rtld and libc use different storage, so the initial version would
incorrectly report the failure reason for fork().
There is still a small race condition inside ld.elf_so as it doesn't use
thread-safe errno internally, but that's a more contained internal
issue.
in a consistent state. This most importantly avoids races between dlopen
and friends and fork, potentially resulting in dead locks in the child
when it itself tries to acquire locks.
on a linker common page size boundary. However, if the common page size
used by the linker is less than the VM page size being used by the kernel,
this can end up in the middle of a VM page and when the region is write-
protected, this can cause objects in neighboring .data to get incorrectly
write-protected, resulting in a crash.
Avoid this situation by calculating the end of the RELRO region not by
rounding memsz up to the VM page size, but rather by adding vaddr + memsz
and then truncating to the VM page size.
Fixes PR toolchain/55043.
XXX pullup-9
DT_GNU_HASH serves the same purpose as DT_HASH, however it is a distinct
and faster apprach implemented and designed in the GNU toolchain in 2006.
DT_GNU_HASH is preferred whenever available.
Original GNU benchmarks claim 50% faster dynamic linking time.
https://www.sourceware.org/ml/binutils/2006-06/msg00418.html
Code based on FreeBSD and OpenBSD, both were based on DragonFlyBSD.
Define Elf_Hash struct that contains ELF/SYSV and GNU hash checksum.
Implement _rtld_gnu_hash() for DT_GNU_HASH.
Adapt existing code to compute all Elf_Hash types, instead of only
the ELF/SYSV one.
Rename _rtld_elf_hash() to _rtld_sysv_hash() to match the GNU toolchain
terminology.
_rtld_gnu_hash() uses Dan Bernstein's string hash function posted eons ago
on comp.lang.c.
The sanitizer does not work reliably before finishing initialization of
ld.elf_so. There is also a number of false positives that are not real
problems here.
GCC_NO_FORMAT_TRUNCATION -Wno-format-truncation (GCC 7/8)
GCC_NO_STRINGOP_TRUNCATION -Wno-stringop-truncation (GCC 8)
GCC_NO_STRINGOP_OVERFLOW -Wno-stringop-overflow (GCC 8)
GCC_NO_CAST_FUNCTION_TYPE -Wno-cast-function-type (GCC 8)
use these to turn off warnings for most GCC-8 complaints. many
of these are false positives, most of the real bugs are already
commited, or are yet to come.
we plan to introduce versions of (some?) of these that use the
"-Wno-error=" form, which still displays the warnings but does
not make it an error, and all of the above will be re-considered
as either being "fix me" (warning still displayed) or "warning
is wrong."
auth_level and require_secure_login were defined in two places:
- global.c that picked it from headers and removed 'extern'
- telnetd.c that initialized it to 0
line was defined twice: in global.c and sys_term.c with a non-zero value.
Remove the definition and initialization from sys_term.c and initialize
the variable early in main().
Detected during the build of telned with Address Sanitizer (MKSANITIZER).
Reviewed by <mrg>
on arm after switching to new jemalloc.
jemalloc invokes __tls_get_addr() under some condition. If anything other
than ld.elf_so nor libc exports it, inconsistency arises as a result.
joerg