From 9ec4283b28cf676292fd5c6f681bef1e90e30c18 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Mon, 15 Oct 2012 18:51:53 -0400 Subject: add support for TLS variant I, presently needed for arm and mips despite documentation that makes it sound a lot different, the only ABI-constraint difference between TLS variants II and I seems to be that variant II stores the initial TLS segment immediately below the thread pointer (i.e. the thread pointer points to the end of it) and variant I stores the initial TLS segment above the thread pointer, requiring the thread descriptor to be stored below. the actual value stored in the thread pointer register also tends to have per-arch random offsets applied to it for silly micro-optimization purposes. with these changes applied, TLS should be basically working on all supported archs except microblaze. I'm still working on getting the necessary information and a working toolchain that can build TLS binaries for microblaze, but in theory, static-linked programs with TLS and dynamic-linked programs where only the main executable uses TLS should already work on microblaze. alignment constraints have not yet been heavily tested, so it's possible that this code does not always align TLS segments correctly on archs that need TLS variant I. --- src/env/__init_tls.c | 9 ++++++++- src/ldso/dynlink.c | 35 ++++++++++++++++++++++++++++++++--- src/thread/arm/tls.s | 4 ++++ src/thread/pthread_create.c | 2 +- src/thread/pthread_self.c | 2 +- 5 files changed, 46 insertions(+), 6 deletions(-) create mode 100644 src/thread/arm/tls.s (limited to 'src') diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c index e70025d7..ab5992ce 100644 --- a/src/env/__init_tls.c +++ b/src/env/__init_tls.c @@ -15,11 +15,18 @@ void *__copy_tls(unsigned char *mem) if (!image) return mem; void **dtv = (void *)mem; dtv[0] = (void *)1; +#ifdef TLS_ABOVE_TP + mem += sizeof(void *) * 2; + mem += -((uintptr_t)mem + sizeof(struct pthread)) & (align-1); + td = (pthread_t)mem; + mem += sizeof(struct pthread); +#else mem += __libc.tls_size - sizeof(struct pthread); mem -= (uintptr_t)mem & (align-1); td = (pthread_t)mem; td->dtv = dtv; mem -= size; +#endif dtv[1] = mem; memcpy(mem, image, len); return td; @@ -33,7 +40,7 @@ void *__tls_get_addr(size_t *v) static void *simple(void *p) { *(void **)p = p; - return __set_thread_area(p) ? 0 : p; + return __set_thread_area(TP_ADJ(p)) ? 0 : p; } weak_alias(simple, __install_initial_tls); diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 5353979e..2ec8fb8c 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -539,10 +539,16 @@ static struct dso *load_library(const char *name) } p->tls_id = ++tls_cnt; tls_align = MAXP2(tls_align, p->tls_align); +#ifdef TLS_ABOVE_TP + p->tls_offset = tls_offset + ( (tls_align-1) & + -(tls_offset + (uintptr_t)p->tls_image) ); + tls_offset += p->tls_size; +#else tls_offset += p->tls_size + p->tls_align - 1; tls_offset -= (tls_offset + (uintptr_t)p->tls_image) & (p->tls_align-1); p->tls_offset = tls_offset; +#endif p->new_dtv = (void *)(-sizeof(size_t) & (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t))); p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1)); @@ -697,6 +703,18 @@ void *__copy_tls(unsigned char *mem) void **dtv = (void *)mem; dtv[0] = (void *)tls_cnt; +#ifdef TLS_ABOVE_TP + mem += sizeof(void *) * (tls_cnt+1); + mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1); + td = (pthread_t)mem; + mem += sizeof(struct pthread); + + for (p=head; p; p=p->next) { + if (!p->tls_id) continue; + dtv[p->tls_id] = mem + p->tls_offset; + memcpy(dtv[p->tls_id], p->tls_image, p->tls_len); + } +#else mem += libc.tls_size - sizeof(struct pthread); mem -= (uintptr_t)mem & (tls_align-1); td = (pthread_t)mem; @@ -706,6 +724,7 @@ void *__copy_tls(unsigned char *mem) dtv[p->tls_id] = mem - p->tls_offset; memcpy(dtv[p->tls_id], p->tls_image, p->tls_len); } +#endif td->dtv = dtv; return td; } @@ -753,9 +772,12 @@ void *__tls_get_addr(size_t *v) static void update_tls_size() { - size_t below_tp = (1+tls_cnt) * sizeof(void *) + tls_offset; - size_t above_tp = sizeof(struct pthread) + tls_align; - libc.tls_size = ALIGN(below_tp + above_tp, tls_align); + libc.tls_size = ALIGN( + (1+tls_cnt) * sizeof(void *) + + tls_offset + + sizeof(struct pthread) + + tls_align * 2, + tls_align); } void *__dynlink(int argc, char **argv) @@ -866,9 +888,16 @@ void *__dynlink(int argc, char **argv) } if (app->tls_size) { app->tls_id = tls_cnt = 1; +#ifdef TLS_ABOVE_TP + app->tls_offset = 0; + tls_offset = app->tls_size + + ( -((uintptr_t)app->tls_image + app->tls_size) + & (app->tls_align-1) ); +#else tls_offset = app->tls_offset = app->tls_size + ( -((uintptr_t)app->tls_image + app->tls_size) & (app->tls_align-1) ); +#endif tls_align = MAXP2(tls_align, app->tls_align); } app->global = 1; diff --git a/src/thread/arm/tls.s b/src/thread/arm/tls.s new file mode 100644 index 00000000..59736ac2 --- /dev/null +++ b/src/thread/arm/tls.s @@ -0,0 +1,4 @@ +.global __aeabi_read_tp +.type __aeabi_read_tp,%function +__aeabi_read_tp: + ldr pc,=0xffff0fe0 diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index 627ff5fb..e67616e7 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -147,7 +147,7 @@ int pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attr, new->canary = self->canary; a_inc(&libc.threads_minus_1); - ret = __clone(start, stack, flags, new, &new->tid, new, &new->tid); + ret = __clone(start, stack, flags, new, &new->tid, TP_ADJ(new), &new->tid); __release_ptc(); diff --git a/src/thread/pthread_self.c b/src/thread/pthread_self.c index a93d8129..23dbaa5e 100644 --- a/src/thread/pthread_self.c +++ b/src/thread/pthread_self.c @@ -10,7 +10,7 @@ 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; + if (__set_thread_area(TP_ADJ(main_thread)) < 0) return -1; main_thread->canceldisable = libc.canceldisable; main_thread->tsd = (void **)__pthread_tsd_main; main_thread->errno_ptr = __errno_location(); -- cgit v1.2.1