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| author | Fangrui Song <maskray@google.com> | 2021-10-07 11:55:02 -0700 |
|---|---|---|
| committer | Fangrui Song <maskray@google.com> | 2021-10-07 11:55:02 -0700 |
| commit | 490e6c62aa31a8aa5c4a059f6e646ede121edf0a (patch) | |
| tree | 40bedb62d8b555792f91c82127b0f599da90ef39 /elf/get-dynamic-info.h | |
| parent | 349b0441dab375099b1d7f6909c1742286a67da9 (diff) | |
| download | glibc-490e6c62aa31a8aa5c4a059f6e646ede121edf0a.tar.gz glibc-490e6c62aa31a8aa5c4a059f6e646ede121edf0a.tar.xz glibc-490e6c62aa31a8aa5c4a059f6e646ede121edf0a.zip | |
elf: Avoid nested functions in the loader [BZ #27220]
dynamic-link.h is included more than once in some elf/ files (rtld.c,
dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested
functions. This harms readability and the nested functions usage
is the biggest obstacle prevents Clang build (Clang doesn't support GCC
nested functions).
The key idea for unnesting is to add extra parameters (struct link_map
*and struct r_scope_elm *[]) to RESOLVE_MAP,
ELF_MACHINE_BEFORE_RTLD_RELOC, ELF_DYNAMIC_RELOCATE, elf_machine_rel[a],
elf_machine_lazy_rel, and elf_machine_runtime_setup. (This is inspired
by Stan Shebs' ppc64/x86-64 implementation in the
google/grte/v5-2.27/master which uses mixed extra parameters and static
variables.)
Future simplification:
* If mips elf_machine_runtime_setup no longer needs RESOLVE_GOTSYM,
elf_machine_runtime_setup can drop the `scope` parameter.
* If TLSDESC no longer need to be in elf_machine_lazy_rel,
elf_machine_lazy_rel can drop the `scope` parameter.
Tested on aarch64, i386, x86-64, powerpc64le, powerpc64, powerpc32,
sparc64, sparcv9, s390x, s390, hppa, ia64, armhf, alpha, and mips64.
In addition, tested build-many-glibcs.py with {arc,csky,microblaze,nios2}-linux-gnu
and riscv64-linux-gnu-rv64imafdc-lp64d.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'elf/get-dynamic-info.h')
| -rw-r--r-- | elf/get-dynamic-info.h | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 4aa2058abf..15c316b38c 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -16,18 +16,15 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -/* This file is included multiple times and therefore lacks a header - file inclusion guard. */ +/* Populate dynamic tags in l_info. */ + +#ifndef _GET_DYNAMIC_INFO_H +#define _GET_DYNAMIC_INFO_H #include <assert.h> #include <libc-diag.h> -#ifndef RESOLVE_MAP -static -#else -auto -#endif -inline void __attribute__ ((unused, always_inline)) +static inline void __attribute__ ((unused, always_inline)) elf_get_dynamic_info (struct link_map *l) { #if __ELF_NATIVE_CLASS == 32 @@ -165,3 +162,5 @@ elf_get_dynamic_info (struct link_map *l) info[DT_RPATH] = NULL; #endif } + +#endif |