This patch updates the manual and adds a new chapter to the manual,
explaining types macros, constants and functions defined by ISO C11
threads.h standard.
[BZ# 14092]
* manual/debug.texi: Update adjacent chapter name.
* manual/probes.texi: Likewise.
* manual/threads.texi (ISO C Threads): New section.
(POSIX Threads): Convert to a section.
This patch adds to testsuite new test cases to test all new introduced
C11 threads functions, types and macros are tested.
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
Adhemerval Zanella <adhemerval.zanella@linaro.org>
Juan Manuel Torres Palma <jmtorrespalma@gmail.com>
[BZ #14092]
* nptl/Makefile (tests): Add new test files.
* nptl/tst-call-once.c : New file. Tests C11 functions and types.
* nptl/tst-cnd-basic.c: Likewise.
* nptl/tst-cnd-broadcast.c: Likewise.
* nptl/tst-cnd-timedwait.c: Likewise.
* nptl/tst-mtx-basic.c: Likewise.
* nptl/tst-mtx-recursive.c: Likewise.
* nptl/tst-mtx-timedlock.c: Likewise.
* nptl/tst-mtx-trylock.c: Likewise.
* nptl/tst-thrd-basic.c: Likewise.
* nptl/tst-thrd-detach.c: Likewise.
* nptl/tst-thrd-sleep.c: Likewise.
* nptl/tst-tss-basic.c: Likewise.
This patch adds the tss_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically tss_create, tss_delete, tss_get, tss_set, and required
types.
Mostly of the definitions are composed based on POSIX conterparts, including
tss_t (pthread_key_t).
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/data/threads.h-data (thread_local): New macro.
(TSS_DTOR_ITERATIONS): Likewise.
(tss_t): New type.
(tss_dtor_t): Likewise.
(tss_create): New function.
(tss_get): Likewise.
(tss_set): Likewise.
(tss_delete): Likewise.
* nptl/Makefile (libpthread-routines): Add tss_create, tss_delete,
tss_get, and tss_set objects.
* nptl/Versions (libpthread) [GLIBC_2.28]: Likewise.
* nptl/tss_create.c: New file.
* nptl/tss_delete.c: Likewise.
* nptl/tss_get.c: Likewise.
* nptl/tss_set.c: Likewise.
* sysdeps/nptl/threads.h (thread_local): New define.
(TSS_DTOR_ITERATIONS): Likewise.
(tss_t): New typedef.
(tss_dtor_t): Likewise.
(tss_create): New prototype.
(tss_get): Likewise.
(tss_set): Likewise.
(tss_delete): Likewise.
This patch adds the cnd_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically cnd_broadcast, cnd_destroy, cnd_init, cnd_signal,
cnd_timedwait, cnd_wait, and required types.
Mostly of the definitions are composed based on POSIX conterparts, and
cnd_t is also based on internal pthreads fields, but with distinct internal
layout to avoid possible issues with code interchange (such as trying to pass
POSIX structure on C11 functions and to avoid inclusion of pthread.h). The
idea is to make it possible to share POSIX internal implementation for mostly
of the code making adjust where only required.
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/data/threads.h-data (cnd_t): New type.
(cnd_init): New function.
(cnd_signal): Likewise.
(cnd_broadcast): Likewise.
(cnd_wait): Likewise.
(cnd_timedwait): Likewise.
(cnd_destroy): Likewise.
* nptl/Makefile (libpthread-routines): Add cnd_broadcast,
cnd_destroy, cnd_init, cnd_signal, cnd_timedwait, and cnd_wait
object.
* nptl/Versions (libpthread) [GLIBC_2.28]: Likewise.
* nptl/cnd_broadcast.c: New file.
* nptl/cnd_destroy.c: Likewise.
* nptl/cnd_init.c: Likewise.
* nptl/cnd_signal.c: Likewise.
* nptl/cnd_timedwait.c: Likewise.
* nptl/cnd_wait.c: Likewise.
* sysdeps/nptl/threads.h (cnd_t): New type.
(cnd_init): New prototype.
(cnd_signa): Likewise.
(cnd_broadcast): Likewise.
(cnd_wait): Likewise.
(cnd_timedwait): Likewise.
(cnd_destroy): Likewise.
This patch adds the call_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically call_once and required types.
Mostly of the definitions are composed based on POSIX conterparts,including
once_flag (pthread_once_t). The idea is to make possible to share POSIX
internal implementations for mostly of the code (and making adjustment only
when required).
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/data/threads.h-data (ONCE_FLAG_INIT): New macro.
(once_flag): New type.
(call_once): New function.
* nptl/Makefile (libpthread-routines): Add call_once object.
* nptl/Versions (libphread) [GLIBC_2.28]: Add call_once symbol.
* nptl/call_once.c: New file.
* sysdeps/nptl/threads.h (ONCE_FLAG_INIT): New define.
(once_flag): New type.
(call_once): New prototype.
This patch adds the mtx_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically mtx_init, mtx_destroy, mtx_lock, mtx_timedlock, mtx_trylock,
mtx_unlock, and required types.
Mostly of the definitions are composed based on POSIX conterparts, and mtx_t
is also based on internal pthread fields, but with a distinct internal layout
to avoid possible issues with code interchange (such as trying to pass POSIX
structure on C11 functions and to avoid inclusion of pthread.h). The idea
is to make possible to share POSIX internal implementations for mostly of
the code (and making adjustment only when required).
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/data/threads.h-data (mtx_plain): New constant.
(mtx_recursive): Likewise.
(mtx_timed): Likewise.
(mtx_t): New type.
(mtx_init): New function.
(mtx_lock): Likewise.
(mtx_timedlock): Likewise.
(mtx_trylock): Likewise.
(mtx_unlock): Likewise.
(mtx_destroy): Likewise.
* nptl/Makefile (libpthread-routines): Add mtx_destroy, mtx_init,
mtx_lock, mtx_timedlock, mtx_trylock, and mtx_unlock object.
* nptl/Versions (libpthread) [GLIBC_2.28]): Add mtx_init, mtx_lock,
mtx_timedlock, mtx_trylock, mtx_unlock, and mtx_destroy.
* nptl/mtx_destroy.c: New file.
* nptl/mtx_init.c: Likewise.
* nptl/mtx_lock.c: Likewise.
* nptl/mtx_timedlock.c: Likewise.
* nptl/mtx_trylock.c: Likewise.
* nptl/mtx_unlock.c: Likewise.
* sysdeps/nptl/threads.h (mtx_plain): New enumeration.
(mtx_recursive): Likewise.
(mtx_timed): Likewise.
(mtx_t): New type.
(mtx_init): New prototype.
(mtx_lock): Likewise.
(mtx_timedlock): Likewise.
(mtx_trylock): Likewise.
(mtx_unlock): Likewise.
(mtx_destroy): Likewise.
This patch adds the thrd_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically thrd_create, thrd_curent, rhd_detach, thrd_equal,
thrd_exit, thrd_join, thrd_sleep, thrd_yield, and required types.
Mostly of the definitions are composed based on POSIX conterparts, such as
thrd_t (using pthread_t). For thrd_* function internally direct
POSIX pthread call are used with the exceptions:
1. thrd_start uses pthread_create internal implementation, but changes
how to actually calls the start routine. This is due the difference
in signature between POSIX and C11, where former return a 'void *'
and latter 'int'.
To avoid calling convention issues due 'void *' to int cast, routines
from C11 threads are started slight different than default pthread one.
Explicit cast to expected return are used internally on pthread_create
and the result is stored back to void also with an explicit cast.
2. thrd_sleep uses nanosleep internal direct syscall to avoid clobbering
errno and to handle expected standard return codes. It is a
cancellation entrypoint to be consistent with both thrd_join and
cnd_{timed}wait.
3. thrd_yield also uses internal direct syscall to avoid errno clobbering.
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/Makefile (conformtest-headers-ISO11): Add threads.h.
(linknamespace-libs-ISO11): Add libpthread.a.
* conform/data/threads.h-data: New file: add C11 thrd_* types and
functions.
* include/stdc-predef.h (__STDC_NO_THREADS__): Remove definition.
* nptl/Makefile (headers): Add threads.h.
(libpthread-routines): Add new C11 thread thrd_create, thrd_current,
thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, and
thrd_yield.
* nptl/Versions (libpthread) [GLIBC_2.28]): Add new C11 thread
thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit,
thrd_join, thrd_sleep, and thrd_yield symbols.
* nptl/descr.h (struct pthread): Add c11 field.
* nptl/pthreadP.h (ATTR_C11_THREAD): New define.
* nptl/pthread_create.c (START_THREAD_DEFN): Call C11 thread start
routine with expected function prototype.
(__pthread_create_2_1): Add C11 threads check based on attribute
value.
* sysdeps/unix/sysdep.h (INTERNAL_SYSCALL_CANCEL): New macro.
* nptl/thrd_create.c: New file.
* nptl/thrd_current.c: Likewise.
* nptl/thrd_detach.c: Likewise.
* nptl/thrd_equal.c: Likewise.
* nptl/thrd_exit.c: Likewise.
* nptl/thrd_join.c: Likewise.
* nptl/thrd_priv.h: Likewise.
* nptl/thrd_sleep.c: Likewise.
* nptl/thrd_yield.c: Likewise.
* include/threads.h: Likewise.
Add <bits/indirect-return.h> and include it in <ucontext.h>.
__INDIRECT_RETURN defined in <bits/indirect-return.h> indicates if
swapcontext requires special compiler treatment. The default
__INDIRECT_RETURN is empty.
On x86, when shadow stack is enabled, __INDIRECT_RETURN is defined
with indirect_return attribute, which has been added to GCC 9, to
indicate that swapcontext returns via indirect branch. Otherwise
__INDIRECT_RETURN is defined with returns_twice attribute.
When shadow stack is enabled, remove always_inline attribute from
prepare_test_buffer in string/tst-xbzero-opt.c to avoid:
tst-xbzero-opt.c: In function ‘prepare_test_buffer’:
tst-xbzero-opt.c:105:1: error: function ‘prepare_test_buffer’ can never be inlined because it uses setjmp
prepare_test_buffer (unsigned char *buf)
when indirect_return attribute isn't available.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* bits/indirect-return.h: New file.
* misc/sys/cdefs.h (__glibc_has_attribute): New.
* sysdeps/x86/bits/indirect-return.h: Likewise.
* stdlib/Makefile (headers): Add bits/indirect-return.h.
* stdlib/ucontext.h: Include <bits/indirect-return.h>.
(swapcontext): Add __INDIRECT_RETURN.
* string/tst-xbzero-opt.c (ALWAYS_INLINE): New.
(prepare_test_buffer): Use it.
The shadow stack prevents us from pushing the saved return PC onto
the stack and returning normally. Instead we pop the shadow stack
and return directly. This is the safest way to return and ensures
any stack manipulations done by the vfork'd child doesn't cause the
parent to terminate when CET is enabled.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/i386/vfork.S (SYSCALL_ERROR_HANDLER):
Redefine if shadow stack is enabled.
(SYSCALL_ERROR_LABEL): Likewise.
(__vfork): Pop shadow stack and jump back to to caller directly
when shadow stack is in use.
* sysdeps/unix/sysv/linux/x86_64/vfork.S (SYSCALL_ERROR_HANDLER):
Redefine if shadow stack is enabled.
(SYSCALL_ERROR_LABEL): Likewise.
(__vfork): Pop shadow stack and jump back to to caller directly
when shadow stack is in use.
Add endbr64 to tst-quadmod1.S and tst-quadmod2.S so that func and foo
can be called indirectly.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/x86_64/tst-quadmod1.S (func): Add endbr64 if IBT is
enabled.
(foo): Likewise.
* sysdeps/x86_64/tst-quadmod2.S (func) : Likewise.
(foo): Likewise.
This bug is very similar to bug 23036: The existing code assumed that
the length count included the length byte itself.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* scripts/check-execstack.awk: Consider `xfail' variable containing a
list
of libraries whose stack executability is expected.
* elf/Makefile ($(objpfx)check-execstack.out): Pass
$(check-execstack-xfail) to check-execstack.awk through `xfail'
variable.
* sysdeps/mach/hurd/i386/Makefile (check-execstack-xfail): Set to ld.so
libc.so libpthread.so.
* sysdeps/mach/hurd/pipe2.c: New file, copy from pipe.c. Evolve it to
implement __pipe2.
* sysdeps/mach/hurd/pipe.c (__pipe): Reimplement using __pipe2.
The argparse library is used on compare_bench script to improve command line
argument parsing. The 'schema validation file' is now optional, reducing by
one the number of required parameters.
* benchtests/scripts/compare_bench.py (__main__): use the argparse
library to improve command line parsing.
(__main__): make schema file as optional parameter (--schema),
defaulting to benchtests/scripts/benchout.schema.json.
(main): move out of the parsing stuff to __main_ and leave it
only as caller of main comparison functions.
Multiple updates for Occitan language including alternative month names,
update abday and abmon, fix typos in day, fix d_fmt, correct LC_NAME,
and use “copy "ca_ES"” as LC_COLLATE.
[BZ #23140]
* localedata/locales/oc_FR (mon): Rename to...
(alt_mon): This, then update October (typo fix).
(mon): New content (genitive case, month names preceded by
"de" or "d’").
[BZ #23422]
* localedata/locales/oc_FR (abday): Update all items.
(day): Update Wednesday and Saturday (typo fixes).
(abmon): Update all items, except May.
(d_fmt): Update "%d.%m.%Y" -> "%d/%m/%Y".
(LC_IDENTIFICATION): Bump the revision number and date.
Keep the "category" entries in alphabetic order.
(LC_ADDRESS): Remove no longer needed comment.
(LC_COLLATE): Use “copy "ca_ES"”.
(LC_NAME): Set the correct values of "name_fmt", "name_mr", and
"name_mrs".
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Various glibc testcases use tmpnam in ways subject to race conditions
(generate a temporary file name, then later open that file without
O_EXCL).
This patch fixes those tests to use mkstemp - generally a minimal
local fix to use mkstemp instead of tmpnam, rather than a larger fix
to use other testsuite infrastructure for temporary files. The
unchanged use of tmpnam in posix/wordexp-test.c would fail safe in the
event of a race (it's generating a name for use with mkdir rather than
for a file to be opened for writing).
Tested for x86_64.
* grp/tst_fgetgrent.c: Include <unistd.h>.
(main): Use mkstemp instead of tmpnam.
* io/test-utime.c (main): Likewise.
* posix/annexc.c (macrofile): Change to modifiable array.
(get_null_defines): Use mkstemp instead of tmpnam. Do not remove
macrofile here.
* posix/bug-getopt1.c: Include <stdlib.h>.
(do_test): Use mkstemp instead of tmpnam.
* posix/bug-getopt2.c: Include <stdlib.h>.
(do_test): Use mkstemp instead of tmpnam.
* posix/bug-getopt3.c: Include <stdlib.h>.
(do_test): Use mkstemp instead of tmpnam.
* posix/bug-getopt4.c: Include <stdlib.h>.
(do_test): Use mkstemp instead of tmpnam.
* posix/bug-getopt5.c: Include <stdlib.h>.
(do_test): Use mkstemp instead of tmpnam.
* stdio-common/bug7.c: Include <stdlib.h> and <unistd.h>.
(main): Use mkstemp instead of tmpnam.
* stdio-common/tst-fdopen.c: Include <stdlib.h>.
(main): Use mkstemp instead of tmpnam.
* stdio-common/tst-ungetc.c: Include <stdlib.h>.
(main): use mkstemp instead of tmpnam.
* stdlib/isomac.c (macrofile): Change to modifiable array.
(get_null_defines): Use mkstemp instead of tmpnam. Do not remove
macrofile here.
i386 add_n.S and sub_n.S use a trick to implment jump tables with LEA.
We can't use conditional branches nor normal jump tables since jump
table entries use EFLAGS set by jump table index. This patch adds
_CET_ENDBR to indirect jump targets and adjust destination for
_CET_ENDBR.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/add_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_add_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
* sysdeps/i386/i686/add_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_add_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
* sysdeps/i386/sub_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_sub_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
Add _CET_ENDBR to STRCMP_SSE42, which is called indirectly, to support
IBT.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/x86_64/multiarch/strcmp-sse42.S (STRCMP_SSE42): Add
_CET_ENDBR.
Add _CET_ENDBR to functions in crti.S, which are called indirectly, to
support IBT.
Tested on i686 and x86-64.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/crti.S (_init): Add _CET_ENDBR.
(_fini): Likewise.
* sysdeps/x86_64/crti.S (_init): Likewise.
(_fini): Likewise.
Always include <dl-cet.h> and cet-tunables.h> when CET is enabled.
Otherwise, configure glibc with --enable-cet --disable-tunables will
fail to build.
* sysdeps/x86/cpu-features.c: Always include <dl-cet.h> and
cet-tunables.h> when CET is enabled.
Intel Control-flow Enforcement Technology (CET) instructions:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-en
forcement-technology-preview.pdf
includes Indirect Branch Tracking (IBT) and Shadow Stack (SHSTK).
GNU_PROPERTY_X86_FEATURE_1_IBT is added to GNU program property to
indicate that all executable sections are compatible with IBT when
ENDBR instruction starts each valid target where an indirect branch
instruction can land. Linker sets GNU_PROPERTY_X86_FEATURE_1_IBT on
output only if it is set on all relocatable inputs.
On an IBT capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable IBT and
lock IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the executable.
2. When loading an executable with an interpreter, enable IBT if
GNU_PROPERTY_X86_FEATURE_1_IBT is set on the interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_IBT isn't set on the executable,
disable IBT.
b. Lock IBT.
3. If IBT is enabled, when loading a shared object without
GNU_PROPERTY_X86_FEATURE_1_IBT:
a. If legacy interwork is allowed, then mark all pages in executable
PT_LOAD segments in legacy code page bitmap. Failure of legacy code
page bitmap allocation causes an error.
b. If legacy interwork isn't allowed, it causes an error.
GNU_PROPERTY_X86_FEATURE_1_SHSTK is added to GNU program property to
indicate that all executable sections are compatible with SHSTK where
return address popped from shadow stack always matches return address
popped from normal stack. Linker sets GNU_PROPERTY_X86_FEATURE_1_SHSTK
on output only if it is set on all relocatable inputs.
On a SHSTK capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on the executable.
2. When loading an executable with an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_SHSTK isn't set on the executable
or any shared objects loaded via the DT_NEEDED tag, disable SHSTK.
b. Otherwise lock SHSTK.
3. After SHSTK is enabled, it is an error to load a shared object
without GNU_PROPERTY_X86_FEATURE_1_SHSTK.
To enable CET support in glibc, --enable-cet is required to configure
glibc. When CET is enabled, both compiler and assembler must support
CET. Otherwise, it is a configure-time error.
To support CET run-time control,
1. _dl_x86_feature_1 is added to the writable ld.so namespace to indicate
if IBT or SHSTK are enabled at run-time. It should be initialized by
init_cpu_features.
2. For dynamic executables:
a. A l_cet field is added to struct link_map to indicate if IBT or
SHSTK is enabled in an ELF module. _dl_process_pt_note or
_rtld_process_pt_note is called to process PT_NOTE segment for
GNU program property and set l_cet.
b. _dl_open_check is added to check IBT and SHSTK compatibilty when
dlopening a shared object.
3. Replace i386 _dl_runtime_resolve and _dl_runtime_profile with
_dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, respectively if
SHSTK is enabled.
CET run-time control can be changed via GLIBC_TUNABLES with
$ export GLIBC_TUNABLES=glibc.tune.x86_shstk=[permissive|on|off]
$ export GLIBC_TUNABLES=glibc.tune.x86_ibt=[permissive|on|off]
1. permissive: SHSTK is disabled when dlopening a legacy ELF module.
2. on: IBT or SHSTK are always enabled, regardless if there are IBT or
SHSTK bits in GNU program property.
3. off: IBT or SHSTK are always disabled, regardless if there are IBT or
SHSTK bits in GNU program property.
<cet.h> from CET-enabled GCC is automatically included by assembly codes
to add GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK
to GNU program property. _CET_ENDBR is added at the entrance of all
assembly functions whose address may be taken. _CET_NOTRACK is used to
insert NOTRACK prefix with indirect jump table to support IBT. It is
defined as notrack when _CET_NOTRACK is defined in <cet.h>.
[BZ #21598]
* configure.ac: Add --enable-cet.
* configure: Regenerated.
* elf/Makefille (all-built-dso): Add a comment.
* elf/dl-load.c (filebuf): Moved before "dynamic-link.h".
Include <dl-prop.h>.
(_dl_map_object_from_fd): Call _dl_process_pt_note on PT_NOTE
segment.
* elf/dl-open.c: Include <dl-prop.h>.
(dl_open_worker): Call _dl_open_check.
* elf/rtld.c: Include <dl-prop.h>.
(dl_main): Call _rtld_process_pt_note on PT_NOTE segment. Call
_rtld_main_check.
* sysdeps/generic/dl-prop.h: New file.
* sysdeps/i386/dl-cet.c: Likewise.
* sysdeps/unix/sysv/linux/x86/cpu-features.c: Likewise.
* sysdeps/unix/sysv/linux/x86/dl-cet.h: Likewise.
* sysdeps/x86/cet-tunables.h: Likewise.
* sysdeps/x86/check-cet.awk: Likewise.
* sysdeps/x86/configure: Likewise.
* sysdeps/x86/configure.ac: Likewise.
* sysdeps/x86/dl-cet.c: Likewise.
* sysdeps/x86/dl-procruntime.c: Likewise.
* sysdeps/x86/dl-prop.h: Likewise.
* sysdeps/x86/libc-start.h: Likewise.
* sysdeps/x86/link_map.h: Likewise.
* sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
(_dl_runtime_resolve_shstk): New.
(_dl_runtime_profile_shstk): Likewise.
* sysdeps/linux/x86/Makefile (sysdep-dl-routines): Add dl-cet
if CET is enabled.
(CFLAGS-.o): Add -fcf-protection if CET is enabled.
(CFLAGS-.os): Likewise.
(CFLAGS-.op): Likewise.
(CFLAGS-.oS): Likewise.
(asm-CPPFLAGS): Add -fcf-protection -include cet.h if CET
is enabled.
(tests-special): Add $(objpfx)check-cet.out.
(cet-built-dso): New.
(+$(cet-built-dso:=.note)): Likewise.
(common-generated): Add $(cet-built-dso:$(common-objpfx)%=%.note).
($(objpfx)check-cet.out): New.
(generated): Add check-cet.out.
* sysdeps/x86/cpu-features.c: Include <dl-cet.h> and
<cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New prototype.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
(init_cpu_features): Call get_cet_status to check CET status
and update dl_x86_feature_1 with CET status. Call
TUNABLE_CALLBACK (set_x86_ibt) and TUNABLE_CALLBACK
(set_x86_shstk). Disable and lock CET in libc.a.
* sysdeps/x86/cpu-tunables.c: Include <cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New function.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
* sysdeps/x86/sysdep.h (_CET_NOTRACK): New.
(_CET_ENDBR): Define if not defined.
(ENTRY): Add _CET_ENDBR.
* sysdeps/x86/dl-tunables.list (glibc.tune): Add x86_ibt and
x86_shstk.
* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
