Previously, Bionic's dl_phdr_info only included the first four
dl_iterate_phdr fields. Several other libc's have these additional fields:
unsigned long long dlpi_adds -- incremented when a library is loaded
unsigned long long dlpi_subs -- incremented when a library is unloaded
size_t dlpi_tls_modid -- TLS module ID
void* dlpi_tls_data -- pointer to current thread's TLS block or NULL
These extra fields are also exposed by glibc, musl, and FreeBSD. The
unwinder in libgcc.a, linked into shipping Android DSOs, has a
PC->eh_frame cache that activates if dl_phdr_info has the dlpi_adds and
dlpi_subs fields (indicated at run-time by a sufficiently-large size
argument to the callback).
Bug: https://github.com/android-ndk/ndk/issues/1062
Test: bionic unit tests
Change-Id: I6f0bab548cf8c828af2ddab9eb01c5c6d70cd81f
* LP32 should use sa_restorer too. gdb expects this, and future (>= 3.15) x86
kernels will apparently stop supporting the case where SA_RESTORER isn't
set.
* gdb and libunwind care about the exact instruction sequences, so we need to
modify the code slightly in a few cases to match what they're looking for.
* gdb also cares about the exact function names (for some architectures),
so we need to use __restore and __restore_rt rather than __sigreturn and
__rt_sigreturn.
* It's possible that we don't have a VDSO; dl_iterate_phdr shouldn't assume
that getauxval(AT_SYSINFO_EHDR) will return a non-null pointer.
This fixes unwinding through a signal handler in gdb for all architectures.
It doesn't fix libunwind for arm and arm64. I'll keep investigating that...
Bug: 17436734
Change-Id: Ic1ea1184db6655c5d96180dc07bcc09628e647cb
Remove the linker's reliance on BSD cruft and use the glibc-style
ElfW macro. (Other code too, but the linker contains the majority
of the code that needs to work for Elf32 and Elf64.)
All platforms need dl_iterate_phdr_static, so it doesn't make sense
to have that part of the per-architecture configuration.
Bug: 12476126
Change-Id: I1d7f918f1303a392794a6cd8b3512ff56bd6e487
