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| author | Tom Tromey <tromey@adacore.com> | 2023-09-08 08:25:15 -0600 |
|---|---|---|
| committer | Tom Tromey <tromey@adacore.com> | 2023-12-01 10:36:00 -0700 |
| commit | c6f7f9c80c3b92c6d877214d38aaef141adc5b93 (patch) | |
| tree | 243638f58de9fe248d6193ffffa913a0ab25ae38 /gdbserver | |
| parent | 596cd22cb10519f9baad6295fed13443d1ef86f9 (diff) | |
| download | gdb-c6f7f9c80c3b92c6d877214d38aaef141adc5b93.zip gdb-c6f7f9c80c3b92c6d877214d38aaef141adc5b93.tar.gz gdb-c6f7f9c80c3b92c6d877214d38aaef141adc5b93.tar.bz2 | |
Bail out of "attach" if a thread cannot be traced
On Linux, threads are treated much like separate processes by the
kernel. In particular, it's possible to ptrace just a single thread.
If gdb tries to attach to a multi-threaded inferior, where a non-main
thread is already being traced (e.g., by strace), then gdb will get
into an infinite loop attempting to attach.
This patch fixes this problem by having the attach fail if ptrace
fails to attach to any thread of the inferior.
Diffstat (limited to 'gdbserver')
| -rw-r--r-- | gdbserver/linux-low.cc | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc index eea2d8a..4aa011c 100644 --- a/gdbserver/linux-low.cc +++ b/gdbserver/linux-low.cc @@ -1154,7 +1154,7 @@ attach_proc_task_lwp_callback (ptid_t ptid) std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err); - warning (_("Cannot attach to lwp %d: %s"), lwpid, reason.c_str ()); + error (_("Cannot attach to lwp %d: %s"), lwpid, reason.c_str ()); } return 1; @@ -1207,7 +1207,18 @@ linux_process_target::attach (unsigned long pid) threads/LWPs, and those structures may well be corrupted. Note that once thread_db is loaded, we'll still use it to list threads and associate pthread info with each LWP. */ - linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); + try + { + linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); + } + catch (const gdb_exception_error &) + { + /* Make sure we do not deliver the SIGSTOP to the process. */ + initial_thread->last_resume_kind = resume_continue; + + this->detach (proc); + throw; + } /* GDB will shortly read the xml target description for this process, to figure out the process' architecture. But the target |