| commit | 50caca1a70a5f1f9dfba401f114bed0e721bbb0f | |
| author | Matthew Dillon <dillon@apollo.backplane.com> | |
| Sun, 12 May 2019 04:01:55 +0000 (11 21:01 -0700) | ||
| committer | Matthew Dillon <dillon@apollo.backplane.com> | |
| Sun, 12 May 2019 04:07:40 +0000 (11 21:07 -0700) | ||
| tree | dbf2c8c6f2dd27015c27b89411d972b90a0d032c | treesnapshot (tar.gz zip) |
| parent | 5b329e620879c577bf125590808f5146f61a19bb | commitdiff |
rtld-elf - Notify thread state to optimize relocations
* Add shims to allow libthread_xu to notify rtld when threading
is being used.
* Requires weak symbols in libc which are overriden by rtld-elf.
* Implement the feature in rtld-elf and use it to avoid making calls
to lwp_gettid(). When threaded, use tls_get_tcb() (which does not
require a system call) instead of lwp_gettid(). When not threaded,
just use a constant.
NOTE: We cannot use tls_get_tcb() unconditionally because the tcb
is not setup during early relocations. So do this whack-a-mole
to make it work.
* This leaves just the sigprocmask wrappers around rtld-elf (which
are needed to prevent stacked relocations from signal handlers).
Poked-by: mjg
* Add shims to allow libthread_xu to notify rtld when threading
is being used.
* Requires weak symbols in libc which are overriden by rtld-elf.
* Implement the feature in rtld-elf and use it to avoid making calls
to lwp_gettid(). When threaded, use tls_get_tcb() (which does not
require a system call) instead of lwp_gettid(). When not threaded,
just use a constant.
NOTE: We cannot use tls_get_tcb() unconditionally because the tcb
is not setup during early relocations. So do this whack-a-mole
to make it work.
* This leaves just the sigprocmask wrappers around rtld-elf (which
are needed to prevent stacked relocations from signal handlers).
Poked-by: mjg