X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fenv%2F__init_tls.c;h=73551e6c4173af5976c3084a728efc4707d8e0a3;hb=cd7159e7be73451befedce2e9dfd9f6a4c3b21f0;hp=b19bdb6493a3c00e6e646c9c9d13d9e0ea46de56;hpb=dcd60371500a74d489372cac7240674c992c2484;p=musl

diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c
index b19bdb64..73551e6c 100644
--- a/src/env/__init_tls.c
+++ b/src/env/__init_tls.c
@@ -1,31 +1,67 @@
 #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)
+static
+#endif
+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)
-{
-	*(void **)p = p;
-	return __set_thread_area(p) ? 0 : p;
-}
+#ifndef SHARED
+
+static struct builtin_tls {
+	char c;
+	struct pthread pt;
+	void *space[16];
+} builtin_tls[1];
+#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 
-weak_alias(simple, __install_initial_tls);
+struct tls_image {
+	void *image;
+	size_t len, size, align;
+} __static_tls;
 
-void *__mmap(void *, size_t, int, int, int, off_t);
+#define T __static_tls
+
+void *__copy_tls(unsigned char *mem)
+{
+	pthread_t td;
+	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)) & (T.align-1);
+	td = (pthread_t)mem;
+	mem += sizeof(struct pthread);
+#else
+	mem += libc.tls_size - sizeof(struct pthread);
+	mem -= (uintptr_t)mem & (T.align-1);
+	td = (pthread_t)mem;
+	mem -= T.size;
+#endif
+	td->dtv = td->dtv_copy = dtv;
+	dtv[1] = mem;
+	memcpy(mem, T.image, T.len);
+	return td;
+}
 
 #if ULONG_MAX == 0xffffffff
 typedef Elf32_Phdr Phdr;
@@ -33,38 +69,53 @@ typedef Elf32_Phdr Phdr;
 typedef Elf64_Phdr Phdr;
 #endif
 
-#define AUX_CNT 6
-
-void __init_tls(size_t *auxv)
+void __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_TLS)
 			tls_phdr = phdr;
 	}
-	if (!tls_phdr) return;
 
-	libc.tls_size = size+align+8*sizeof(size_t)+sizeof(struct pthread);
+	if (tls_phdr) {
+		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;
+	}
+
+	T.size += (-T.size - (uintptr_t)T.image) & (T.align-1);
+	if (T.align < MIN_TLS_ALIGN) T.align = MIN_TLS_ALIGN;
+
+	libc.tls_size = 2*sizeof(void *)+T.size+T.align+sizeof(struct pthread)
+		+ MIN_TLS_ALIGN-1 & -MIN_TLS_ALIGN;
 
-	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();
+	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;
+	}
 
-	if (!__install_initial_tls(__copy_tls(mem))) a_crash();
+	/* Failure to initialize thread pointer is always fatal. */
+	if (__init_tp(__copy_tls(mem)) < 0)
+		a_crash();
 }
 #else
 void __init_tls(size_t *auxv) { }