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* Update copyright dates with scripts/update-copyrightsPaul Eggert2021-01-021-1/+1
| | | | | | | | | | | | | | | | I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
* aarch64: Use mmap to add PROT_BTI instead of mprotect [BZ #26831]Szabolcs Nagy2020-12-111-1/+7
| | | | | | | | | | | | | | | | | | | | | Re-mmap executable segments if possible instead of using mprotect to add PROT_BTI. This allows using BTI protection with security policies that prevent mprotect with PROT_EXEC. If the fd of the ELF module is not available because it was kernel mapped then mprotect is used and failures are ignored. To protect the main executable even when mprotect is filtered the linux kernel will have to be changed to add PROT_BTI to it. The delayed failure reporting is mainly needed because currently _dl_process_gnu_properties does not propagate failures such that the required cleanups happen. Using the link_map_machine struct for error propagation is not ideal, but this seemed to be the least intrusive solution. Fixes bug 26831. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Pass the fd to note processingSzabolcs Nagy2020-12-111-3/+3
| | | | | | | | | | | | | | To handle GNU property notes on aarch64 some segments need to be mmaped again, so the fd of the loaded ELF module is needed. When the fd is not available (kernel loaded modules), then -1 is passed. The fd is passed to both _dl_process_pt_gnu_property and _dl_process_pt_note for consistency. Target specific note processing functions are updated accordingly. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* aarch64: enable BTI at runtimeSudakshina Das2020-07-081-0/+63
Binaries can opt-in to using BTI via an ELF object file marking. The dynamic linker has to then mprotect the executable segments with PROT_BTI. In case of static linked executables or in case of the dynamic linker itself, PROT_BTI protection is done by the operating system. On AArch64 glibc uses PT_GNU_PROPERTY instead of PT_NOTE to check the properties of a binary because PT_NOTE can be unreliable with old linkers (old linkers just append the notes of input objects together and add them to the output without checking them for consistency which means multiple incompatible GNU property notes can be present in PT_NOTE). BTI property is handled in the loader even if glibc is not built with BTI support, so in theory user code can be BTI protected independently of glibc. In practice though user binaries are not marked with the BTI property if glibc has no support because the static linked libc objects (crt files, libc_nonshared.a) are unmarked. This patch relies on Linux userspace API that is not yet in a linux release but in v5.8-rc1 so scheduled to be in Linux 5.8. Co-authored-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>