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author | Rich Felker <dalias@aerifal.cx> | 2012-10-15 18:51:53 -0400 |
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committer | Rich Felker <dalias@aerifal.cx> | 2012-10-15 18:51:53 -0400 |
commit | 9ec4283b28cf676292fd5c6f681bef1e90e30c18 (patch) | |
tree | 2897be56744c39158a3e53adfc4e3569b3f8547d /src/env | |
parent | d5304147b983f309ed0c9050e3b8b6f2c9f87f43 (diff) | |
download | musl-9ec4283b28cf676292fd5c6f681bef1e90e30c18.tar.gz musl-9ec4283b28cf676292fd5c6f681bef1e90e30c18.tar.xz musl-9ec4283b28cf676292fd5c6f681bef1e90e30c18.zip |
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.
Diffstat (limited to 'src/env')
-rw-r--r-- | src/env/__init_tls.c | 9 |
1 files changed, 8 insertions, 1 deletions
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); |