From 8431d7972fd9be0fdcaff8516316d748e81724bb Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 4 Oct 2012 16:35:46 -0400 Subject: TLS (GNU/C11 thread-local storage) support for static-linked programs the design for TLS in dynamic-linked programs is mostly complete too, but I have not yet implemented it. cost is nonzero but still low for programs which do not use TLS and/or do not use threads (a few hundred bytes of new code, plus dependency on memcpy). i believe it can be made smaller at some point by merging __init_tls and __init_security into __libc_start_main and avoiding duplicate auxv-parsing code. at the same time, I've also slightly changed the logic pthread_create uses to allocate guard pages to ensure that guard pages are not counted towards commit charge. --- src/thread/pthread_self.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'src/thread/pthread_self.c') diff --git a/src/thread/pthread_self.c b/src/thread/pthread_self.c index a8cc80b5..a93d8129 100644 --- a/src/thread/pthread_self.c +++ b/src/thread/pthread_self.c @@ -1,6 +1,6 @@ #include "pthread_impl.h" -static struct pthread main_thread; +static struct pthread *main_thread = &(struct pthread){0}; /* pthread_key_create.c overrides this */ static const void *dummy[1] = { 0 }; @@ -10,14 +10,14 @@ static int init_main_thread() { __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, SIGPT_SET, 0, __SYSCALL_SSLEN); - if (__set_thread_area(&main_thread) < 0) return -1; - main_thread.canceldisable = libc.canceldisable; - main_thread.tsd = (void **)__pthread_tsd_main; - main_thread.errno_ptr = __errno_location(); - main_thread.self = &main_thread; - main_thread.tid = main_thread.pid = - __syscall(SYS_set_tid_address, &main_thread.tid); - libc.main_thread = &main_thread; + if (__set_thread_area(main_thread) < 0) return -1; + main_thread->canceldisable = libc.canceldisable; + main_thread->tsd = (void **)__pthread_tsd_main; + main_thread->errno_ptr = __errno_location(); + main_thread->self = main_thread; + main_thread->tid = main_thread->pid = + __syscall(SYS_set_tid_address, &main_thread->tid); + libc.main_thread = main_thread; return 0; } @@ -35,3 +35,9 @@ pthread_t __pthread_self_def() weak_alias(__pthread_self_def, pthread_self); weak_alias(__pthread_self_def, __pthread_self_init); + +void *__install_initial_tls(void *p) +{ + main_thread = p; + return __pthread_self_def(); +} -- cgit v1.2.1