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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2022-01-24 10:46:17 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2022-02-01 14:49:46 -0300
commit32612615c58b394c3eb09f020f31310797ad3854 (patch)
tree3e6b65aaabd471f79a2179e75bbf64ccd1a6fa04 /sysdeps/powerpc
parent254d3d5aef2fd8430c469e1938209ac100ebf132 (diff)
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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>
Diffstat (limited to 'sysdeps/powerpc')
-rw-r--r--sysdeps/powerpc/dl-lookupcfg.h39
1 files changed, 39 insertions, 0 deletions
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