elf: Issue la_symbind for bind-now (BZ #23734)

The audit symbind callback is not called for binaries built with
-Wl,-z,now or when LD_BIND_NOW=1 is used, nor the PLT tracking callbacks
(plt_enter and plt_exit) since this would change the expected
program semantics (where no PLT is expected) and would have performance
implications (such as for BZ#15533).

LAV_CURRENT is also bumped to indicate the audit ABI change (where
la_symbind flags are set by the loader to indicate no possible PLT
trace).

To handle powerpc64 ELFv1 function descriptor, _dl_audit_symbind
requires to know whether bind-now is used so the symbol value is
updated to function text segment instead of the OPD (for lazy binding
this is done by PPC64_LOAD_FUNCPTR on _dl_runtime_resolve).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
powerpc64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

5 files changed, 52 insertions, 1 deletions

diff --git a/sysdeps/generic/dl-lookupcfg.h b/sysdeps/generic/dl-lookupcfg.h
index 7460c0596a..95bcfc1cc1 100644
--- a/sysdeps/generic/dl-lookupcfg.h
+++ b/sysdeps/generic/dl-lookupcfg.h
@@ -26,3 +26,6 @@
 #define DL_FIXUP_VALUE_CODE_ADDR(value) (value)
 #define DL_FIXUP_VALUE_ADDR(value) (value)
 #define DL_FIXUP_ADDR_VALUE(addr) (addr)
+#define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr)
+#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \
+  (*value) = st_value;
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 97061bdf9f..2ebe7901c0 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1431,7 +1431,10 @@ void _dl_audit_objclose (struct link_map *l)
 /* Call the la_preinit from the audit modules for the link_map L.  */
 void _dl_audit_preinit (struct link_map *l);
 
-/* Call the la_symbind{32,64} from the audit modules for the link_map L.  */
+/* Call the la_symbind{32,64} from the audit modules for the link_map L.  If
+   RELOC_RESULT is NULL it assumes the symbol to be bind-now and will set
+   the flags with LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT prior calling
+   la_symbind{32,64}.  */
 void _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,
 			const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,
 			lookup_t result)
diff --git a/sysdeps/hppa/dl-lookupcfg.h b/sysdeps/hppa/dl-lookupcfg.h
index 5d381147c0..8da2412fea 100644
--- a/sysdeps/hppa/dl-lookupcfg.h
+++ b/sysdeps/hppa/dl-lookupcfg.h
@@ -80,3 +80,6 @@ void attribute_hidden _dl_unmap (struct link_map *map);
 #define DL_FIXUP_VALUE_CODE_ADDR(value) ((value).ip)
 #define DL_FIXUP_VALUE_ADDR(value) ((uintptr_t) &(value))
 #define DL_FIXUP_ADDR_VALUE(addr) (*(struct fdesc *) (addr))
+#define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr)
+#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \
+  (*value) = *(struct fdesc *) (st_value)
diff --git a/sysdeps/ia64/dl-lookupcfg.h b/sysdeps/ia64/dl-lookupcfg.h
index b8ab1bba15..3df3116b31 100644
--- a/sysdeps/ia64/dl-lookupcfg.h
+++ b/sysdeps/ia64/dl-lookupcfg.h
@@ -74,3 +74,6 @@ extern void attribute_hidden _dl_unmap (struct link_map *map);
 
 #define DL_FIXUP_VALUE_ADDR(value) ((uintptr_t) &(value))
 #define DL_FIXUP_ADDR_VALUE(addr) (*(struct fdesc *) (addr))
+#define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr)
+#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \
+  (*value) = *(struct fdesc *) (st_value)
diff --git a/sysdeps/powerpc/dl-lookupcfg.h b/sysdeps/powerpc/dl-lookupcfg.h
new file mode 100644
index 0000000000..25abcc1d12
--- /dev/null
+++ b/sysdeps/powerpc/dl-lookupcfg.h
@@ -0,0 +1,39 @@
+/* Configuration of lookup functions.  PowerPC version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define DL_FIXUP_VALUE_TYPE ElfW(Addr)
+#define DL_FIXUP_MAKE_VALUE(map, addr) (addr)
+#define DL_FIXUP_VALUE_CODE_ADDR(value) (value)
+#define DL_FIXUP_VALUE_ADDR(value) (value)
+#define DL_FIXUP_ADDR_VALUE(addr) (addr)
+#if __WORDSIZE == 64 && _CALL_ELF == 1
+/* We need to correctly set the audit modules value for bind-now.  */
+# define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) \
+ (((Elf64_FuncDesc *)(addr))->fd_func)
+# define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value)	\
+ ({								\
+    Elf64_FuncDesc *opd = (Elf64_FuncDesc *) (value);		\
+    opd->fd_func = (st_value);					\
+    if ((new_value) != (uintptr_t) (st_value))			\
+     opd->fd_toc = ((Elf64_FuncDesc *)(new_value))->fd_toc;	\
+  })
+#else
+# define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr)
+# define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value)	\
+  (*value) = st_value;
+#endif