diff options
Diffstat (limited to 'src/env')
| -rw-r--r-- | src/env/__init_tls.c | 71 | ||||
| -rw-r--r-- | src/env/__libc_start_main.c | 2 |
2 files changed, 73 insertions, 0 deletions
diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c new file mode 100644 index 00000000..4a840cf2 --- /dev/null +++ b/src/env/__init_tls.c @@ -0,0 +1,71 @@ +#include <elf.h> +#include <limits.h> +#include "pthread_impl.h" +#include "libc.h" +#include "atomic.h" + +#ifndef SHARED + +static void *image; +static size_t len, bss, align; + +void *__copy_tls(unsigned char *mem, size_t cnt) +{ + mem += ((uintptr_t)image - (uintptr_t)mem) & (align-1); + memcpy(mem, image, len); + return mem + len + bss; +} + +static void *simple(void *p) +{ + *(void **)p = p; + return __set_thread_area(p) ? 0 : p; +} + +weak_alias(simple, __install_initial_tls); + +void *__mmap(void *, size_t, int, int, int, off_t); + +#if ULONG_MAX == 0xffffffff +typedef Elf32_Phdr Phdr; +#else +typedef Elf64_Phdr Phdr; +#endif + +#define AUX_CNT 6 + +void __init_tls(size_t *auxv) +{ + size_t i, aux[AUX_CNT] = { 0 }; + unsigned char *p, *mem; + size_t n, d; + Phdr *phdr, *tls_phdr=0; + size_t base = 0; + + for (; auxv[0]; auxv+=2) if (auxv[0]<AUX_CNT) aux[auxv[0]] = auxv[1]; + p = (void *)aux[AT_PHDR]; + for (p=(void *)aux[AT_PHDR]; aux[AT_PHNUM]--; p+=aux[AT_PHENT]) { + phdr = (void *)p; + if (phdr->p_type == PT_PHDR) + base = aux[AT_PHDR] - phdr->p_vaddr; + if (phdr->p_type == PT_TLS) + tls_phdr = phdr; + } + if (!tls_phdr) return; + + libc.tls_size = len+bss+align+4*sizeof(size_t)+sizeof(struct pthread); + + image = (void *)(base + tls_phdr->p_vaddr); + len = tls_phdr->p_filesz; + bss = tls_phdr->p_memsz - len; + align = tls_phdr->p_align; + if (align < 4*sizeof(size_t)) align = 4*sizeof(size_t); + mem = __mmap(0, libc.tls_size, PROT_READ|PROT_WRITE, + MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); + if (mem == MAP_FAILED) a_crash(); + + if (!__install_initial_tls(__copy_tls(mem, 0))) a_crash(); +} +#else +void __init_tls(size_t *auxv) { } +#endif diff --git a/src/env/__libc_start_main.c b/src/env/__libc_start_main.c index f31222b2..a38569d5 100644 --- a/src/env/__libc_start_main.c +++ b/src/env/__libc_start_main.c @@ -1,5 +1,6 @@ #include "libc.h" +void __init_tls(size_t *); void __init_security(size_t *); int __libc_start_main( @@ -15,6 +16,7 @@ int __libc_start_main( libc.ldso_fini = ldso_fini; libc.fini = fini; + __init_tls((void *)auxv); __init_security((void *)auxv); /* Execute constructors (static) linked into the application */ |