[PATCH v3 0/5] fix ifunc with static pie [BZ #27072]
Szabolcs Nagy
szabolcs.nagy@arm.com
Tue Jan 12 17:21:25 GMT 2021
v3:
- refactor tunables: move internals out of dl-tunables.h
- use generated max string length in the tunables list
instead of magic values.
v2:
- check PI_STATIC_AND_HIDDEN for --enable-static-pie
- change string buffer sizes in the tunables
- fix env_alias == NULL logic in __tunables_init
- move __ehdr_start processing after self relocation
force pushed into nsz/bug27072 branch (with a gcc8 bug
workaround for aarch64)
Issues that are not addressed:
- tunables try to allocate memory even with non-suid exe.
allocation is only needed for rewriting the GLIBC_TUNABLES
env var. i think a case can be made that if anything there
is TUNABLE_SECLEVEL_SXID_ERASE then this env var would be
simply dropped.
- tunable list is not optimized for compactness.
- all symbols are forced hidden in libc.a, but i think lib*.a
should do the same. (other than lib*_nonshared.a)
Szabolcs Nagy (5):
configure: Require PI_STATIC_AND_HIDDEN for static pie
Make libc symbols hidden in static PIE
elf: Make the tunable struct definition internal only
elf: Avoid RELATIVE relocs in __tunables_init
csu: Move static pie self relocation later [BZ #27072]
configure | 14 +++++++++++++
configure.ac | 5 +++++
csu/libc-start.c | 44 +++++++++++++++++++++++-----------------
elf/dl-tunable-types.h | 42 +++++++++++++++++++++++++++++---------
elf/dl-tunables.c | 2 +-
elf/dl-tunables.h | 35 ++++++++------------------------
include/libc-symbols.h | 8 ++++++--
scripts/gen-tunables.awk | 16 +++++++++++++--
8 files changed, 105 insertions(+), 61 deletions(-)
--
2.17.1
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