X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fenv%2F__init_tls.c;h=b125eb1f543abd34b28524019bd7b8043977b1ca;hb=1f53e7d00c375efb32e2e468f91a42668653d5f0;hp=aff388bda36cd6862cf4a487df44e5bd3c5574d1;hpb=bc6a35fb7b02f068b901f22a56559996395cfd3b;p=musl

diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c
index aff388bd..b125eb1f 100644
--- a/src/env/__init_tls.c
+++ b/src/env/__init_tls.c
@@ -1,31 +1,69 @@
 #include <elf.h>
 #include <limits.h>
+#include <sys/mman.h>
+#include <string.h>
+#include <stddef.h>
 #include "pthread_impl.h"
 #include "libc.h"
 #include "atomic.h"
+#include "syscall.h"
 
-#ifndef SHARED
-
-static void *image;
-static size_t len, size, align;
-
-void *__copy_tls(unsigned char *mem, size_t cnt)
+int __init_tp(void *p)
 {
-	mem += -size & (4*sizeof(size_t)-1);
-	mem += ((uintptr_t)image - (uintptr_t)mem) & (align-1);
-	memcpy(mem, image, len);
-	return mem + size;
+	pthread_t td = p;
+	td->self = td;
+	int r = __set_thread_area(TP_ADJ(p));
+	if (r < 0) return -1;
+	if (!r) libc.can_do_threads = 1;
+	td->tid = __syscall(SYS_set_tid_address, &td->tid);
+	td->locale = &libc.global_locale;
+	td->robust_list.head = &td->robust_list.head;
+	return 0;
 }
 
-static void *simple(void *p)
+static struct builtin_tls {
+	char c;
+	struct pthread pt;
+	void *space[16];
+} builtin_tls[1];
+#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
+
+static struct tls_module main_tls;
+
+void *__copy_tls(unsigned char *mem)
 {
-	*(void **)p = p;
-	return __set_thread_area(p) ? 0 : p;
-}
+	pthread_t td;
+	struct tls_module *p;
+	size_t i;
+	void **dtv;
+
+#ifdef TLS_ABOVE_TP
+	dtv = (void **)(mem + libc.tls_size) - (libc.tls_cnt + 1);
 
-weak_alias(simple, __install_initial_tls);
+	mem += -((uintptr_t)mem + sizeof(struct pthread)) & (libc.tls_align-1);
+	td = (pthread_t)mem;
+	mem += sizeof(struct pthread);
 
-void *__mmap(void *, size_t, int, int, int, off_t);
+	for (i=1, p=libc.tls_head; p; i++, p=p->next) {
+		dtv[i] = mem + p->offset;
+		memcpy(dtv[i], p->image, p->len);
+	}
+#else
+	dtv = (void **)mem;
+
+	mem += libc.tls_size - sizeof(struct pthread);
+	mem -= (uintptr_t)mem & (libc.tls_align-1);
+	td = (pthread_t)mem;
+
+	for (i=1, p=libc.tls_head; p; i++, p=p->next) {
+		dtv[i] = mem - p->offset;
+		memcpy(dtv[i], p->image, p->len);
+	}
+#endif
+	dtv[0] = (void *)libc.tls_cnt;
+	td->dtv = td->dtv_copy = dtv;
+	return td;
+}
 
 #if ULONG_MAX == 0xffffffff
 typedef Elf32_Phdr Phdr;
@@ -33,39 +71,66 @@ typedef Elf32_Phdr Phdr;
 typedef Elf64_Phdr Phdr;
 #endif
 
-#define AUX_CNT 6
+__attribute__((__weak__, __visibility__("hidden")))
+extern const size_t _DYNAMIC[];
 
-void __init_tls(size_t *auxv)
+static void static_init_tls(size_t *aux)
 {
-	size_t i, aux[AUX_CNT] = { 0 };
-	unsigned char *p, *mem;
-	size_t n, d;
+	unsigned char *p;
+	size_t n;
 	Phdr *phdr, *tls_phdr=0;
 	size_t base = 0;
+	void *mem;
 
-	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]) {
+	for (p=(void *)aux[AT_PHDR],n=aux[AT_PHNUM]; n; n--,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_DYNAMIC && _DYNAMIC)
+			base = (size_t)_DYNAMIC - phdr->p_vaddr;
 		if (phdr->p_type == PT_TLS)
 			tls_phdr = phdr;
 	}
-	if (!tls_phdr) return;
 
-	libc.tls_size = size+align+8*sizeof(size_t)+sizeof(struct pthread);
+	if (tls_phdr) {
+		main_tls.image = (void *)(base + tls_phdr->p_vaddr);
+		main_tls.len = tls_phdr->p_filesz;
+		main_tls.size = tls_phdr->p_memsz;
+		main_tls.align = tls_phdr->p_align;
+		libc.tls_cnt = 1;
+		libc.tls_head = &main_tls;
+	}
 
-	image = (void *)(base + tls_phdr->p_vaddr);
-	len = tls_phdr->p_filesz;
-	size = tls_phdr->p_memsz;
-	align = tls_phdr->p_align;
-	mem = __mmap(0, libc.tls_size, PROT_READ|PROT_WRITE,
-		MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-	if (mem == MAP_FAILED) a_crash();
+	main_tls.size += (-main_tls.size - (uintptr_t)main_tls.image)
+		& (main_tls.align-1);
+	if (main_tls.align < MIN_TLS_ALIGN) main_tls.align = MIN_TLS_ALIGN;
+#ifndef TLS_ABOVE_TP
+	main_tls.offset = main_tls.size;
+#endif
 
-	if (!__install_initial_tls(__copy_tls(mem, 0))) a_crash();
-}
-#else
-void __init_tls(size_t *auxv) { }
+	libc.tls_align = main_tls.align;
+	libc.tls_size = 2*sizeof(void *) + sizeof(struct pthread)
+		+ main_tls.size + main_tls.align
+		+ MIN_TLS_ALIGN-1 & -MIN_TLS_ALIGN;
+
+	if (libc.tls_size > sizeof builtin_tls) {
+#ifndef SYS_mmap2
+#define SYS_mmap2 SYS_mmap
 #endif
+		mem = (void *)__syscall(
+			SYS_mmap2,
+			0, libc.tls_size, PROT_READ|PROT_WRITE,
+			MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+		/* -4095...-1 cast to void * will crash on dereference anyway,
+		 * so don't bloat the init code checking for error codes and
+		 * explicitly calling a_crash(). */
+	} else {
+		mem = builtin_tls;
+	}
+
+	/* Failure to initialize thread pointer is always fatal. */
+	if (__init_tp(__copy_tls(mem)) < 0)
+		a_crash();
+}
+
+weak_alias(static_init_tls, __init_tls);