diff options
Diffstat (limited to 'debuggerd/debuggerd.c')
| -rw-r--r-- | debuggerd/debuggerd.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/debuggerd/debuggerd.c b/debuggerd/debuggerd.c index 5fa4442..7a3e781 100644 --- a/debuggerd/debuggerd.c +++ b/debuggerd/debuggerd.c @@ -642,7 +642,7 @@ static void handle_crashing_process(int fd) goto done; } - sprintf(buf,"/proc/%d/task/%d", cr.pid, tid); + snprintf(buf, sizeof buf, "/proc/%d/task/%d", cr.pid, tid); if(stat(buf, &s)) { LOG("tid %d does not exist in pid %d. ignoring debug request\n", tid, cr.pid); @@ -652,7 +652,19 @@ static void handle_crashing_process(int fd) XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n", cr.pid, cr.uid, cr.gid, tid); + /* Note that at this point, the target thread's signal handler + * is blocked in a read() call. This gives us the time to PTRACE_ATTACH + * to it before it has a chance to really fault. + * + * After the attach, the thread is stopped, and we write to the file + * descriptor to ensure that it will run as soon as we call PTRACE_CONT + * below. See details in bionic/libc/linker/debugger.c, in function + * debugger_signal_handler(). + */ tid_attach_status = ptrace(PTRACE_ATTACH, tid, 0, 0); + + TEMP_FAILURE_RETRY(write(fd, &tid, 1)); + if(tid_attach_status < 0) { LOG("ptrace attach failed: %s\n", strerror(errno)); goto done; |