164 lines
6.4 KiB
Diff
164 lines
6.4 KiB
Diff
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commit 50a2d83c08a94a10f88a1fedeb7a6e3667a6b732
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Author: Florian Weimer <fweimer@redhat.com>
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Date: Fri Apr 24 22:13:03 2020 +0200
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elf: Introduce <elf_machine_sym_no_match.h>
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MIPS needs to ignore certain existing symbols during symbol lookup.
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The old scheme uses the ELF_MACHINE_SYM_NO_MATCH macro, with an
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inline function, within its own header, with a sysdeps override for
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MIPS. This allows re-use of the function from another file (without
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having to include <dl-machine.h> or providing the default definition
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for ELF_MACHINE_SYM_NO_MATCH).
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Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c
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index e4c479de9a1fd6ec..47acd134600b44b5 100644
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--- a/elf/dl-lookup.c
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+++ b/elf/dl-lookup.c
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@@ -28,18 +28,12 @@
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#include <libc-lock.h>
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#include <tls.h>
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#include <atomic.h>
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+#include <elf_machine_sym_no_match.h>
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#include <assert.h>
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-/* Return nonzero if check_match should consider SYM to fail to match a
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- symbol reference for some machine-specific reason. */
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-#ifndef ELF_MACHINE_SYM_NO_MATCH
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-# define ELF_MACHINE_SYM_NO_MATCH(sym) 0
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-#endif
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-
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#define VERSTAG(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (tag))
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-
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struct sym_val
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{
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const ElfW(Sym) *s;
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@@ -78,7 +72,7 @@ check_match (const char *const undef_name,
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if (__glibc_unlikely ((sym->st_value == 0 /* No value. */
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&& sym->st_shndx != SHN_ABS
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&& stt != STT_TLS)
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- || ELF_MACHINE_SYM_NO_MATCH (sym)
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+ || elf_machine_sym_no_match (sym)
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|| (type_class & (sym->st_shndx == SHN_UNDEF))))
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return NULL;
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diff --git a/sysdeps/generic/elf_machine_sym_no_match.h b/sysdeps/generic/elf_machine_sym_no_match.h
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new file mode 100644
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index 0000000000000000..27155de4c0358460
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--- /dev/null
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+++ b/sysdeps/generic/elf_machine_sym_no_match.h
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@@ -0,0 +1,34 @@
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+/* Function to ignore certain symbol matches for machine-specific reasons.
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+ Copyright (C) 2020 Free Software Foundation, Inc.
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+ This file is part of the GNU C Library.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _ELF_MACHINE_SYM_NO_MATCH_H
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+#define _ELF_MACHINE_SYM_NO_MATCH_H
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+
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+#include <link.h>
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+#include <stdbool.h>
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+
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+/* This can be customized to ignore certain symbols during lookup in
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+ case there are machine-specific rules to disregard some
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+ symbols. */
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+static inline bool
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+elf_machine_sym_no_match (const ElfW(Sym) *sym)
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+{
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+ return false;
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+}
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+
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+#endif /* _ELF_MACHINE_SYM_NO_MATCH_H */
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diff --git a/sysdeps/mips/dl-machine.h b/sysdeps/mips/dl-machine.h
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index 91fc640388a735c7..b41e10647d81843b 100644
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--- a/sysdeps/mips/dl-machine.h
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+++ b/sysdeps/mips/dl-machine.h
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@@ -467,21 +467,6 @@ elf_machine_plt_value (struct link_map *map, const ElfW(Rel) *reloc,
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return value;
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}
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-/* The semantics of zero/non-zero values of undefined symbols differs
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- depending on whether the non-PIC ABI is in use. Under the non-PIC
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- ABI, a non-zero value indicates that there is an address reference
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- to the symbol and thus it must always be resolved (except when
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- resolving a jump slot relocation) to the PLT entry whose address is
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- provided as the symbol's value; a zero value indicates that this
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- canonical-address behaviour is not required. Yet under the classic
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- MIPS psABI, a zero value indicates that there is an address
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- reference to the function and the dynamic linker must resolve the
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- symbol immediately upon loading. To avoid conflict, symbols for
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- which the dynamic linker must assume the non-PIC ABI semantics are
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- marked with the STO_MIPS_PLT flag. */
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-#define ELF_MACHINE_SYM_NO_MATCH(sym) \
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- ((sym)->st_shndx == SHN_UNDEF && !((sym)->st_other & STO_MIPS_PLT))
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-
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#endif /* !dl_machine_h */
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#ifdef RESOLVE_MAP
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diff --git a/sysdeps/mips/elf_machine_sym_no_match.h b/sysdeps/mips/elf_machine_sym_no_match.h
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new file mode 100644
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index 0000000000000000..9d09e5fa2db1ff6c
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--- /dev/null
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+++ b/sysdeps/mips/elf_machine_sym_no_match.h
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@@ -0,0 +1,43 @@
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+/* MIPS-specific handling of undefined symbols.
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+ Copyright (C) 2008-2020 Free Software Foundation, Inc.
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+ This file is part of the GNU C Library.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _ELF_MACHINE_SYM_NO_MATCH_H
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+#define _ELF_MACHINE_SYM_NO_MATCH_H
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+
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+#include <link.h>
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+#include <stdbool.h>
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+
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+/* The semantics of zero/non-zero values of undefined symbols differs
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+ depending on whether the non-PIC ABI is in use. Under the non-PIC
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+ ABI, a non-zero value indicates that there is an address reference
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+ to the symbol and thus it must always be resolved (except when
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+ resolving a jump slot relocation) to the PLT entry whose address is
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+ provided as the symbol's value; a zero value indicates that this
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+ canonical-address behaviour is not required. Yet under the classic
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+ MIPS psABI, a zero value indicates that there is an address
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+ reference to the function and the dynamic linker must resolve the
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+ symbol immediately upon loading. To avoid conflict, symbols for
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+ which the dynamic linker must assume the non-PIC ABI semantics are
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+ marked with the STO_MIPS_PLT flag. */
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+static inline bool
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+elf_machine_sym_no_match (const ElfW(Sym) *sym)
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+{
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+ return sym->st_shndx == SHN_UNDEF && !(sym->st_other & STO_MIPS_PLT);
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+}
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+
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+#endif /* _ELF_MACHINE_SYM_NO_MATCH_H */
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