If a signal arrived during a symbol lookup and the signal handler also
required a symbol lookup, the end of the lookup in the signal handler reset
the flag whether restoring AVX/SSE registers is needed. Resetting means
in this case that the tail part of the outer lookup code will try to
restore the registers and this can fail miserably. We now restore to the
previous value which makes nesting calls possible.
This patch fixes mixed SSE/AVX audit and checks AVX only once in
_dl_runtime_profile. When an AVX or SSE register value in pltenter is
modified, we have to make sure that the SSE part value is the same in both
lr_xmm and lr_vector fields so that pltexit will get the correct value
from either lr_xmm or lr_vector fields. AVX-enabled pltenter should
update both lr_xmm and lr_vector fields to support stacked AVX/SSE
pltenter functions.
SSE registers are used for passing parameters and must be preserved
in runtime relocations. This is inside ld.so enforced through the
tests in tst-xmmymm.sh. But the malloc routines used after startup
come from libc.so and can be arbitrarily complex. It's overkill
to save the SSE registers all the time because of that. These calls
are rare. Instead we save them on demand. The new infrastructure
put in place in this patch makes this possible and efficient.
The original AVX patch used a function pointer to handle the difference
between machines with and without AVX support. This is insecure. A
well-placed memory exploit could lead to redirection of the execution.
Using a variable and several tests is a bit slower but cannot be
exploited in this way.
* inet/inet6_rth.c (inet6_rth_add): Add some error checking.
Patch mostly by Yang Hongyang <yanghy@cn.fujitsu.com>.
* inet/Makefile (tests): Add tst-inet6_rth.
* inet/tst-inet6_rth.c: New file.
alignment of La_x86_64_regs. Store xmm parameters.
(reloc_index): Define.
(_dl_fixup): Rename reloc_offset parameter to reloc_arg.
(_dl_fixup_profile): Likewise. Use reloc_index instead of
computing index from reloc_offset.
(_dl_call_pltexit): Likewise.
* sysdeps/x86_64/dl-trampoline.S (_dl_runtime_resolve): Just pass
the relocation index to _dl_fixup.
(_dl_runtime_profile): Likewise for _dl_fixup_profile and
_dl_call_pltexit.
* sysdeps/x86_64/dl-runtime.c: New file.
* sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Fix
alignement of La_x86_64_regs. Store xmm parameters.
Patch mostly by Jiri Olsa <olsajiri@gmail.com>.
