Module Name: src
Committed By: jakllsch
Date: Thu Sep 20 18:41:05 UTC 2018
Modified Files:
src/libexec/ld.elf_so/arch/aarch64: mdreloc.c rtld_start.S
Log Message:
Improve support for R_AARCH64_TLSDESC relocations.
In large part from FreeBSD.
To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 src/libexec/ld.elf_so/arch/aarch64/mdreloc.c
cvs rdiff -u -r1.2 -r1.3 src/libexec/ld.elf_so/arch/aarch64/rtld_start.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/libexec/ld.elf_so/arch/aarch64/mdreloc.c
diff -u src/libexec/ld.elf_so/arch/aarch64/mdreloc.c:1.8 src/libexec/ld.elf_so/arch/aarch64/mdreloc.c:1.9
--- src/libexec/ld.elf_so/arch/aarch64/mdreloc.c:1.8 Mon Jul 16 00:29:37 2018
+++ src/libexec/ld.elf_so/arch/aarch64/mdreloc.c Thu Sep 20 18:41:05 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: mdreloc.c,v 1.8 2018/07/16 00:29:37 christos Exp $ */
+/* $NetBSD: mdreloc.c,v 1.9 2018/09/20 18:41:05 jakllsch Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -29,9 +29,38 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
+/*-
+ * Copyright (c) 2014-2015 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Andrew Turner
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
#include <sys/cdefs.h>
#ifndef lint
-__RCSID("$NetBSD: mdreloc.c,v 1.8 2018/07/16 00:29:37 christos Exp $");
+__RCSID("$NetBSD: mdreloc.c,v 1.9 2018/09/20 18:41:05 jakllsch Exp $");
#endif /* not lint */
#include <sys/types.h>
@@ -40,10 +69,18 @@ __RCSID("$NetBSD: mdreloc.c,v 1.8 2018/0
#include "debug.h"
#include "rtld.h"
+struct tls_data {
+ int64_t index;
+ Obj_Entry *obj;
+ const Elf_Rela *rela;
+};
+
void _rtld_bind_start(void);
void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
Elf_Addr _rtld_bind(const Obj_Entry *, Elf_Word);
void *_rtld_tlsdesc(void *);
+void *_rtld_tlsdesc_dynamic(void *);
+int64_t _rtld_tlsdesc_handle(struct tls_data *, u_int);
/*
* AARCH64 PLT looks like this;
@@ -79,6 +116,71 @@ _rtld_setup_pltgot(const Obj_Entry *obj)
obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
}
+static struct tls_data *
+_rtld_tlsdesc_alloc(Obj_Entry *obj, const Elf_Rela *rela)
+{
+ struct tls_data *tlsdesc;
+
+ tlsdesc = xmalloc(sizeof(*tlsdesc));
+ tlsdesc->index = -1;
+ tlsdesc->obj = obj;
+ tlsdesc->rela = rela;
+
+ return tlsdesc;
+}
+
+static int64_t
+_rtld_tlsdesc_handle_locked(struct tls_data *tlsdesc, u_int flags)
+{
+ const Elf_Rela *rela;
+ const Elf_Sym *def;
+ const Obj_Entry *defobj;
+ Obj_Entry *obj;
+
+ rela = tlsdesc->rela;
+ obj = tlsdesc->obj;
+
+ def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, flags);
+ if (def == NULL)
+ _rtld_die();
+
+ tlsdesc->index = defobj->tlsoffset + def->st_value + rela->r_addend +
+ sizeof(struct tls_tcb);
+
+ return tlsdesc->index;
+}
+
+int64_t
+_rtld_tlsdesc_handle(struct tls_data *tlsdesc, u_int flags)
+{
+ sigset_t mask;
+
+ /* We have already found the index, return it */
+ if (tlsdesc->index >= 0)
+ return tlsdesc->index;
+
+ _rtld_exclusive_enter(&mask);
+ /* tlsdesc->index may have been set by another thread */
+ if (tlsdesc->index == -1)
+ _rtld_tlsdesc_handle_locked(tlsdesc, flags);
+ _rtld_exclusive_exit(&mask);
+
+ return tlsdesc->index;
+}
+
+static void
+_rtld_tlsdesc_fill(Obj_Entry *obj, const Elf_Rela *rela, Elf_Addr *where)
+{
+ if (ELF_R_SYM(rela->r_info) == 0) {
+ where[0] = (Elf_Addr)_rtld_tlsdesc;
+ where[1] = obj->tlsoffset + rela->r_addend +
+ sizeof(struct tls_tcb);
+ } else {
+ where[0] = (Elf_Addr)_rtld_tlsdesc_dynamic;
+ where[1] = (Elf_Addr)_rtld_tlsdesc_alloc(obj, rela);
+ }
+}
+
void
_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
{
@@ -173,6 +275,10 @@ _rtld_relocate_nonplt_objects(Obj_Entry
rdbg(("COPY (avoid in main)"));
break;
+ case R_TYPE(TLSDESC):
+ _rtld_tlsdesc_fill(obj, rela, where);
+ break;
+
case R_TLS_TYPE(TLS_DTPREL):
*where = (Elf_Addr)(def->st_value + rela->r_addend);
@@ -239,11 +345,7 @@ _rtld_relocate_plt_lazy(Obj_Entry *obj)
rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
break;
case R_TYPE(TLSDESC):
- assert(ELF_R_SYM(rela->r_info) == 0); /* XXX */
- if (ELF_R_SYM(rela->r_info) == 0) {
- where[0] = (Elf_Addr)_rtld_tlsdesc;
- where[1] = obj->tlsoffset + rela->r_addend + sizeof(struct tls_tcb);
- }
+ _rtld_tlsdesc_fill(obj, rela, where);
break;
}
}
@@ -280,29 +382,40 @@ _rtld_relocate_plt_object(const Obj_Entr
Elf_Addr new_value;
const Elf_Sym *def;
const Obj_Entry *defobj;
- unsigned long info = rela->r_info;
-
- assert(ELF_R_TYPE(info) == R_TYPE(JUMP_SLOT));
- def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL);
- if (__predict_false(def == NULL))
- return -1;
- if (__predict_false(def == &_rtld_sym_zero))
- return 0;
-
- if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
- if (tp == NULL)
+ switch (ELF_R_TYPE(rela->r_info)) {
+ case R_TYPE(JUMP_SLOT):
+ def = _rtld_find_plt_symdef(ELF_R_SYM(rela->r_info), obj,
+ &defobj, tp != NULL);
+ if (__predict_false(def == NULL))
+ return -1;
+ if (__predict_false(def == &_rtld_sym_zero))
return 0;
- new_value = _rtld_resolve_ifunc(defobj, def);
- } else {
- new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
+
+ if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
+ if (tp == NULL)
+ return 0;
+ new_value = _rtld_resolve_ifunc(defobj, def);
+ } else {
+ new_value = (Elf_Addr)(defobj->relocbase +
+ def->st_value);
+ }
+ rdbg(("bind now/fixup in %s --> old=%p new=%p",
+ defobj->strtab + def->st_name, (void *)*where,
+ (void *)new_value));
+ if (*where != new_value)
+ *where = new_value;
+ if (tp)
+ *tp = new_value;
+ break;
+ case R_TYPE(TLSDESC):
+ if (ELF_R_SYM(rela->r_info) != 0) {
+ struct tls_data *tlsdesc = (struct tls_data *)where[1];
+ if (tlsdesc->index == -1)
+ _rtld_tlsdesc_handle(tlsdesc, SYMLOOK_IN_PLT);
+ }
+ break;
}
- rdbg(("bind now/fixup in %s --> old=%p new=%p",
- defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
- if (*where != new_value)
- *where = new_value;
- if (tp)
- *tp = new_value;
return 0;
}
Index: src/libexec/ld.elf_so/arch/aarch64/rtld_start.S
diff -u src/libexec/ld.elf_so/arch/aarch64/rtld_start.S:1.2 src/libexec/ld.elf_so/arch/aarch64/rtld_start.S:1.3
--- src/libexec/ld.elf_so/arch/aarch64/rtld_start.S:1.2 Sun Feb 4 21:49:51 2018
+++ src/libexec/ld.elf_so/arch/aarch64/rtld_start.S Thu Sep 20 18:41:05 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: rtld_start.S,v 1.2 2018/02/04 21:49:51 skrll Exp $ */
+/* $NetBSD: rtld_start.S,v 1.3 2018/09/20 18:41:05 jakllsch Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -29,9 +29,38 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
+/*-
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Andrew Turner under
+ * sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
#include <machine/asm.h>
-RCSID("$NetBSD: rtld_start.S,v 1.2 2018/02/04 21:49:51 skrll Exp $")
+RCSID("$NetBSD: rtld_start.S,v 1.3 2018/09/20 18:41:05 jakllsch Exp $")
/*
* void _rtld_start(void (*cleanup)(void), const Obj_Entry *obj,
@@ -121,3 +150,42 @@ ENTRY(_rtld_tlsdesc)
ldr x0, [x0, #8]
ret
END(_rtld_tlsdesc)
+
+/*
+ * uint64_t _rtld_tlsdesc_dynamic(struct tlsdesc *);
+ *
+ * TODO: We could lookup the saved index here to skip saving the entire stack.
+ */
+ENTRY(_rtld_tlsdesc_dynamic)
+ /* Store any registers we may use in rtld_tlsdesc_handle */
+ stp x29, x30, [sp, #-(10 * 16)]!
+ mov x29, sp
+ stp x1, x2, [sp, #(1 * 16)]
+ stp x3, x4, [sp, #(2 * 16)]
+ stp x5, x6, [sp, #(3 * 16)]
+ stp x7, x8, [sp, #(4 * 16)]
+ stp x9, x10, [sp, #(5 * 16)]
+ stp x11, x12, [sp, #(6 * 16)]
+ stp x13, x14, [sp, #(7 * 16)]
+ stp x15, x16, [sp, #(8 * 16)]
+ stp x17, x18, [sp, #(9 * 16)]
+
+ /* Find the tls offset */
+ ldr x0, [x0, #8]
+ mov x1, #1
+ bl _rtld_tlsdesc_handle
+
+ /* Restore the registers */
+ ldp x17, x18, [sp, #(9 * 16)]
+ ldp x15, x16, [sp, #(8 * 16)]
+ ldp x13, x14, [sp, #(7 * 16)]
+ ldp x11, x12, [sp, #(6 * 16)]
+ ldp x9, x10, [sp, #(5 * 16)]
+ ldp x7, x8, [sp, #(4 * 16)]
+ ldp x5, x6, [sp, #(3 * 16)]
+ ldp x3, x4, [sp, #(2 * 16)]
+ ldp x1, x2, [sp, #(1 * 16)]
+ ldp x29, x30, [sp], #(10 * 16)
+
+ ret
+END(_rtld_tlsdesc_dynamic)
