Fixes to address issues from BZ #15022 resolution, as follows:
* TLS updates to csu/libc-tls.c -- we now have a proper main map, so
there's no longer a need to create a separate fake one to keep TLS
structures,
* random updates to elf/dl-close.c -- LM_ID_BASE is now a valid name
space ID for static executables as well, so assert that we don't
unload the main map. Similarly dl_nns isn't supposed to be 0 for
static executables anymore,
* actual BZ #16046 fix to elf/dl-iteratephdr.c -- the dl_iterate_phdr
special function for static executables isn't needed anymore, provided
that l_phdr and l_phnum members of the main map have been properly
initialized (done in _dl_non_dynamic_init in elf/dl-support.c now),
* ld.so.cache loader update to elf/dl-load.c --
GL(dl_ns)[LM_ID_BASE]._ns_loaded is now always initialized in static
executables so can become the fallback loader map to check for
DF_1_NODEFLIB, provided that the l_flags_1 member of the main map has
been properly initialized (done in elf/dl-support.c now); this also
ensures previous semantics elsewhere in elf/dl-load.c,
* matching updates to elf/dl-support.c -- to complement the two fixes
above.
The pointer guard used for pointer mangling was not initialized for
static applications resulting in the security feature being disabled.
The pointer guard is now correctly initialized to a random value for
static applications. Existing static applications need to be
recompiled to take advantage of the fix.
The test tst-ptrguard1-static and tst-ptrguard1 add regression
coverage to ensure the pointer guards are sufficiently random
and initialized to a default value.
Long ago static startup did not parse the auxiliary vector and therefore
could not get at any `AT_FPUCW' tag to check whether upon FPU context
allocation the kernel would use a FPU control word setting different to
that provided by the `__fpu_control' variable. Static startup therefore
always initialized the FPU control word, forcing immediate FPU context
allocation even for binaries that otherwise never used the FPU.
As from GIT commit f8f900ecb9 static
startup supports parsing the auxiliary vector, so now it can avoid
explicit initialization of the FPU control word, just as can dynamic
startup, in the usual case where the setting written to the FPU control
word would be the same as the kernel uses. This defers FPU context
allocation until the binary itself actually pokes at the FPU.
Note that the `AT_FPUCW' tag is usually absent from the auxiliary vector
in which case _FPU_DEFAULT is assumed to be the kernel default.
This reverts the change that allows the POSIX Thread default stack size
to be changed by the environment variable
GLIBC_PTHREAD_DEFAULT_STACKSIZE. It has been requested that more
discussion happen before this change goes into 2.18.
* csu/libc-tls.c (static_dtv): Renamed to ...
(_dl_static_dtv): This. Make it global.
(_dl_initial_dtv): Removed.
(__libc_setup_tls): Updated.
* elf/dl-tls.c (DL_INITIAL_DTV): New macro.
(_dl_deallocate_tls): Replace GL(dl_initial_dtv) with
DL_INITIAL_DTV.
GCC 4.5 warns about "extern void _end; &end;".
Use char[] instead, as that also doesn't fall foul
of a target's .sdata optimizations.
Signed-off-by: Richard Henderson <rth@twiddle.net>
