add system for resetting TLS to initial values

[musl] / src / env / __init_tls.c

diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c
index c71f49c..5c17681 100644 (file)
--- a/src/env/__init_tls.c
+++ b/src/env/__init_tls.c
@@ -1,34 +1,40 @@
 #include <elf.h>
 #include <limits.h>
+#include <sys/mman.h>
+#include <string.h>
 #include "pthread_impl.h"
 #include "libc.h"
 #include "atomic.h"
 
 #ifndef SHARED
 
-static void *image;
-static size_t len, size, align;
+struct tls_image {
+       void *image;
+       size_t len, size, align;
+} __static_tls ATTR_LIBC_VISIBILITY;
+
+#define T __static_tls
 
 void *__copy_tls(unsigned char *mem)
 {
        pthread_t td;
-       if (!image) return mem;
+       if (!T.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);
+       mem += -((uintptr_t)mem + sizeof(struct pthread)) & (T.align-1);
        td = (pthread_t)mem;
        mem += sizeof(struct pthread);
 #else
-       mem += __libc.tls_size - sizeof(struct pthread);
-       mem -= (uintptr_t)mem & (align-1);
+       mem += libc.tls_size - sizeof(struct pthread);
+       mem -= (uintptr_t)mem & (T.align-1);
        td = (pthread_t)mem;
-       td->dtv = dtv;
-       mem -= size;
+       mem -= T.size;
 #endif
+       td->dtv = dtv;
        dtv[1] = mem;
-       memcpy(mem, image, len);
+       memcpy(mem, T.image, T.len);
        return td;
 }
 
@@ -71,15 +77,15 @@ void __init_tls(size_t *aux)
        }
        if (!tls_phdr) return;
 
-       image = (void *)(base + tls_phdr->p_vaddr);
-       len = tls_phdr->p_filesz;
-       size = tls_phdr->p_memsz;
-       align = tls_phdr->p_align;
+       T.image = (void *)(base + tls_phdr->p_vaddr);
+       T.len = tls_phdr->p_filesz;
+       T.size = tls_phdr->p_memsz;
+       T.align = tls_phdr->p_align;
 
-       size += (-size - (uintptr_t)image) & (align-1);
-       if (align < 4*sizeof(size_t)) align = 4*sizeof(size_t);
+       T.size += (-T.size - (uintptr_t)T.image) & (T.align-1);
+       if (T.align < 4*sizeof(size_t)) T.align = 4*sizeof(size_t);
 
-       libc.tls_size = 2*sizeof(void *)+size+align+sizeof(struct pthread);
+       libc.tls_size = 2*sizeof(void *)+T.size+T.align+sizeof(struct pthread);
 
        mem = __mmap(0, libc.tls_size, PROT_READ|PROT_WRITE,
                MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);