diff options
Diffstat (limited to 'rda/unix/thread-db.c')
| -rw-r--r-- | rda/unix/thread-db.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/rda/unix/thread-db.c b/rda/unix/thread-db.c index 7a0bba426db..751431226c0 100644 --- a/rda/unix/thread-db.c +++ b/rda/unix/thread-db.c @@ -2662,6 +2662,36 @@ thread_db_attach (struct gdbserv *serv, struct gdbserv_target *target) else fprintf (stderr, "< ERROR attach: GDB will not read thread regs. >>>\n"); + /* Preload the symbol list with the names of the symbols whose names + we use ourselves. + + This might be a kludge, but it's not a gratuitous kludge. On + older LinuxThreads libraries, RDA must manage LinuxThreads + signals. Since libthread_db provides no abstraction for managing + them, RDA must look up the addresses of the signal variables and + read their values itself. However, libthread_db may never look + those symbols up itself, and they may not appear in the list + provided by td_symbol_list_p. (In fact, in glibc-2.2.93, they + don't.) + + So RDA may as well preload them into the symbol list; otherwise, + get_thread_signals will fail even though the symbols are defined, + because the names will only get added to symbol_list as we + attempt to look them up; each remote protocol symbol lookup dance + will resolve exactly one new symbol, allowing get_thread_signal + to get as far as requesting the next one and failing. + + As it turns out, this is actually necessary, not just efficient, + because failures from get_thread_signal cause RDA to try the + libthread_db event-based interface; we may end up using that even + when the signal-based interface is actually available. And we'd + rather use the signal-based interface when we can, to avoid + changing the behavior of RDA on older systems. */ + add_symbol_to_list ("__pthread_sig_restart", 0, UNDEFINED); + add_symbol_to_list ("__pthread_sig_cancel", 0, UNDEFINED); + add_symbol_to_list ("__pthread_sig_debug", 0, UNDEFINED); + add_symbol_to_list ("__pthread_threads_debug", 0, UNDEFINED); + if (td_symbol_list_p) { /* Take all the symbol names libthread_db might try to look up @@ -2673,17 +2703,6 @@ thread_db_attach (struct gdbserv *serv, struct gdbserv_target *target) for (i = 0; symbol_list[i]; i++) add_symbol_to_list (symbol_list[i], 0, UNDEFINED); } - else - { - /* KLUDGE: Insert some magic symbols into the cached symbol list, - to be looked up later. This is badly wrong -- we should be - obtaining these values thru the thread_db interface. Their names - should not be hard-coded here <sob>. */ - add_symbol_to_list ("__pthread_sig_restart", 0, UNDEFINED); - add_symbol_to_list ("__pthread_sig_cancel", 0, UNDEFINED); - add_symbol_to_list ("__pthread_sig_debug", 0, UNDEFINED); - add_symbol_to_list ("__pthread_threads_debug", 0, UNDEFINED); - } /* Attempt to open the thread_db interface. This attempt will most likely fail (unles the child is statically linked). */ |