Linux CET kernel places a restore token on shadow stack for signal
handler to enhance security. The restore token is 8 byte and aligned
to 8 bytes. It is usually transparent to user programs since kernel
will pop the restore token when signal handler returns. But when an
exception is thrown from a signal handler, now we need to pop the
restore token from shadow stack. For x86-64, we just need to treat
the signal frame as normal frame. For i386, we need to search for
the restore token to check if the original shadow stack is 8 byte
aligned. If the original shadow stack is 8 byte aligned, we just
need to pop 2 slots, one restore token, from shadow stack. Otherwise,
we need to pop 3 slots, one restore token + 4 byte padding, from
shadow stack.
This patch also includes 2 tests, one has a restore token with 4 byte
padding and one without.
Tested on Linux/x86-64 CET machine with and without -m32.
libgcc/
PR libgcc/85334
* config/i386/shadow-stack-unwind.h (_Unwind_Frames_Increment):
New.
gcc/testsuite/
PR libgcc/85334
* g++.target/i386/pr85334-1.C: New test.
* g++.target/i386/pr85334-2.C: Likewise.
Commit r10-6500-g811a475ea3fcc55ee4aea7c81171891ef19dfc25 broke the
GCC build for arm-none-uclinuxfdpiceabi, as it forgot to update some
uses of gnu_Unwind_Find_got.
2020-02-10 Christophe Lyon <christophe.lyon@linaro.org>
libgcc/
PR target/93615
* unwind-arm-common.inc: Replace uses of gnu_Unwind_Find_got with
_Unwind_gnu_Find_got.
* unwind-pe.h: Likewise.
As the following testcase shows, unwind.h on ARM can't be (starting with GCC
10) compiled with -std=c* modes, only -std=gnu* modes.
The problem is it uses asm keyword, which isn't a keyword in those modes
(system headers vs. non-system ones don't make a difference here).
glibc and other installed headers use __asm or __asm__ keywords instead that
work fine in both standard and gnu modes.
While there, as it is an installed header, I think it is also wrong to
completely ignore any identifier namespace rules.
The generic unwind.h defines just _Unwind* namespace identifiers plus
_sleb128_t/_uleb128_t (but e.g. unlike libstdc++/glibc headers doesn't
uglify operand names), the ARM unwind.h is much worse here. I've just
changed the gnu_Unwind_Find_got function at least not be in user identifier
namespace, but perhaps it would be good to go further and rename e.g.
or e.g.
typedef _Unwind_Reason_Code (*personality_routine) (_Unwind_State,
_Unwind_Control_Block *, _Unwind_Context *);
in unwind-arm-common.h.
2020-02-07 Jakub Jelinek <jakub@redhat.com>
PR target/93615
* config/arm/unwind-arm.h (gnu_Unwind_Find_got): Rename to ...
(_Unwind_gnu_Find_got): ... this. Use __asm instead of asm. Remove
trailing :s in asm. Formatting fixes.
(_Unwind_decode_typeinfo_ptr): Adjust caller.
* gcc.dg/pr93615.c: New test.
On nios2-linux-gnu, there has been a long-standing bug in C++ exception
handling that sometimes resulted in link errors like
../nios2-linux-gnu/bin/ld: FDE encoding in /tmp/cccfpQ2l.o(.eh_frame) prevents .eh_frame_hdr table being created
when building some shared libraries or PIE executables. The root of
the problem is that GCC was incorrectly emitting an absolute encoding
in EH tables for PIC. This patch changes it to use either
DW_EH_PE_indirect (for global) or DW_EH_PE_datarel (for local), and
fixes libgcc so it can find the address of the GOT as the base address
for DW_EH_PE_datarel.
Complicating matters somewhat, GAS was missing support for
%gotoff(symbol) relocation syntax. I have just pushed a fix for that,
but I've added a configure check to test for presence of the binutils
support and fall back to the current absolute encoding (which works
most of the time) if it is not available. Once the fix makes it into
an official binutils release it might be appropriate to make this
error out instead.
Since this is a wrong-code bug and affects only nios2 target, I think
this is appropriate for Stage 4. I regression-tested on both
nios2-linux-gnu and nios2-elf, with and without the binutils support
present, before committing this.
2020-01-31 Sandra Loosemore <sandra@codesourcery.com>
gcc/
* configure.ac [nios2-*-*]: Check HAVE_AS_NIOS2_GOTOFF_RELOCATION.
* config.in: Regenerated.
* configure: Regenerated.
* config/nios2/nios2.h (ASM_PREFERRED_EH_DATA_FORMAT): Fix handling
for PIC when HAVE_AS_NIOS2_GOTOFF_RELOCATION.
(ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX): New.
gcc/testsuite/
* g++.target/nios2/hello-pie.C: New.
* g++.target/nios2/nios2.exp: New.
libgcc/
* config.host [nios2-*-linux*] (tmake_file, tm_file): Adjust.
* config/nios2-elf-lib.h: New.
* unwind-dw2-fde-dip.c (_Unwind_IteratePhdrCallback): Use existing
code for finding GOT base for nios2.
ARC processors can work with a reduced register set (i.e. registers
r4-r9 and r16-r25 are not available). This option can be enabled
passing -mrf16 option to the compiler, or by using -mcpu=em_mini CPU
configuration. Using RF16 config requires all the hand-made assembly
files used in libgcc to have the corresponding RF16 object attribute
set.
This patch qualifies the relevant hand-made assembly files to
RF16 config, and also adds generic c-functions for the one which are
not.
libgcc/
xxxx-xx-xx Claudiu Zissulescu <claziss@synopsys.com>
* config/arc/crti.S: Add RF16 object attribute.
* config/arc/crtn.S: Likewise.
* config/arc/crttls.S: Likewise.
* config/arc/lib1funcs.S: Likewise.
* config/arc/fp-hack.h (ARC_OPTFPE): Define.
* config/arc/lib2funcs.c: New file.
* config/arc/t-arc: Add lib2funcs to LIB2ADD.
libgcc/ChangeLog:
2020-01-23 Dragan Mladjenovic <dmladjenovic@wavecomp.com>
* config/mips/gnustack.h: Check for TARGET_LIBC_GNUSTACK also.
gcc/ChangeLog:
2020-01-23 Dragan Mladjenovic <dmladjenovic@wavecomp.com>
* config.in: Regenerated.
* config/mips/linux.h (NEED_INDICATE_EXEC_STACK): Define to 1
for TARGET_LIBC_GNUSTACK.
* configure: Regenerated.
* configure.ac: Define TARGET_LIBC_GNUSTACK if glibc version is
found to be 2.31 or greater.
PR tree-optimization/92924
* libgcov-profiler.c (__gcov_topn_values_profiler_body): First
try to find an existing value, then find an empty slot
if not found.
PR tree-optimization/92924
* profile.c (compute_value_histograms): Divide
all counter values.
PR tree-optimization/92924
* libgcov-driver.c (prune_topn_counter): New.
(prune_counters): Likewise.
(dump_one_gcov): Prune a run-time counter.
* libgcov-profiler.c (__gcov_topn_values_profiler_body):
For a known value, add GCOV_TOPN_VALUES to value.
Otherwise, decrement all counters by one.
* config/cris/arit.c (DS): Apply attribute fallthrough.
Without this, there are, for each compilation of arit.c, 30ish
occurrences of "this statement may fall through
[-Wimplicit-fallthrough=]", for lines that look like
case 32: DS; case 31: DS; case 30: DS; case 29: DS;
This patch is part of a patch series to add support for Armv8.1-M
Mainline Security Extensions architecture.
Code to detect whether cmse.c can be buit with -mcmse checks the output
of host GCC when invoked with -mcmse. However, an error from the
compiler does not prevent some minimal output so this always holds true.
2020-01-16 Mihail-Calin Ionescu <mihail.ionescu@arm.com>
2020-01-16 Thomas Preud'homme <thomas.preudhomme@arm.com>
* config/arm/t-arm: Check return value of gcc rather than lack of
output.
This changes introduces an internal API for VxWorks version checks
within runtime files, a prerequisite to a few fixes coming up for libstdc++
builds on more recent versions of the OS.
2019-12-30 Olivier Hainque <hainque@adacore.com>
gcc/
* config/vxworks/_vxworks-versions.h: New file.
* config.gcc (*-*-vxworks*): Add it to extra_headers.
libgcc/
* config/gthr-vxworks.h: Use _vxworks-versions.h.
* config/gthr-vxworks-tls.c: Likewise.
From-SVN: r279783
contrib/ChangeLog:
2019-12-16 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* config-list.mk: Add msp430-elfbare.
gcc/ChangeLog:
2019-12-16 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* config.gcc: s/msp430*-*-*/msp430-*-*.
Handle msp430-*-elfbare.
* config/msp430/msp430-devices.c (TARGET_SUBDIR): Define.
(_MSPMKSTR): Define.
(__MSPMKSTR): Define.
(rest_of_devices_path): Use TARGET_SUBDIR value in string.
* config/msp430/msp430.c (msp430_option_override): Error if
-fuse-cxa-atexit is used when it has been disabled at configure time.
* config/msp430/t-msp430: Define TARGET_SUBDIR when building
msp430-devices.o.
* doc/install.texi: Document msp430-*-elf and msp430-*-elfbare.
* doc/invoke.texi: Update documentation about which path devices.csv is
searched for.
gcc/testsuite/ChangeLog:
2019-12-16 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* g++.dg/init/dso_handle1.C: Require cxa_atexit support.
* g++.dg/init/dso_handle2.C: Likewise.
* g++.dg/other/cxa-atexit1.C: Likewise.
* gcc.target/msp430/msp430.exp: Update csv-using-installed.c test to
handle msp430-elfbare configuration.
libgcc/ChangeLog:
2019-12-16 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* config.host: s/msp430*-*-elf/msp430-*-elf*.
Override default "extra_parts" variable.
* configure: Regenerate.
* configure.ac: Disable TM clone registry by default for
msp430-elfbare.
From-SVN: r279442
ChangeLog:
2019-12-11 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* config-ml.in (msp430-*-*): Support --disable-no-exceptions configure
flag.
gcc/ChangeLog:
2019-12-11 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* config/msp430/msp430.h (STARTFILE_SPEC) [!fexceptions]: Use
crtbegin_no_eh.o if building for the C language.
[fno-exceptions]: Use crtbegin_no_eh.o if building for any language
except C.
(ENDFILE_SPEC) [!fexceptions]: Use crtend_no_eh.o if building for
the C language.
[fno-exceptions]: Use crtend_no_eh.o if building for any language
except C.
* config/msp430/t-msp430: Add -fno-exceptions multilib.
* doc/install.texi: Document --disable-no-exceptions multilib configure
option.
* doc/sourcebuild.texi: Document exceptions_enabled effective target.
gcc/testsuite/ChangeLog:
2019-12-11 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* lib/gcc-dg.exp: Add dg-prune messages for when exception handling is
disabled.
* lib/target-supports.exp (check_effective_target_exceptions_enabled):
New.
libgcc/ChangeLog:
2019-12-11 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* config.host: Add crt{begin,end}_no_eh.o to "extra_parts".
* config.host (msp430*-*-elf): Add crt{begin,end}_no_eh.o to
"extra_parts".
From-SVN: r279246
2019-12-09 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* crtstuff.c (__do_global_dtors_aux): Check if USE_EH_FRAME_REGISTRY is
defined instead of its value.
From-SVN: r279125
2019-12-09 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* crtstuff.c (__do_global_dtors_aux): Wrap in #if so it's only defined
if it will have contents.
From-SVN: r279123
The gthr weak reference based single thread detection is unsafe with
static linking and in case of dynamic linking it's ineffective on musl
since pthread symbols are defined in libc.so.
(Ideally this should be fixed for all targets, since glibc plans to move
libpthread.so into libc.so too and users want to static link to pthread
without --whole-archive: PR87189.)
For now we have to explicitly opt out from the broken behaviour in the
config machinery of each target lib and libgcc was previously missed.
libgcc/ChangeLog:
2019-11-18 Szabolcs Nagy <szabolcs.nagy@arm.com>
* config.host: Add t-gthr-noweak on *-*-musl*.
* config/t-gthr-noweak: New file.
From-SVN: r278399
Add the dynamic linker name and fix a type name to use the public name
instead of the glibc internal name.
gcc/ChangeLog:
2019-11-15 Szabolcs Nagy <szabolcs.nagy@arm.com>
* config/m68k/linux.h (MUSL_DYNAMIC_LINKER): Define.
libgcc/ChangeLog:
2019-11-15 Szabolcs Nagy <szabolcs.nagy@arm.com>
* config/m68k/linux-unwind.h (struct uw_ucontext): Use sigset_t instead
of __sigset_t.
From-SVN: r278312
2019-11-13 Jerome Lambourg <lambourg@adacore.com>
Doug Rupp <rupp@adacore.com>
Olivier Hainque <hainque@adacore.com>
gcc/
* config.gcc: Collapse the arm-vxworks entries into
a single arm-wrs-vxworks7* one, bpabi based. Update
the default cpu from arm8 to armv7-a
* config/arm/vxworks.h (CC1_SPEC): Simplify, knowing that
we always use ARM_UNWIND_INFO.
(DWARF2_UNWIND_INFO): Remove redefinition.
(ARM_TARGET2_DWARF_FORMAT): Likewise.
(VXWORKS_PERSONALITY): Define, to "llvm".
(VXWORKS_EXTRA_LIBS_RTP): Define, to "-lllvm".
libgcc/
* config.host: Collapse the arm-vxworks entries into
a single arm-wrs-vxworks7* one.
* config/arm/unwind-arm-vxworks.c: Update comments. Provide
__gnu_Unwind_Find_exidx and a weak dummy __cxa_type_match for
kernel modules, to be overriden by libstdc++ when we link with
it. Rely on externally provided __exidx_start/end.
Co-Authored-By: Doug Rupp <rupp@adacore.com>
Co-Authored-By: Olivier Hainque <hainque@adacore.com>
From-SVN: r278253
2019-11-12 Olivier Hainque <hainque@adacore.com>
libgcc/
* config/t-gthr-vxworksae: New file, add all the gthr-vxworks
sources except the cxx0x support to LIB2ADDEH. We don't support
cxx0x on AE/653.
* config/t-vxworksae: New file.
* config.host: Handle *-*-vxworksae: Add the two aforementioned
Makefile fragment files at their expected position in the tmake_file
list, in accordance with what is done for other VxWorks variants.
From-SVN: r278250
2019-11-12 Corentin Gay <gay@adacore.com>
Jerome Lambourg <lambourg@adacore.com>
Olivier Hainque <hainque@adacore.com>
libgcc/
* config/t-gthr-vxworks: New file, add all the gthr-vxworks
sources to LIB2ADDEH.
* config/t-vxworks: Remove adjustments to LIB2ADDEH.
* config/t-vxworks7: Likewise.
* config.host: Append a block at the end of the file to add the
t-gthr files to the tmake_file list for VxWorks after everything
else.
* config/vxlib.c: Rename as gthr-vxworks.c.
* config/vxlib-tls.c: Rename as gthr-vxworks-tls.c.
* config/gthr-vxworks.h: Simplify a few comments. Expose a TAS
API and a basic error checking API, both internal. Simplify the
__gthread_once_t type definition and initializers. Add sections
for condition variables support and for the C++0x thread support,
conditioned against Vx653 for the latter.
* config/gthr-vxworks.c (__gthread_once): Simplify comments and
implementation, leveraging the TAS internal API.
* config/gthr-vxworks-tls.c: Introduce an internal TLS data access
API, leveraging the general availability of TLS services in VxWorks7
post SR6xxx.
(__gthread_setspecific, __gthread_setspecific): Use it.
(tls_delete_hook): Likewise, and simplify the enter/leave dtor logic.
* config/gthr-vxworks-cond.c: New file. GTHREAD_COND variable
support based on VxWorks primitives.
* config/gthr-vxworks-thread.c: New file. GTHREAD_CXX0X support
based on VxWorks primitives.
Co-Authored-By: Jerome Lambourg <lambourg@adacore.com>
Co-Authored-By: Olivier Hainque <hainque@adacore.com>
From-SVN: r278249
2019-11-06 Jerome Lambourg <lambourg@adacore.com>
Olivier Hainque <hainque@adacore.com>
libgcc/
* config/vxcrtstuff.c: New file.
* config/t-vxcrtstuff: New Makefile fragment.
* config.host: Append t-vxcrtstuff to the tmake_file list
on all VxWorks ports using dwarf for table based EH.
gcc/
* config/vx-common.h (USE_TM_CLONE_REGISTRY): Remove
definition, pointless with a VxWorks specific version
of crtstuff.
(DWARF2_UNWIND_INFO): Conditionalize on !ARM_UNWIND_INFO.
* config/vxworks.h (VX_CRTBEGIN_SPEC, VX_CRTEND_SPEC):
New local macros, controlling the addition of vxworks specific
crtstuff objects depending on the EH mechanism and kind of
module being linked.
(VXWORKS_STARTFILE_SPEC, VXWORKS_ENDFILE_SPEC): Use them.
Co-Authored-By: Olivier Hainque <hainque@adacore.com>
From-SVN: r278248
gcc/
Support 64-bit double and 64-bit long double configurations.
PR target/92055
* config.gcc (tm_defines) [avr]: Set from --with-double=,
--with-long-double=.
* config/avr/t-multilib: Remove.
* config/avr/t-avr: Output of genmultilib.awk is now fully
dynamically generated and no more part of the repo.
(HAVE_DOUBLE_MULTILIB, HAVE_LONG_DOUBLE_MULTILIB): New variables.
Pass them down to...
* config/avr/genmultilib.awk: ...here and handle them.
* gcc/config/avr/avr.opt (-mdouble=, avr_double). New option and var.
(-mlong-double=, avr_long_double). New option and var.
* common/config/avr/avr-common.c (opts.h, diagnostic.h): Include.
(TARGET_OPTION_OPTIMIZATION_TABLE) <-mdouble=, -mlong-double=>:
Set default as requested by --with-double=
(TARGET_HANDLE_OPTION): Define to this...
(avr_handle_option): ...new hook worker.
* config/avr/avr.h (DOUBLE_TYPE_SIZE): Define to avr_double.
(LONG_DOUBLE_TYPE_SIZE): Define to avr_long_double.
(avr_double_lib): New proto for spec function.
(EXTRA_SPEC_FUNCTIONS) <double-lib>: Add.
(DRIVER_SELF_SPECS): Call %:double-lib.
* config/avr/avr.c (avr_option_override): Assert
sizeof(long double) >= sizeof(double) for the target.
* config/avr/avr-c.c (avr_cpu_cpp_builtins)
[__HAVE_DOUBLE_MULTILIB__, __HAVE_LONG_DOUBLE_MULTILIB__]
[__HAVE_DOUBLE64__, __HAVE_DOUBLE32__, __DEFAULT_DOUBLE__=]
[__HAVE_LONG_DOUBLE64__, __HAVE_LONG_DOUBLE32__]
[__HAVE_LONG_DOUBLE_IS_DOUBLE__, __DEFAULT_LONG_DOUBLE__=]:
New built-in define depending on --with-double=, --with-long-double=.
* config/avr/driver-avr.c (avr_double_lib): New spec function.
* doc/invoke.tex (AVR Options) <-mdouble=,-mlong-double=>: Doc.
* doc/install.texi (Cross-Compiler-Specific Options)
<--with-double=, --with-long-double=>: Doc.
libgcc/
Support 64-bit double and 64-bit long double configurations.
PR target/92055
* config/avr/t-avr (HOST_LIBGCC2_CFLAGS): Only add -DF=SF if
long double is a 32-bit type.
* config/avr/t-avrlibc: Copy double64 and long-double64
multilib(s) from the vanilla one.
* config/avr/t-copy-libgcc: New Makefile snip.
From-SVN: r277908
2019-11-04 Jozef Lawrynowicz <jozef.l@mittosystems.com>
* crtstuff.c: Define USE_TM_CLONE_REGISTRY to 0 if it's undefined and
the target output object format is not ELF.
s/defined(USE_TM_CLONE_REGISTRY)/USE_TM_CLONE_REGISTRY.
From-SVN: r277775
Using -mno-fdiv gives linker errors unless we build the missing divide
routines in libgcc always. There is at least one university project
designing RISC-V parts without FP divide that wants to use the option.
libgcc/
* config/riscv/t-softfp32 (softfp_extra): Add FP divide routines
From-SVN: r277723
* config/pa/fptr.c (_dl_read_access_allowed): Change argument to
unsigned int. Adjust callers.
(__canonicalize_funcptr_for_compare): Change plabel type to volatile
unsigned int *. Load relocation offset before function pointer.
Add barrier to ensure ordering.
From-SVN: r277015
* config/pa/lib2funcs.S (__gcc_plt_call): Load branch target to %r21.
Load PIC register after branch target. Fix white space.
* config/pa/milli64.S ($$dyncall): Separate LINUX and non LINUX
implementations. Load PIC register after branch target. Don't
clobber function pointer when it points to function descriptor.
Use nullification instead of branch in LINUX implementation.
From-SVN: r276925
