Commit Graph

16051 Commits

Author SHA1 Message Date
Andreas Schwab
6edaa12b41 riscv: add support for static PIE
In order to support static PIE the startup code must avoid relocations
before __libc_start_main is called.
2024-01-22 14:58:23 +01:00
Adhemerval Zanella
bcf2abd43b sh: Fix static build with --enable-fortify
For static the internal symbols should not be prepended with the
internal __GI_.

Checked with a make check for sh4-linux-gnu.
2024-01-22 10:04:53 -03:00
Adhemerval Zanella
926a4bdbb5 sparc: Fix sparc64 memmove length comparison (BZ 31266)
The small counts copy bytes comparsion should be unsigned (as the
memmove size argument).  It fixes string/tst-memmove-overflow on
sparcv9, where the input size triggers an invalid code path.

Checked on sparc64-linux-gnu and sparcv9-linux-gnu.
2024-01-22 09:34:50 -03:00
Adhemerval Zanella
369efd8177 sparc64: Remove unwind information from signal return stubs [BZ#31244]
Similar to sparc32 fix, remove the unwind information on the signal
return stubs.  This fixes the regressions:

FAIL: nptl/tst-cancel24-static
FAIL: nptl/tst-cond8-static
FAIL: nptl/tst-mutex8-static
FAIL: nptl/tst-mutexpi8-static
FAIL: nptl/tst-mutexpi9

On sparc64-linux-gnu.
2024-01-22 09:34:50 -03:00
Adhemerval Zanella
dd57f5e7b6 sparc: Remove 64 bit check on sparc32 wordsize (BZ 27574)
The sparc32 is always 32 bits.

Checked on sparcv9-linux-gnu.
2024-01-22 09:34:50 -03:00
Daniel Cederman
87d921e270 sparc: Do not test preservation of NaN payloads for LEON
The FPU used by LEON does not preserve NaN payload. This change allows
the math/test-*-canonicalize tests to pass on LEON.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-18 08:27:44 -03:00
Daniel Cederman
45f7ea26c1 sparc: Force calculation that raises exception
Use the math_force_eval() macro to force the calculation to complete and
raise the exception.

With this change the math/test-fenv test pass.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-18 08:27:44 -03:00
Daniel Cederman
a8f7c77970 sparc: Fix llrint and llround missing exceptions on SPARC V8
Conversions from a float to a long long on SPARC v8 uses a libgcc function
that may not raise the correct exceptions on overflow. It also may raise
spurious "inexact" exceptions on non overflow cases. This patch fixes the
problem in the same way as for RV32.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-18 08:27:44 -03:00
Daniel Cederman
7bd06985c0 sparc: Remove unwind information from signal return stubs [BZ #31244]
The functions were previously written in C, but were not compiled
with unwind information. The ENTRY/END macros includes .cfi_startproc
and .cfi_endproc which adds unwind information. This caused the
tests cleanup-8 and cleanup-10 in the GCC testsuite to fail.
This patch adds a version of the ENTRY/END macros without the
CFI instructions that can be used instead.

sigaction registers a restorer address that is located two instructions
before the stub function. This patch adds a two instruction padding to
avoid that the unwinder accesses the unwind information from the function
that the linker has placed right before it in memory. This fixes an issue
with pthread_cancel that caused tst-mutex8-static (and other tests) to fail.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-18 08:27:44 -03:00
Daniel Cederman
82a35070ec sparc: Prevent stfsr from directly following floating-point instruction
On LEON, if the stfsr instruction is immediately following a floating-point
operation instruction in a running program, with no other instruction in
between the two, the stfsr might behave as if the order was reversed
between the two instructions and the stfsr occurred before the
floating-point operation.

Add a nop instruction before the stfsr to prevent this from happening.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-18 08:27:44 -03:00
Daniel Cederman
3bb1350c36 sparc: Use existing macros to avoid code duplication
Macros for using inline assembly to access the fp state register exists
in both fenv_private.h and in fpu_control.h. Let fenv_private.h use the
macros from fpu_control.h

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-18 08:27:43 -03:00
Joseph Myers
6511b579a5 Update kernel version to 6.7 in header constant tests
This patch updates the kernel version in the tests tst-mman-consts.py,
tst-mount-consts.py and tst-pidfd-consts.py to 6.7.  (There are no new
constants covered by these tests in 6.7 that need any other header
changes.)

Tested with build-many-glibcs.py.
2024-01-17 21:15:37 +00:00
Joseph Myers
df11c05be9 Update syscall lists for Linux 6.7
Linux 6.7 adds the futex_requeue, futex_wait and futex_wake syscalls,
and enables map_shadow_stack for architectures previously missing it.
Update syscall-names.list and regenerate the arch-syscall.h headers
with build-many-glibcs.py update-syscalls.

Tested with build-many-glibcs.py.
2024-01-17 15:38:54 +00:00
H.J. Lu
457bd9cf2e x86-64: Check if mprotect works before rewriting PLT
Systemd execution environment configuration may prohibit changing a memory
mapping to become executable:

MemoryDenyWriteExecute=
Takes a boolean argument. If set, attempts to create memory mappings
that are writable and executable at the same time, or to change existing
memory mappings to become executable, or mapping shared memory segments
as executable, are prohibited.

When it is set, systemd service stops working if PLT rewrite is enabled.
Check if mprotect works before rewriting PLT.  This fixes BZ #31230.
This also works with SELinux when deny_execmem is on.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-01-15 06:59:23 -08:00
Sunil K Pandey
9d94997b5f x86_64: Optimize ffsll function code size.
Ffsll function randomly regress by ~20%, depending on how code gets
aligned in memory.  Ffsll function code size is 17 bytes.  Since default
function alignment is 16 bytes, it can load on 16, 32, 48 or 64 bytes
aligned memory.  When ffsll function load at 16, 32 or 64 bytes aligned
memory, entire code fits in single 64 bytes cache line.  When ffsll
function load at 48 bytes aligned memory, it splits in two cache line,
hence random regression.

Ffsll function size reduction from 17 bytes to 12 bytes ensures that it
will always fit in single 64 bytes cache line.

This patch fixes ffsll function random performance regression.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-01-13 12:20:08 -08:00
Yanzhang Wang
e0590f41fe RISC-V: Enable static-pie.
This patch referents the commit 374cef3 to add static-pie support. And
because the dummy link map is used when relocating ourselves, so need
not to set __global_pointer$ at this time.

It will also check whether toolchain supports to build static-pie.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-12 15:11:45 -03:00
Adhemerval Zanella
061eaf0244 linux: Fix fstat64 on alpha and sparc64
The 551101e824 change is incorrect for
alpha and sparc, since __NR_stat is defined by both kABI.  Use
__NR_newfstat to check whether to fallback to __NR_fstat64 (similar
to what fstatat64 does).

Checked on sparc64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-01-12 15:11:11 -03:00
Wilco Dijkstra
08ddd26814 math: remove exp10 wrappers
Remove the error handling wrapper from exp10.  This is very similar to
the changes done to exp and exp2, except that we also need to handle
pow10 and pow10l.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-12 16:02:12 +00:00
Xi Ruoyao
5a85786a90
Make __getrandom_nocancel set errno and add a _nostatus version
The __getrandom_nocancel function returns errors as negative values
instead of errno.  This is inconsistent with other _nocancel functions
and it breaks "TEMP_FAILURE_RETRY (__getrandom_nocancel (p, n, 0))" in
__arc4random_buf.  Use INLINE_SYSCALL_CALL instead of
INTERNAL_SYSCALL_CALL to fix this issue.

But __getrandom_nocancel has been avoiding from touching errno for a
reason, see BZ 29624.  So add a __getrandom_nocancel_nostatus function
and use it in tcache_key_initialize.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
2024-01-12 14:23:11 +01:00
H.J. Lu
f2b65a4471 x86-64/cet: Make CET feature check specific to Linux/x86
CET feature bits in TCB, which are Linux specific, are used to check if
CET features are active.  Move CET feature check to Linux/x86 directory.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-01-11 20:35:24 -08:00
H.J. Lu
874214db62 i386: Remove CET support bits
1. Remove _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk.
2. Move CET offsets from x86 cpu-features-offsets.sym to x86-64
features-offsets.sym.
3. Rename x86 cet-control.h to x86-64 feature-control.h since it is only
for x86-64 and also used for PLT rewrite.
4. Add x86-64 ldsodefs.h to include feature-control.h.
5. Change TUNABLE_CALLBACK (set_plt_rewrite) to x86-64 only.
6. Move x86 dl-procruntime.c to x86-64.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-10 05:20:20 -08:00
H.J. Lu
7d544dd049 x86-64/cet: Move check-cet.awk to x86_64
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-10 05:20:16 -08:00
H.J. Lu
a1bbee9fd1 x86-64/cet: Move dl-cet.[ch] to x86_64 directories
Since CET is only enabled for x86-64, move dl-cet.[ch] to x86_64
directories.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-10 05:19:32 -08:00
H.J. Lu
b45115a666 x86: Move x86-64 shadow stack startup codes
Move sysdeps/x86/libc-start.h to sysdeps/x86_64/libc-start.h and use
sysdeps/generic/libc-start.h for i386.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-10 05:19:32 -08:00
Adhemerval Zanella
a0cfc48e8a i386: Fail if configured with --enable-cet
Since it is only supported for x86_64.

Checked on i686-linux-gnu.
2024-01-09 13:55:51 -03:00
Adhemerval Zanella
25f1e16ef0 i386: Remove CET support
CET is only support for x86_64, this patch reverts:

  - faaee1f07e x86: Support shadow stack pointer in setjmp/longjmp.
  - be9ccd27c0 i386: Add _CET_ENDBR to indirect jump targets in
    add_n.S/sub_n.S
  - c02695d776 x86/CET: Update vfork to prevent child return
  - 5d844e1b72 i386: Enable CET support in ucontext functions
  - 124bcde683 x86: Add _CET_ENDBR to functions in crti.S
  - 562837c002 x86: Add _CET_ENDBR to functions in dl-tlsdesc.S
  - f753fa7dea x86: Support IBT and SHSTK in Intel CET [BZ #21598]
  - 825b58f3fb i386-mcount.S: Add _CET_ENDBR to _mcount and __fentry__
  - 7e119cd582 i386: Use _CET_NOTRACK in i686/memcmp.S
  - 177824e232 i386: Use _CET_NOTRACK in memcmp-sse4.S
  - 0a899af097 i386: Use _CET_NOTRACK in memcpy-ssse3-rep.S
  - 7fb613361c i386: Use _CET_NOTRACK in memcpy-ssse3.S
  - 77a8ae0948 i386: Use _CET_NOTRACK in memset-sse2-rep.S
  - 00e7b76a8f i386: Use _CET_NOTRACK in memset-sse2.S
  - 90d15dc577 i386: Use _CET_NOTRACK in strcat-sse2.S
  - f1574581c7 i386: Use _CET_NOTRACK in strcpy-sse2.S
  - 4031d7484a i386/sub_n.S: Add a missing _CET_ENDBR to indirect jump
  - target
  -
Checked on i686-linux-gnu.
2024-01-09 13:55:51 -03:00
Adhemerval Zanella
b7fc4a07f2 x86: Move CET infrastructure to x86_64
The CET is only supported for x86_64 and there is no plan to add
kernel support for i386.  Move the Makefile rules and files from the
generic x86 folder to x86_64 one.

Checked on x86_64-linux-gnu and i686-linux-gnu.
2024-01-09 13:55:51 -03:00
Adhemerval Zanella
460860f457 Remove ia64-linux-gnu
Linux 6.7 removed ia64 from the official tree [1], following the general
principle that a glibc port needs upstream support for the architecture
in all the components it depends on (binutils, GCC, and the Linux
kernel).

Apart from the removal of sysdeps/ia64 and sysdeps/unix/sysv/linux/ia64,
there are updates to various comments referencing ia64 for which removal
of those references seemed appropriate. The configuration is removed
from README and build-many-glibcs.py.

The CONTRIBUTED-BY, elf/elf.h, manual/contrib.texi (the porting
mention), *.po files, config.guess, and longlong.h are not changed.

For Linux it allows cleanup some clone2 support on multiple files.

The following bug can be closed as WONTFIX: BZ 22634 [2], BZ 14250 [3],
BZ 21634 [4], BZ 10163 [5], BZ 16401 [6], and BZ 11585 [7].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=43ff221426d33db909f7159fdf620c3b052e2d1c
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=22634
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=14250
[4] https://sourceware.org/bugzilla/show_bug.cgi?id=21634
[5] https://sourceware.org/bugzilla/show_bug.cgi?id=10163
[6] https://sourceware.org/bugzilla/show_bug.cgi?id=16401
[7] https://sourceware.org/bugzilla/show_bug.cgi?id=11585
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-01-08 17:09:36 -03:00
H.J. Lu
0f9afc265a x32: Handle displacement overflow in PLT rewrite [BZ #31218]
PLT rewrite calculated displacement with

ElfW(Addr) disp = value - branch_start - JMP32_INSN_SIZE;

On x32, displacement from 0xf7fbe060 to 0x401030 was calculated as

unsigned int disp = 0x401030 - 0xf7fbe060 - 5;

with disp == 0x8442fcb and caused displacement overflow. The PLT entry
was changed to:

0xf7fbe060 <+0>:	e9 cb 2f 44 08     	jmp    0x401030
0xf7fbe065 <+5>:	cc                 	int3
0xf7fbe066 <+6>:	cc                 	int3
0xf7fbe067 <+7>:	cc                 	int3
0xf7fbe068 <+8>:	cc                 	int3
0xf7fbe069 <+9>:	cc                 	int3
0xf7fbe06a <+10>:	cc                 	int3
0xf7fbe06b <+11>:	cc                 	int3
0xf7fbe06c <+12>:	cc                 	int3
0xf7fbe06d <+13>:	cc                 	int3
0xf7fbe06e <+14>:	cc                 	int3
0xf7fbe06f <+15>:	cc                 	int3

x32 has 32-bit address range, but it doesn't wrap address around at 4GB,
JMP target was changed to 0x100401030 (0xf7fbe060LL + 0x8442fcbLL + 5),
which is above 4GB.

Always use uint64_t to calculate displacement.  This fixes BZ #31218.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-01-06 14:25:49 -08:00
Noah Goldstein
b96a2eba2f x86: Fixup some nits in longjmp asm implementation
Replace a stray `nop` with a `.p2align` directive.
2024-01-05 18:00:38 -08:00
H.J. Lu
848746e88e elf: Add ELF_DYNAMIC_AFTER_RELOC to rewrite PLT
Add ELF_DYNAMIC_AFTER_RELOC to allow target specific processing after
relocation.

For x86-64, add

 #define DT_X86_64_PLT     (DT_LOPROC + 0)
 #define DT_X86_64_PLTSZ   (DT_LOPROC + 1)
 #define DT_X86_64_PLTENT  (DT_LOPROC + 3)

1. DT_X86_64_PLT: The address of the procedure linkage table.
2. DT_X86_64_PLTSZ: The total size, in bytes, of the procedure linkage
table.
3. DT_X86_64_PLTENT: The size, in bytes, of a procedure linkage table
entry.

With the r_addend field of the R_X86_64_JUMP_SLOT relocation set to the
memory offset of the indirect branch instruction.

Define ELF_DYNAMIC_AFTER_RELOC for x86-64 to rewrite the PLT section
with direct branch after relocation when the lazy binding is disabled.

PLT rewrite is disabled by default since SELinux may disallow modifying
code pages and ld.so can't detect it in all cases.  Use

$ export GLIBC_TUNABLES=glibc.cpu.plt_rewrite=1

to enable PLT rewrite with 32-bit direct jump at run-time or

$ export GLIBC_TUNABLES=glibc.cpu.plt_rewrite=2

to enable PLT rewrite with 32-bit direct jump and on APX processors with
64-bit absolute jump at run-time.

Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-01-05 05:49:49 -08:00
Sergey Bugaev
520b1df08d aarch64: Make cpu-features definitions not Linux-specific
These describe generic AArch64 CPU features, and are not tied to a
kernel-specific way of determining them. We can share them between
the Linux and Hurd AArch64 ports.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-13-bugaevc@gmail.com>
2024-01-04 23:48:54 +01:00
Sergey Bugaev
fbfe0b20ab hurd: Initializy _dl_pagesize early in static builds
We fetch __vm_page_size as the very first RPC that we do, inside
__mach_init (). Propagate that to _dl_pagesize ASAP after that,
before any other initialization.

In dynamic builds, this is already done immediately after
__mach_init (), inside _dl_sysdep_start ().

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-12-bugaevc@gmail.com>
2024-01-04 23:48:36 +01:00
Sergey Bugaev
4145de65f6 hurd: Only init early static TLS if it's used to store stack or pointer guards
This is the case on both x86 architectures, but not on AArch64.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-11-bugaevc@gmail.com>
2024-01-04 23:48:23 +01:00
Sergey Bugaev
9eaa0e1799 hurd: Make init-first.c no longer x86-specific
This will make it usable in other ports.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-10-bugaevc@gmail.com>
2024-01-04 23:48:07 +01:00
Sergey Bugaev
b44ad8944b hurd: Drop x86-specific assembly from init-first.c
We already have the RETURN_TO macro for this exact use case, and it's already
used in the non-static code path. Use it here too.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-9-bugaevc@gmail.com>
2024-01-04 23:47:23 +01:00
Sergey Bugaev
24b707c166 hurd: Pass the data pointer to _hurd_stack_setup explicitly
Instead of relying on the stack frame layout to figure out where the stack
pointer was prior to the _hurd_stack_setup () call, just pass the pointer
as an argument explicitly. This is less brittle and much more portable.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-8-bugaevc@gmail.com>
2024-01-04 23:47:03 +01:00
H.J. Lu
35694d3416 x86-64/cet: Check the restore token in longjmp
setcontext and swapcontext put a restore token on the old shadow stack
which is used to restore the target shadow stack when switching user
contexts.  When longjmp from a user context, the target shadow stack
can be different from the current shadow stack and INCSSP can't be
used to restore the shadow stack pointer to the target shadow stack.

Update longjmp to search for a restore token.  If found, use the token
to restore the shadow stack pointer before using INCSSP to pop the
shadow stack.  Stop the token search and use INCSSP if the shadow stack
entry value is the same as the current shadow stack pointer.

It is a user error if there is a shadow stack switch without leaving a
restore token on the old shadow stack.

The only difference between __longjmp.S and __longjmp_chk.S is that
__longjmp_chk.S has a check for invalid longjmp usages.  Merge
__longjmp.S and __longjmp_chk.S by adding the CHECK_INVALID_LONGJMP
macro.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-01-04 13:38:26 -08:00
H.J. Lu
bbfb54930c i386: Ignore --enable-cet
Since shadow stack is only supported for x86-64, ignore --enable-cet for
i386.  Always setting $(enable-cet) for i386 to "no" to support

ifneq ($(enable-cet),no)

in x86 Makefiles.  We can't use

ifeq ($(enable-cet),yes)

since $(enable-cet) can be "yes", "no" or "permissive".
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-04 06:08:55 -08:00
Sergey Bugaev
0d4a2f3576 mach: Drop SNARF_ARGS macro
We're obtaining arguments from the stack differently, see init-first.c.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
2024-01-03 21:59:55 +01:00
Sergey Bugaev
114de961e0 mach: Drop some unnecessary vm_param.h includes
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
2024-01-03 21:59:54 +01:00
Sergey Bugaev
dac7c64065 hurd: Add some missing includes
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
2024-01-03 21:59:54 +01:00
Joseph Myers
b34b46b880 Implement C23 <stdbit.h>
C23 adds a header <stdbit.h> with various functions and type-generic
macros for bit-manipulation of unsigned integers (plus macro defines
related to endianness).  Implement this header for glibc.

The functions have both inline definitions in the header (referenced
by macros defined in the header) and copies with external linkage in
the library (which are implemented in terms of those macros to avoid
duplication).  They are documented in the glibc manual.  Tests, as
well as verifying results for various inputs (of both the macros and
the out-of-line functions), verify the types of those results (which
showed up a bug in an earlier version with the type-generic macro
stdc_has_single_bit wrongly returning a promoted type), that the
macros can be used at top level in a source file (so don't use ({})),
that they evaluate their arguments exactly once, and that the macros
for the type-specific functions have the expected implicit conversions
to the relevant argument type.

Jakub previously referred to -Wconversion warnings in type-generic
macros, so I've included a test with -Wconversion (but the only
warnings I saw and fixed from that test were actually in inline
functions in the <stdbit.h> header - not anything coming from use of
the type-generic macros themselves).

This implementation of the type-generic macros does not handle
unsigned __int128, or unsigned _BitInt types with a width other than
that of a standard integer type (and C23 doesn't require the header to
handle such types either).  Support for those types, using the new
type-generic built-in functions Jakub's added for GCC 14, can
reasonably be added in a followup (along of course with associated
tests).

This implementation doesn't do anything special to handle C++, or have
any tests of functionality in C++ beyond the existing tests that all
headers can be compiled in C++ code; it's not clear exactly what form
this header should take in C++, but probably not one using macros.

DIS ballot comment AT-107 asks for the word "count" to be added to the
names of the stdc_leading_zeros, stdc_leading_ones,
stdc_trailing_zeros and stdc_trailing_ones functions and macros.  I
don't think it's likely to be accepted (accepting any technical
comments would mean having an FDIS ballot), but if it is accepted at
the WG14 meeting (22-26 January in Strasbourg, starting with DIS
ballot comment handling) then there would still be time to update
glibc for the renaming before the 2.39 release.

The new functions and header are placed in the stdlib/ directory in
glibc, rather than creating a new toplevel stdbit/ or putting them in
string/ alongside ffs.

Tested for x86_64 and x86.
2024-01-03 12:07:14 +00:00
Szabolcs Nagy
0c12c8c0cb aarch64: Add longjmp test for SME
Includes test for setcontext too.

The test directly checks after longjmp if ZA got disabled and the
ZA contents got saved following the lazy saving scheme. It does not
use ACLE code to verify that gcc can interoperate with glibc.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-02 16:54:21 +00:00
Szabolcs Nagy
9d30e5cf96 aarch64: Add setcontext support for SME
For the ZA lazy saving scheme to work, setcontext has to call
__libc_arm_za_disable.

Also fixes swapcontext which uses setcontext internally.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-02 15:43:30 +00:00
Szabolcs Nagy
a7373e457f aarch64: Add longjmp support for SME
For the ZA lazy saving scheme to work, longjmp has to call
__libc_arm_za_disable.

In ld.so we assume ZA is not used so longjmp does not need
special support there.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-02 15:43:30 +00:00
Szabolcs Nagy
d3c32ae207 aarch64: Add SME runtime support
The runtime support routines for the call ABI of the Scalable Matrix
Extension (SME) are mostly in libgcc. Since libc.so cannot depend on
libgcc_s.so have an implementation of __arm_za_disable in libc for
libc internal use in longjmp and similar APIs.

__libc_arm_za_disable follows the same PCS rules as __arm_za_disable,
but it's a hidden symbol so it does not need variant PCS marking.

Using __libc_fatal instead of abort because it can print a message and
works in ld.so too. But for now we don't need SME routines in ld.so.

To check the SME HWCAP in asm, we need the _dl_hwcap2 member offset in
_rtld_global_ro in the shared libc.so, while in libc.a the _dl_hwcap2
object is accessed.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-02 15:43:30 +00:00
H.J. Lu
b5dcccfb12 x86/cet: Add -fcf-protection=none before -fcf-protection=branch
When shadow stack is enabled, some CET tests failed when compiled with
GCC 14:

FAIL: elf/tst-cet-legacy-4
FAIL: elf/tst-cet-legacy-5a
FAIL: elf/tst-cet-legacy-6a

which are caused by

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113039

These tests use -fcf-protection -fcf-protection=branch and assume that
-fcf-protection=branch will override -fcf-protection.  But this GCC 14
commit:

https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=1c6231c05bdcca

changed the -fcf-protection behavior such that

-fcf-protection -fcf-protection=branch

is treated the same as

-fcf-protection

Use

-fcf-protection -fcf-protection=none -fcf-protection=branch

as the workaround.  This fixes BZ #31187.

Tested with GCC 13 and GCC 14 on Intel Tiger Lake.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-01-01 15:53:52 -08:00
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
H.J. Lu
cf9481724b x86/cet: Run some CET tests with shadow stack
When CET is disabled by default, run some CET tests with shadow stack
enabled using

$ export GLIBC_TUNABLES=glibc.cpu.hwcaps=SHSTK
2024-01-01 05:22:48 -08:00