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Commit 4bb47720 authored by Kévin PETIT's avatar Kévin PETIT Committed by Elliott Hughes
Browse files

debuggerd: a few generic improvements 



This one makes dump_memory reasonably architecture-agnostic so it is
possible to share the code between architectures.

It also includes a few small improvements in tombstone.cpp.

Change-Id: Ib8a9599bfa420b41e80207988e87aee1b9d79541
Signed-off-by: default avatarKévin PETIT <kevin.petit@arm.com>
parent caefe564

debuggerd/arm/machine.cpp

+0 −59
Original line number Diff line number Diff line
@@ -38,65 +38,6 @@ 
#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, reinterpret_cast<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) {

debuggerd/mips/machine.cpp

+0 −55
Original line number Diff line number Diff line
@@ -34,61 +34,6 @@ 


#define R(x) (static_cast<unsigned int>(x))



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;

  }

  end = p + 80;

  // 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);



      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++ = '.';

        }

      }

      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) {

debuggerd/tombstone.cpp

+18 −14
Original line number Diff line number Diff line
@@ -14,18 +14,20 @@ 
 * limitations under the License.

 */



#include <dirent.h>

#include <errno.h>

#include <fcntl.h>

#include <inttypes.h>

#include <signal.h>

#include <stddef.h>

#include <stdio.h>

#include <stdlib.h>

#include <signal.h>

#include <string.h>

#include <stdio.h>

#include <fcntl.h>

#include <errno.h>

#include <dirent.h>

#include <time.h>

#include <sys/ptrace.h>

#include <sys/socket.h>

#include <sys/stat.h>

#include <inttypes.h>

#include <sys/un.h>



#include <private/android_filesystem_config.h>
@@ -36,9 +38,6 @@ 
#include <backtrace/Backtrace.h>

#include <backtrace/BacktraceMap.h>



#include <sys/socket.h>

#include <linux/un.h>



#include <selinux/android.h>



#include <UniquePtr.h>
@@ -51,6 +50,7 @@ 


#define MAX_TOMBSTONES  10

#define TOMBSTONE_DIR   "/data/tombstones"

#define TOMBSTONE_TEMPLATE (TOMBSTONE_DIR"/tombstone_%02d")



// Must match the path defined in NativeCrashListener.java

#define NCRASH_SOCKET_PATH "/data/system/ndebugsocket"
@@ -60,7 +60,6 @@ 
  typeof(y) __dummy2;     \

  (void)(&__dummy1 == &__dummy2); }





static bool signal_has_address(int sig) {

  switch (sig) {

    case SIGILL:
@@ -675,7 +674,7 @@ static char* find_and_open_tombstone(int* fd) { 
  char path[128];

  int oldest = 0;

  for (int i = 0; i < MAX_TOMBSTONES; i++) {

    snprintf(path, sizeof(path), TOMBSTONE_DIR"/tombstone_%02d", i);

    snprintf(path, sizeof(path), TOMBSTONE_TEMPLATE, i);



    if (!stat(path, &sb)) {

      if (sb.st_mtime < mtime) {
@@ -696,7 +695,7 @@ static char* find_and_open_tombstone(int* fd) { 
  }



  // we didn't find an available file, so we clobber the oldest one

  snprintf(path, sizeof(path), TOMBSTONE_DIR"/tombstone_%02d", oldest);

  snprintf(path, sizeof(path), TOMBSTONE_TEMPLATE, oldest);

  *fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);

  if (*fd < 0) {

    LOG("failed to open tombstone file '%s': %s\n", path, strerror(errno));
@@ -739,8 +738,13 @@ static int activity_manager_connect() { 
char* engrave_tombstone(

    pid_t pid, pid_t tid, int signal, uintptr_t abort_msg_address, bool dump_sibling_threads,

    bool quiet, bool* detach_failed, int* total_sleep_time_usec) {

  mkdir(TOMBSTONE_DIR, 0755);

  chown(TOMBSTONE_DIR, AID_SYSTEM, AID_SYSTEM);

  if ((mkdir(TOMBSTONE_DIR, 0755) == -1) && (errno != EEXIST)) {

      LOG("failed to create %s: %s\n", TOMBSTONE_DIR, strerror(errno));

  }



  if (chown(TOMBSTONE_DIR, AID_SYSTEM, AID_SYSTEM) == -1) {

      LOG("failed to change ownership of %s: %s\n", TOMBSTONE_DIR, strerror(errno));

  }



  if (selinux_android_restorecon(TOMBSTONE_DIR) == -1) {

    *detach_failed = false;

debuggerd/utility.cpp

+74 −0
Original line number Diff line number Diff line
@@ -127,3 +127,77 @@ void wait_for_stop(pid_t tid, int* total_sleep_time_usec) { 
    *total_sleep_time_usec += sleep_time_usec;

  }

}



#if defined (__mips__)

#define DUMP_MEMORY_AS_ASCII 1

#else

#define DUMP_MEMORY_AS_ASCII 0

#endif



void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags) {

    char code_buffer[64];

    char ascii_buffer[32];

    uintptr_t p, end;



    p = addr & ~(sizeof(long) - 1);

    /* Dump 32 bytes before addr */

    p -= 32;

    if (p > addr) {

        /* catch underflow */

        p = 0;

    }

    /* Dump 256 bytes */

    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

     *  0000000000008d34 ef000000e8bd0090 e1b00000512fff1e  ............../Q

     *  0000000000008d44 ea00b1f9e92d0090 e3a070fcef000000  ......-..p......

     * On 32-bit machines, there are still 16 bytes per line but addresses and

     * words are of course presented differently.

     */

    while (p < end) {

        char* asc_out = ascii_buffer;



        int len = snprintf(code_buffer, sizeof(code_buffer), "%" PRIPTR " ", p);



        for (size_t i = 0; i < 16/sizeof(long); i++) {

            long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL);

            if (data == -1 && errno != 0) {

                // ptrace failed, probably because we're dumping memory in an

                // unmapped or inaccessible page.

#ifdef __LP64__

                len += sprintf(code_buffer + len, "---------------- ");

#else

                len += sprintf(code_buffer + len, "-------- ");

#endif

            } else {

                len += sprintf(code_buffer + len, "%" PRIPTR " ",

                               static_cast<uintptr_t>(data));

            }



#if DUMP_MEMORY_AS_ASCII

            for (size_t j = 0; j < sizeof(long); 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 += sizeof(long);

        }

        *asc_out = '\0';

        _LOG(log, scope_flags, "    %s %s\n", code_buffer, ascii_buffer);

    }

}

debuggerd/utility.h

+12 −1
Original line number Diff line number Diff line
@@ -18,8 +18,9 @@ 
#ifndef _DEBUGGERD_UTILITY_H

#define _DEBUGGERD_UTILITY_H



#include <stddef.h>

#include <inttypes.h>

#include <stdbool.h>

#include <stddef.h>



typedef struct {

    /* tombstone file descriptor */
@@ -60,7 +61,17 @@ void _LOG(log_t* log, int scopeFlags, const char *fmt, ...) 
#define XLOG2(fmt...) do {} while(0)

#endif



#if __LP64__

#define PRIPTR "016" PRIxPTR

typedef uint64_t word_t;

#else

#define PRIPTR "08" PRIxPTR

typedef uint32_t word_t;

#endif



int wait_for_signal(pid_t tid, int* total_sleep_time_usec);

void wait_for_stop(pid_t tid, int* total_sleep_time_usec);



void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags);



#endif // _DEBUGGERD_UTILITY_H