support for indirect functions was added. This fixes {init,fini}_array support
on hppa where each member of the array is (already) a plabel.
Discussed with joerg.
4 files changed, 29 insertions(+), 39 deletions(-)
: ----------------------------------------------------------------------
The use of membar_enter is to separate atomic r/m/w on a lock from
the body of the critical section so two different critical sections
happen in order:
body of previous critical section;
exit critical section:
membar_exit();
atomic_r/m/w(lock stuff);
enter critical section:
atomic_r/m/w(lock stuff);
membar_enter();
body of next critical section;
_rtld_shared_enter does this, but it _also_ issued an extraneous
membar_enter before the atomic_r/m/w part, which doesn't impose any
semantically important order but may cost some performance.
Changes:
- Add a new field r_ldbase in the r_debug struct.
- Set r_version to 1.
This harmonizes the support with OpenBSD and Linux.
FreeBSD uses version 0 (or no version).
Solaris uses version 2 that is not implemented elsewhere and relies on
SVR4 specific design and interfaces.
Update the code comments as r_debug and link_map is used by other software
than GDB, namely: sanitizers, rump, LLDB.
treat them like R_PPC_ADDR32
XXX
these relocs have been observed in the xf86-video-radeon driver, but only in
the AtomBios support code, which is unused on PowerPC. This allows the driver
to load but it's not clear if the affected parts would actually function.
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.
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.
NetBSD.
This brings us resolving for dynamically loaded libraries and makes
tests/libexec/ld.elf_so/t_thread_local_dtor pass.
With suggestions from joerg@
skrll