X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=b77c6f6b9c8c1dcce7acea8d5bee7128f501ef6d;hb=ce337daa00e42d4f2d9a4d9ae0ed51b20249d924;hp=42b056d2f264aef11978ebf5ebeb8e48523dde69;hpb=b6a6cd703ffefa6352249fb01f4da28d85d17306;p=musl

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 42b056d2..b77c6f6b 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -423,6 +423,28 @@ static void reclaim_gaps(struct dso *dso)
 	}
 }
 
+static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
+{
+	char *q = mmap(p, n, prot, flags, fd, off);
+	if (q != MAP_FAILED || errno != EINVAL) return q;
+	/* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
+	if (flags & MAP_ANONYMOUS) {
+		memset(p, 0, n);
+		return p;
+	}
+	ssize_t r;
+	if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
+	for (q=p; n; q+=r, off+=r, n-=r) {
+		r = read(fd, q, n);
+		if (r < 0 && errno != EINTR) return MAP_FAILED;
+		if (!r) {
+			memset(q, 0, n);
+			break;
+		}
+	}
+	return p;
+}
+
 static void *map_library(int fd, struct dso *dso)
 {
 	Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
@@ -524,19 +546,20 @@ static void *map_library(int fd, struct dso *dso)
 		prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 			((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 			((ph->p_flags&PF_X) ? PROT_EXEC : 0));
-		if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
+		if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 			goto error;
 		if (ph->p_memsz > ph->p_filesz) {
 			size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 			size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 			memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
-			if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
+			if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
 				goto error;
 		}
 	}
 	for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 		if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
-			if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
+			if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
+			    && errno != ENOSYS)
 				goto error;
 			break;
 		}
@@ -927,7 +950,8 @@ static void reloc_all(struct dso *p)
 		do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 
 		if (head != &ldso && p->relro_start != p->relro_end &&
-		    mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
+		    mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ)
+		    && errno != ENOSYS) {
 			error("Error relocating %s: RELRO protection failed: %m",
 				p->name);
 			if (runtime) longjmp(*rtld_fail, 1);
@@ -1192,6 +1216,17 @@ _Noreturn void __dls3(size_t *sp)
 	char **argv_orig = argv;
 	char **envp = argv+argc+1;
 
+	/* Find aux vector just past environ[] and use it to initialize
+	 * global data that may be needed before we can make syscalls. */
+	__environ = envp;
+	for (i=argc+1; argv[i]; i++);
+	libc.auxv = auxv = (void *)(argv+i+1);
+	decode_vec(auxv, aux, AUX_CNT);
+	__hwcap = aux[AT_HWCAP];
+	libc.page_size = aux[AT_PAGESZ];
+	libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
+		|| aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
+
 	/* Setup early thread pointer in builtin_tls for ldso/libc itself to
 	 * use during dynamic linking. If possible it will also serve as the
 	 * thread pointer at runtime. */
@@ -1200,25 +1235,11 @@ _Noreturn void __dls3(size_t *sp)
 		a_crash();
 	}
 
-	/* Find aux vector just past environ[] */
-	for (i=argc+1; argv[i]; i++)
-		if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
-			env_path = argv[i]+16;
-		else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
-			env_preload = argv[i]+11;
-	auxv = (void *)(argv+i+1);
-
-	decode_vec(auxv, aux, AUX_CNT);
-
 	/* Only trust user/env if kernel says we're not suid/sgid */
-	if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
-	  || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
-		env_path = 0;
-		env_preload = 0;
-		libc.secure = 1;
+	if (!libc.secure) {
+		env_path = getenv("LD_LIBRARY_PATH");
+		env_preload = getenv("LD_PRELOAD");
 	}
-	libc.page_size = aux[AT_PAGESZ];
-	libc.auxv = auxv;
 
 	/* If the main program was already loaded by the kernel,
 	 * AT_PHDR will point to some location other than the dynamic