h>
-#include <signal.h>
-#include <pthread.h>
-#include <fcntl.h>
 #include <sys/types.h>
-#include <dirent.h>
-
 #include <sys/ptrace.h>
-#include <sys/wait.h>
-#include <sys/exec_elf.h>
-#include <sys/stat.h>
-
-#include <cutils/sockets.h>
-#include <cutils/properties.h>
 
-#include <corkscrew/backtrace.h>
 #include <corkscrew/ptrace.h>
 
-#include <linux/input.h>
+#include <linux/user.h>
 
-#include "../machine.h"
 #include "../utility.h"
+#include "../machine.h"
+
+void dump_memory_and_code(const ptrace_context_t* context __attribute((unused)),
+        log_t* log, pid_t tid, bool at_fault) {
+}
 
-static void dump_registers(const ptrace_context_t* context __attribute((unused)),
-        int tfd, pid_t tid, bool at_fault) {
+void dump_registers(const ptrace_context_t* context __attribute((unused)),
+        log_t* log, pid_t tid, bool at_fault) {
     struct pt_regs_x86 r;
     bool only_in_tombstone = !at_fault;
 
     if(ptrace(PTRACE_GETREGS, tid, 0, &r)) {
-        _LOG(tfd, only_in_tombstone, "cannot get registers: %s\n", strerror(errno));
+        _LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno));
         return;
     }
     //if there is no stack, no print just like arm
     if(!r.ebp)
         return;
-    _LOG(tfd, only_in_tombstone, "    eax %08x  ebx %08x  ecx %08x  edx %08x\n",
+    _LOG(log, only_in_tombstone, "    eax %08x  ebx %08x  ecx %08x  edx %08x\n",
          r.eax, r.ebx, r.ecx, r.edx);
-    _LOG(tfd, only_in_tombstone, "    esi %08x  edi %08x\n",
+    _LOG(log, only_in_tombstone, "    esi %08x  edi %08x\n",
          r.esi, r.edi);
-    _LOG(tfd, only_in_tombstone, "    xcs %08x  xds %08x  xes %08x  xfs %08x  xss %08x\n",
+    _LOG(log, only_in_tombstone, "    xcs %08x  xds %08x  xes %08x  xfs %08x  xss %08x\n",
          r.xcs, r.xds, r.xes, r.xfs, r.xss);
-    _LOG(tfd, only_in_tombstone, "    eip %08x  ebp %08x  esp %08x  flags %08x\n",
+    _LOG(log, only_in_tombstone, "    eip %08x  ebp %08x  esp %08x  flags %08x\n",
          r.eip, r.ebp, r.esp, r.eflags);
 }
-
-void dump_thread(const ptrace_context_t* context, int tfd, pid_t tid, bool at_fault) {
-    dump_registers(context, tfd, tid, at_fault);
-
-    dump_backtrace_and_stack(context, tfd, tid, at_fault);
-
-    if (at_fault) {
-        dump_nearby_maps(context, tfd, tid);
-    }
-}
-