H.J. Lu [Thu, 21 Dec 2023 03:42:12 +0000 (19:42 -0800)]
x86-64: Fix the tcb field load for x32 [BZ #31185]
_dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic access the thread pointer
via the tcb field in TCB:
_dl_tlsdesc_undefweak:
_CET_ENDBR
movq 8(%rax), %rax
subq %fs:0, %rax
ret
_dl_tlsdesc_dynamic:
...
subq %fs:0, %rax
movq -8(%rsp), %rdi
ret
Since the tcb field in TCB is a pointer, %fs:0 is a 32-bit location,
not 64-bit. It should use "sub %fs:0, %RAX_LP" instead. Since
_dl_tlsdesc_undefweak returns ptrdiff_t and _dl_make_tlsdesc_dynamic
returns void *, RAX_LP is appropriate here for x32 and x86-64. This
fixes BZ #31185.
H.J. Lu [Thu, 21 Dec 2023 00:31:43 +0000 (16:31 -0800)]
x86-64: Fix the dtv field load for x32 [BZ #31184]
On x32, I got
FAIL: elf/tst-tlsgap
$ gdb elf/tst-tlsgap
...
open tst-tlsgap-mod1.so
Thread 2 "tst-tlsgap" received signal SIGSEGV, Segmentation fault.
[Switching to LWP 2268754]
_dl_tlsdesc_dynamic () at ../sysdeps/x86_64/dl-tlsdesc.S:108
108 movq (%rsi), %rax
(gdb) p/x $rsi
$4 = 0xf7dbf9005655fb18
(gdb)
This is caused by
_dl_tlsdesc_dynamic:
_CET_ENDBR
/* Preserve call-clobbered registers that we modify.
We need two scratch regs anyway. */
movq %rsi, -16(%rsp)
movq %fs:DTV_OFFSET, %rsi
Since the dtv field in TCB is a pointer, %fs:DTV_OFFSET is a 32-bit
location, not 64-bit. Load the dtv field to RSI_LP instead of rsi.
This fixes BZ #31184.
H.J. Lu [Fri, 28 Jul 2023 21:06:01 +0000 (14:06 -0700)]
x86/cet: Don't disable CET if not single threaded
In permissive mode, don't disable IBT nor SHSTK when dlopening a legacy
shared library if not single threaded since IBT and SHSTK may be still
enabled in other threads. Other threads with IBT or SHSTK enabled will
crash when calling functions in the legacy shared library. Instead, an
error will be issued.
H.J. Lu [Fri, 24 Mar 2023 20:20:06 +0000 (13:20 -0700)]
x86: Modularize sysdeps/x86/dl-cet.c
Improve readability and make maintenance easier for dl-feature.c by
modularizing sysdeps/x86/dl-cet.c:
1. Support processors with:
a. Only IBT. Or
b. Only SHSTK. Or
c. Both IBT and SHSTK.
2. Lock CET features only if IBT or SHSTK are enabled and are not
enabled permissively.
Szabolcs Nagy [Wed, 29 Nov 2023 11:31:37 +0000 (11:31 +0000)]
elf: Add TLS modid reuse test for bug 29039
This is a minimal regression test for bug 29039 which only affects
targets with TLSDESC and a reproducer requires that
1) Have modid gaps (closed modules) with old generation.
2) Update a DTV to a newer generation (needs a newer dlopen).
3) But do not update the closed gap entry in that DTV.
4) Reuse the modid gap for a new module (another dlopen).
5) Use dynamic TLSDESC in that new module with old generation (bug).
6) Access TLS via this TLSDESC and the now outdated DTV.
However step (3) in practice rarely happens: during DTV update the
entries for closed modids are initialized to "unallocated" and then
dynamic TLSDESC calls __tls_get_addr independently of its generation.
The only exception to this is DTV setup at thread creation (gaps are
initialized to NULL instead of unallocated) or DTV resize where the
gap entries are outside the previous DTV array (again NULL instead
of unallocated, and this requires loading > DTV_SURPLUS modules).
So the bug can only cause NULL (+ offset) dereference, not use after
free. And the easiest way to get (3) is via thread creation.
Note that step (5) requires that the newly loaded module has larger
TLS than the remaining optional static TLS. And for (6) there cannot
be other TLS access or dlopen in the thread that updates the DTV.
Joe Ramsay [Tue, 19 Dec 2023 16:44:01 +0000 (16:44 +0000)]
aarch64: Add half-width versions of AdvSIMD f32 libmvec routines
Compilers may emit calls to 'half-width' routines (two-lane
single-precision variants). These have been added in the form of
wrappers around the full-width versions, where the low half of the
vector is simply duplicated. This will perform poorly when one lane
triggers the special-case handler, as there will be a redundant call
to the scalar version, however this is expected to be rare at Ofast.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Stefan Liebler [Wed, 13 Dec 2023 11:44:50 +0000 (12:44 +0100)]
Fix elf/tst-env-setuid[-static] if test needs to be rerun.
If /tmp is mounted nosuid and make xcheck is run,
then tst-env-setuid fails UNSUPPORTED with "SGID failed: GID and EGID match"
and /var/tmp/tst-sonamemove-runmod1.so.profile is created.
If you then try to rerun the test with a suid mounted test-dir
(the SGID binary is created in test-dir which defaults to /tmp)
with something like that:
make tst-env-setuid-ENV="TMPDIR=..." t=elf/tst-env-setuid test
the test fails as the LD_PROFILE output file is still available
from the previous run.
Thus this patch removes the LD_PROFILE output file in parent
before spawning the SGID binary.
Even if LD_PROFILE is not supported anymore in static binaries,
use a different library and thus output file for tst-env-setuid
and tst-env-setuid-static in order to not interfere if both
tests are run in parallel.
Furthermore the checks in test_child are now more verbose. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
H.J. Lu [Tue, 19 Dec 2023 17:55:25 +0000 (09:55 -0800)]
tst-setcontext10.c: Undef _FORTIFY_SOURCE
When _FORTIFY_SOURCE is defined to 2, ____longjmp_chk is called,
instead of longjmp. ____longjmp_chk compares the relative stack
values to decide if it is called from a stack frame which called
setjmp. If not, ____longjmp_chk assumes that an alternate signal
stack is used. Since comparing the relative stack values isn't
reliable with user context, when there is no signal, ____longjmp_chk
will fail. Undefine _FORTIFY_SOURCE to avoid ____longjmp_chk in
user context test.
1. -AVX,-AVX2,-AVX512F should be used to disable AVX, AVX2 and AVX512.
2. AVX512 IFUNC functions check AVX512VL. -AVX512VL should be added
to disable these functions.
Bruno Haible [Thu, 2 Nov 2023 19:19:44 +0000 (16:19 -0300)]
hppa: Fix undefined behaviour in feclearexcept (BZ 30983)
The expression
(excepts & FE_ALL_EXCEPT) << 27
produces a signed integer overflow when 'excepts' is specified as
FE_INVALID (= 0x10), because
- excepts is of type 'int',
- FE_ALL_EXCEPT is of type 'int',
- thus (excepts & FE_ALL_EXCEPT) is (int) 0x10,
- 'int' is 32 bits wide.
The patched code produces the same instruction sequence as
previosuly.
Bruno Haible [Tue, 24 Oct 2023 11:37:16 +0000 (08:37 -0300)]
x86: Do not raises floating-point exception traps on fesetexceptflag (BZ 30990)
According to ISO C23 (7.6.4.4), fesetexcept is supposed to set
floating-point exception flags without raising a trap (unlike
feraiseexcept, which is supposed to raise a trap if feenableexcept
was called with the appropriate argument).
The flags can be set in the 387 unit or in the SSE unit. When we need
to clear a flag, we need to do so in both units, due to the way
fetestexcept is implemented.
When we need to set a flag, it is sufficient to do it in the SSE unit,
because that is guaranteed to not trap. However, on i386 CPUs that have
only a 387 unit, set the flags in the 387, as long as this cannot trap.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
i686: Do not raise exception traps on fesetexcept (BZ 30989)
According to ISO C23 (7.6.4.4), fesetexcept is supposed to set
floating-point exception flags without raising a trap (unlike
feraiseexcept, which is supposed to raise a trap if feenableexcept
was called with the appropriate argument).
The flags can be set in the 387 unit or in the SSE unit. To set
a flag, it is sufficient to do it in the SSE unit, because that is
guaranteed to not trap. However, on i386 CPUs that have only a
387 unit, set the flags in the 387, as long as this cannot trap.
powerpc: Do not raise exception traps for fesetexcept/fesetexceptflag (BZ 30988)
According to ISO C23 (7.6.4.4), fesetexcept is supposed to set
floating-point exception flags without raising a trap (unlike
feraiseexcept, which is supposed to raise a trap if feenableexcept was
called with the appropriate argument).
This is a side-effect of how we implement the GNU extension
feenableexcept, where feenableexcept/fesetenv/fesetmode/feupdateenv
might issue prctl (PR_SET_FPEXC, PR_FP_EXC_PRECISE) depending of the
argument. And on PR_FP_EXC_PRECISE, setting a floating-point exception
flag triggers a trap.
To make the both functions follow the C23, fesetexcept and
fesetexceptflag now fail if the argument may trigger a trap.
The math tests now check for an value different than 0, instead
of bail out as unsupported for EXCEPTION_SET_FORCES_TRAP.
The loader now warns for invalid and out-of-range tunable values. The
patch also fixes the parsing of size_t maximum values, where
_dl_strtoul was failing for large values close to SIZE_MAX.
Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The tunable parsing duplicates the tunable environment variable so it
null-terminates each one since it simplifies the later parsing. It has
the drawback of adding another point of failure (__minimal_malloc
failing), and the memory copy requires tuning the compiler to avoid mem
operations calls.
The parsing now tracks the tunable start and its size. The
dl-tunable-parse.h adds helper functions to help parsing, like a strcmp
that also checks for size and an iterator for suboptions that are
comma-separated (used on hwcap parsing by x86, powerpc, and s390x).
Since the environment variable is allocated on the stack by the kernel,
it is safe to keep the references to the suboptions for later parsing
of string tunables (as done by set_hwcaps by multiple architectures).
Checked on x86_64-linux-gnu, powerpc64le-linux-gnu, and
aarch64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Joseph Myers [Tue, 19 Dec 2023 16:00:11 +0000 (16:00 +0000)]
Do not build sparc32 libgcc functions into static libc
Since GCC commit f31a019d1161ec78846473da743aedf49cca8c27 "Emit
funcall external declarations only if actually used.", the glibc
testsuite has failed to build for 32-bit SPARC with GCC mainline.
/scratch/jmyers/glibc-bot/install/compilers/sparc64-linux-gnu/lib/gcc/sparc64-glibc-linux-gnu/14.0.0/../../../../sparc64-glibc-linux-gnu/bin/ld: /scratch/jmyers/glibc-bot/install/compilers/sparc64-linux-gnu/lib/gcc/sparc64-glibc-linux-gnu/14.0.0/32/libgcc.a(_divsi3.o): in function `.div':
/scratch/jmyers/glibc-bot/src/gcc/libgcc/config/sparc/lb1spc.S:138: multiple definition of `.div'; /scratch/jmyers/glibc-bot/build/glibcs/sparcv9-linux-gnu/glibc/libc.a(sdiv.o):/scratch/jmyers/glibc-bot/src/glibc/gnulib/../sysdeps/sparc/sparc32/sparcv9/sdiv.S:13: first defined here
/scratch/jmyers/glibc-bot/install/compilers/sparc64-linux-gnu/lib/gcc/sparc64-glibc-linux-gnu/14.0.0/../../../../sparc64-glibc-linux-gnu/bin/ld: disabling relaxation; it will not work with multiple definitions
collect2: error: ld returned 1 exit status
make[3]: *** [../Rules:298: /scratch/jmyers/glibc-bot/build/glibcs/sparcv9-linux-gnu/glibc/nptl/tst-cancel24-static] Error 1
I'm not sure of the exact sequence of undefined references that cause
first the glibc object file defining .div and then the libgcc object
file defining both .div and .udiv to be pulled in (which must have
been perturbed by that GCC change in a way that introduced the build
failure), but I think the failure illustrates that it's inherently
fragile for glibc to define symbols in separate object files that
libgcc defines in the same object file - and indeed for glibc to
redefine libgcc symbols at all, since the division into object files
shouldn't really be part of the interface between libgcc and libc.
These symbols appear to be in libc only for compatibility, maybe one
of the cases where they were accidentally exported from shared libc in
glibc 2.0 before the introduction of symbol versioning and so programs
started expecting shared libc to provide them. Thus, there is no need
to have them in static libc. Add this set of libgcc functions to
shared-only-routines so they are no longer provided in static libc.
(No change is made regarding .mul - dotmul source file - since unlike
the other symbols in this grouping, it doesn't actually appear to be a
libgcc symbol, at least in current GCC.)
Tested with build-many-glibcs.py for sparcv9-linux-gnu with GCC
mainline.
H.J. Lu [Wed, 22 Mar 2023 20:34:55 +0000 (13:34 -0700)]
x86/cet: Check legacy shadow stack code in .init_array section
Verify that legacy shadow stack code in .init_array section in application
and shared library, which are marked as shadow stack enabled, will trigger
segfault.
Stefan Liebler [Fri, 15 Dec 2023 08:26:40 +0000 (09:26 +0100)]
s390: Set psw addr field in getcontext and friends.
So far if the ucontext structure was obtained by getcontext and co,
the return address was stored in general purpose register 14 as
it is defined as return address in the ABI.
In contrast, the context passed to a signal handler contains the address
in psw.addr field.
If somebody e.g. wants to dump the address of the context, the origin
needs to be known.
Now this patch adjusts getcontext and friends and stores the return address
also in psw.addr field.
Note that setcontext isn't adjusted and it is not supported to pass a
ucontext structure from signal-handler to setcontext. We are not able to
restore all registers and branching to psw.addr without clobbering one
register.
Matthew Sterrett [Fri, 15 Dec 2023 20:04:05 +0000 (12:04 -0800)]
x86: Unifies 'strlen-evex' and 'strlen-evex512' implementations.
This commit uses a common implementation 'strlen-evex-base.S' for both
'strlen-evex' and 'strlen-evex512'
The motivation is to reduce the number of implementations to maintain.
This incidentally gives a small performance improvement.
All tests pass on x86.
Benchmarks were taken on SKX.
https://www.intel.com/content/www/us/en/products/sku/123613/intel-core-i97900x-xseries-processor-13-75m-cache-up-to-4-30-ghz/specifications.html
Geometric mean for strlen-evex512 over all benchmarks (N=10) was (new/old) 0.939
Geometric mean for wcslen-evex512 over all benchmarks (N=10) was (new/old) 0.965
H.J. Lu [Sat, 16 Dec 2023 16:53:12 +0000 (08:53 -0800)]
x86/cet: Don't assume that SHSTK implies IBT
Since shadow stack (SHSTK) is enabled in the Linux kernel without
enabling indirect branch tracking (IBT), don't assume that SHSTK
implies IBT. Use "CPU_FEATURE_ACTIVE (IBT)" to check if IBT is active
and "CPU_FEATURE_ACTIVE (SHSTK)" to check if SHSTK is active.
RushingAlien [Mon, 21 Aug 2023 03:55:30 +0000 (10:55 +0700)]
id_ID: Update Time Locales
Hello! I am Indonesian, was born and raised in Indonesia and still do live in
Indonesia.
This patch brings a few changes to the time locales of id_ID, which
includes :
\- Defining am_pm and time_fmpt_ampm
\- Changing time_fmt and d_t_fmt to use the 24-hour format
\- Changing first_weekday to Monday
This is a squashed version of what is previously a 5 patch set
Here are reasons and details of the changes :
Change 1 part 1
id_ID: Define `am_pm` string
Current formatting does not define am_pm string, leading to AM and PM
not being specified in 12 H time format. This change defines the string
by changing it from an empty string to "AM";"PM".
output of `date +%r`:
before commit: 01:23
after commit: 01:23 PM
Change 1 part 2
id_ID: Define time_fmt_ampm, change from an empty string
Currently, time_fmpt_ampm is set to an empty string, causing some
programs to not be able to display time in the 12-hour format, for
example, glib: https://gitlab.gnome.org/GNOME/glib/-/issues/2967.
This commit changes it from an empty string to "%I:%M:%S %p"
Change 2 part 1
id_ID: Use 24-hour format for time_fmt
Indonesian standard and formal time format uses the 24-hour format inst-
ead of the 12-hour format. This commit aims to change the id_ID locale's
time_fmt to match that accordingly.
Change 2 part 2
id_ID: Use 24-hour format for d_t_fmt.
Indonesian standard and formal time format uses the 24-hour format inst-
ead of the 12-hour format. This commit aims to change the id_ID locale's
d_t_fmt to match that accordingly.
Change 3
id_ID: Change first_weekday to monday
Indonesian calendar starts of the week with Monday, let's comply
Message-ID: <20230821035530.9075-1-rushing27alien@gmail.com>
Resolves: BZ # 30412 Reviewed-by: Mike Fabian <mfabian@redhat.com>
Amrita H S [Fri, 15 Dec 2023 16:48:17 +0000 (11:48 -0500)]
powerpc: Fix performance issues of strcmp power10
Current implementation of strcmp for power10 has
performance regression for multiple small sizes
and alignment combination.
Most of these performance issues are fixed by this
patch. The compare loop is unrolled and page crosses
of unrolled loop is handled.
Thanks to Paul E. Murphy for helping in fixing the
performance issues.
Signed-off-by: Amrita H S <amritahs@linux.vnet.ibm.com> Co-Authored-By: Paul E. Murphy <murphyp@linux.ibm.com> Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
MAHESH BODAPATI [Tue, 12 Dec 2023 14:52:45 +0000 (08:52 -0600)]
powerpc : Add optimized memchr for POWER10
Optimized memchr for POWER10 based on existing rawmemchr and strlen.
Reordering instructions and loop unrolling helped in getting better performance. Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
Bruno Haible [Tue, 12 Dec 2023 08:45:16 +0000 (09:45 +0100)]
intl: Treat C.UTF-8 locale like C locale, part 2 (BZ# 16621)
The previous commit was incomplete: gettext() still returns a translation
if the file /usr/share/locale/C/LC_MESSAGES/<domain>.mo exists. This patch
prohibits the translation also in this case.
* gettext-runtime/intl/dcigettext.c (DCIGETTEXT): Treat C.<encoding> locale
like the C locale.
Ludwig Rydberg [Mon, 11 Dec 2023 12:50:41 +0000 (13:50 +0100)]
resolv: Fix a few unaligned accesses to fields in HEADER
After refactoring the alloca usage in 40c0add7d4 ("resolve: Remove
__res_context_query alloca usage") a few unaligned accesses to HEADER
fields surfaced. These unaligned accesses led to problems when running
the resolv test suite on sparc32-linux (leon) as many tests failed due to
SIGBUS crashes.
The issue(s) occured during T_QUERY_A_AND_AAAA queries as the second query
now can start on an unaligned address (previously it was explicitly aligned).
With this patch the unaligned accesses are now fixed by using the
UHEADER instead to ensure the fields are accessed with byte
loads/stores.
The patch has been verfied by running the resolv test suite on sparc32
and x86_64.
Signed-off-by: Ludwig Rydberg <ludwig.rydberg@gaisler.com> Signed-off-by: Andreas Larsson <andreas@gaisler.com> Reviewed-by: Florian Weimer <fweimer@redhat.com>
H.J. Lu [Thu, 7 Dec 2023 21:05:39 +0000 (13:05 -0800)]
x86: Check PT_GNU_PROPERTY early
The PT_GNU_PROPERTY segment is scanned before PT_NOTE. For binaries
with the PT_GNU_PROPERTY segment, we can check it to avoid scan of
the PT_NOTE segment. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Florian Weimer [Fri, 8 Dec 2023 08:51:34 +0000 (09:51 +0100)]
elf: Initialize GLRO(dl_lazy) before relocating libc in dynamic startup
GLRO(dl_lazy) is used to set the parameters for the early
_dl_relocate_object call, so the consider_profiling setting has to
be applied before the call.
One of the requirements to becoming a CVE Numbering Authority (CNA) is
to publish advisories. Do this by maintaining a file for each CVE fixed
in the advisories directory in the source tree. Links to the advisories
can then be shared as:
The file format at the moment is rudimentary and derives from the git
commit format, i.e. a subject line and a potentially multi-paragraph
description and then tags to describe some meta information. This is a
loose format at the moment and could change as we evolve this.
Also add a script process-fixed-cves.sh that processes these advisories
and generates a list to add to NEWS at release time.
Amrita H S [Wed, 6 Dec 2023 16:43:11 +0000 (11:43 -0500)]
powerpc: Optimized strcmp for power10
This patch is based on __strcmp_power9 and __strlen_power10.
Improvements from __strcmp_power9:
1. Uses new POWER10 instructions
- This code uses lxvp to decrease contention on load
by loading 32 bytes per instruction.
2. Performance implication
- This version has around 30% better performance on average.
- Performance regression is seen for a specific combination
of sizes and alignments. Some of them is observed without
changes also, while rest may be induced by the patch.
Signed-off-by: Amrita H S <amritahs@linux.vnet.ibm.com> Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
It splits between process_envvars_secure and process_envvars_default,
with the former used to process arguments for __libc_enable_secure.
It does not have any semantic change, just simplify the code so there
is no need to handle __libc_enable_secure on each len switch.
Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Loader already ignores LD_DEBUG, LD_DEBUG_OUTPUT, and
LD_TRACE_LOADED_OBJECTS. Both LD_WARN and LD_VERBOSE are similar to
LD_DEBUG, in the sense they enable additional checks and debug
information, so it makes sense to disable them.
Also add both LD_VERBOSE and LD_WARN on filtered environment variables
for setuid binaries.
Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Call the document a "Security Policy" to disambiguate it from the
security *process* documented in the security page. Also, point to the
security page for bug reporting and CVE assignment.
Andreas Schwab [Thu, 23 Nov 2023 17:23:46 +0000 (18:23 +0100)]
aarch64: correct CFI in rawmemchr (bug 31113)
The .cfi_return_column directive changes the return column for the whole
FDE range. But the actual intent is to tell the unwinder that the value
in x30 (lr) now resides in x15 after the move, and that is expressed by
the .cfi_register directive.
Joe Ramsay [Fri, 1 Dec 2023 09:49:45 +0000 (09:49 +0000)]
math: Add new exp10 implementation
New implementation is based on the existing exp/exp2, with different
reduction constants and polynomial. Worst-case error in round-to-
nearest is 0.513 ULP.
The exp/exp2 shared table is reused for exp10 - .rodata size of
e_exp_data increases by 64 bytes.
As for exp/exp2, targets with single-instruction rounding/conversion
intrinsics can use them by toggling TOINT_INTRINSICS=1 and adding the
necessary code to their math_private.h.
Improvements on Neoverse V1 compared to current GLIBC master:
exp10 thruput: 3.3x in [-0x1.439b746e36b52p+8 0x1.34413509f79ffp+8]
exp10 latency: 1.8x in [-0x1.439b746e36b52p+8 0x1.34413509f79ffp+8]
Tested on:
aarch64-linux-gnu (TOINT_INTRINSICS, fma contraction) and
x86_64-linux-gnu (!TOINT_INTRINSICS, no fma contraction)
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Flavio Cruz [Fri, 24 Nov 2023 21:30:38 +0000 (16:30 -0500)]
Update code to handle the new ABI for sending inlined port rights.
For i686, this change is no op but for x86_64 it forces all inlined port
rights to be 8 bytes long.
Message-ID: <20231124213041.952886-2-flaviocruz@gmail.com>
It is not strictly required by the POSIX, since O_PATH is a Linux
extension, but it is QoI to fail early instead of at readdir. Also
the check is free, since fdopendir already checks if the file
descriptor is opened for read.
Stefan Liebler [Tue, 21 Nov 2023 12:33:03 +0000 (13:33 +0100)]
Avoid padding in _init and _fini. [BZ #31042]
The linker just concatenates the .init and .fini sections which
results in the complete _init and _fini functions. If needed the
linker adds padding bytes due to an alignment. GNU ld is adding
NOPs, which is fine. But e.g. mold is adding traps which results
in broken _init and _fini functions.
Thus this patch removes the alignment in .init and .fini sections
in crtn.S files.
We keep the 4 byte function alignment in crti.S files. As the
assembler now also outputs the start of _init and _fini functions
as multiples of 4 byte, it perhaps has to fill it. Although GNU as
is using NOPs here, to be sure, we just keep the alignment with
0x07 (=NOPs) at the end of crti.S.
In order to avoid an obvious NOP slide in _fini, this patch also
uses an lg instead of lgr instruction. Then the emitted instructions
needs a multiple of 4 bytes.
malloc: Improve MAP_HUGETLB with glibc.malloc.hugetlb=2
Even for explicit large page support, allocation might use mmap without
the hugepage bit set if the requested size is smaller than
mmap_threshold. For this case where mmap is issued, MAP_HUGETLB is set
iff the allocation size is larger than the used large page.
To force such allocations to use large pages, also tune the mmap_threhold
(if it is not explicit set by a tunable). This forces allocation to
follow the sbrk path, which will fall back to mmap (which will try large
pages before galling back to default mmap).
Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com> Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
elf: Add a way to check if tunable is set (BZ 27069)
The patch adds two new macros, TUNABLE_GET_DEFAULT and TUNABLE_IS_INITIALIZED,
here the former get the default value with a signature similar to
TUNABLE_GET, while the later returns whether the tunable was set by
the environment variable.
Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com> Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Noah Goldstein [Wed, 1 Nov 2023 20:30:26 +0000 (15:30 -0500)]
x86: Only align destination to 1x VEC_SIZE in memset 4x loop
Current code aligns to 2x VEC_SIZE. Aligning to 2x has no affect on
performance other than potentially resulting in an additional
iteration of the loop.
1x maintains aligned stores (the only reason to align in this case)
and doesn't incur any unnecessary loop iterations. Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
_dl_assign_tls_modid() assigns a slotinfo entry for a new module, but
does *not* do anything to the generation counter. The first time this
happens, the generation is zero and map_generation() returns the current
generation to be used during relocation processing. However, if
a slotinfo entry is later reused, it will already have a generation
assigned. If this generation has fallen behind the current global max
generation, then this causes an obsolete generation to be assigned
during relocation processing, as map_generation() returns this
generation if nonzero. _dl_add_to_slotinfo() eventually resets the
generation, but by then it is too late. This causes DTV updates to be
skipped, leading to NULL or broken TLS slot pointers and segfaults.
Fix this by resetting the generation to zero in _dl_assign_tls_modid(),
so it behaves the same as the first time a slot is assigned.
_dl_add_to_slotinfo() will still assign the correct static generation
later during module load, but relocation processing will no longer use
an obsolete generation.
Note that slotinfo entry (aka modid) reuse typically happens after a
dlclose and only TLS access via dynamic tlsdesc is affected. Because
tlsdesc is optimized to use the optional part of static TLS, dynamic
tlsdesc can be avoided by increasing the glibc.rtld.optional_static_tls
tunable to a large enough value, or by LD_PRELOAD-ing the affected
modules.
Fixes bug 29039.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Tobias Klauser [Tue, 28 Nov 2023 11:06:43 +0000 (12:06 +0100)]
Add TCP_MD5SIG_FLAG_IFINDEX from Linux 5.6 to netinet/tcp.h.
This patch adds the TCP_MD5SIG_FLAG_IFINDEX constant from Linux 5.6 to
sysdeps/gnu/netinet/tcp.h and updates struct tcp_md5sig accordingly to
contain the device index.
Joseph Myers [Thu, 23 Nov 2023 19:01:32 +0000 (19:01 +0000)]
Remove __access_noerrno
A recent commit, apparently commit 6c6fce572fb8f583f14d898e54fd7d25ae91cf56 "elf: Remove /etc/suid-debug
support", resulted in localplt failures for i686-gnu and x86_64-gnu:
After that commit, __access_noerrno is actually no longer used at all.
So rather than just removing the localplt expectation for that symbol
for Hurd, completely remove all definitions of and references to that
symbol.
Tested for x86_64, and with build-many-glibcs.py for i686-gnu and
x86_64-gnu.
This restore the 2.33 semantic for arena_get2. It was changed by 11a02b035b46 to avoid arena_get2 call malloc (back when __get_nproc
was refactored to use an scratch_buffer - 903bc7dcc2acafc). The
__get_nproc was refactored over then and now it also avoid to call
malloc.
The 11a02b035b46 did not take in consideration any performance
implication, which should have been discussed properly. The
__get_nprocs_sched is still used as a fallback mechanism if procfs
and sysfs is not acessible.
Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
Joe Ramsay [Tue, 21 Nov 2023 14:39:39 +0000 (14:39 +0000)]
aarch64: Fix libmvec benchmarks
These were broken by the new atan2 functions, as they were only
set up for univariate functions. Arity is now detected from the
input file - this revealed a mistake that the double-precision
inputs were being used for both single- and double-precision
routines, which is now remedied.
Florian Weimer [Wed, 22 Nov 2023 07:38:33 +0000 (08:38 +0100)]
posix: Revert the removal of the crypt prototype from <unistd.h>
Many applications still rely on this prototype. Rebuilds without
this prototype result in an implicit function declaration, which can
introduce security vulnerabilities due to 32-bit pointer truncation.
The _dl_non_dynamic_init does not parse LD_PROFILE, which does not
enable profile for dlopen objects. Since dlopen is deprecated for
static objects, it is better to remove the support.
It also allows to trim down libc.a of profile support.
Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Loader does not ignore LD_PROFILE in secure-execution mode (different
than man-page states [1]), rather it uses a different path
(/var/profile) and ignore LD_PROFILE_OUTPUT.
Allowing secure-execution profiling is already a non good security
boundary, since it enables different code paths and extra OS access by
the process. But by ignoring LD_PROFILE_OUTPUT, the resulting profile
file might also be acceded in a racy manner since the file name does not
use any process-specific information (such as pid, timing, etc.).
Another side-effect is it forces lazy binding even on libraries that
might be with DF_BIND_NOW.
Using the memcmp symbol directly allows the compile to inline the
memcmp calls (especially because _dl_tunable_set_hwcaps uses constants
values), generating better code.
Checked with tst-tunables on s390x-linux-gnu (qemu system). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The dl-symbol-redir-ifunc.h redirects compiler-generated libcalls to
arch-specific memory implementations to avoid ifunc calls where it is not
yet possible. The memcmp-isa-default-impl.h aims to fix the same issue
by calling the specific memset implementation directly.
Using the memcmp symbol directly allows the compiler to inline the memset
calls (especially because _dl_tunable_set_hwcaps uses constants values),
generating better code.
Instead of ignoring ill-formatted tunable strings, first, check all the
tunable definitions are correct and then set each tunable value. It
means that partially invalid strings, like "key1=value1:key2=key2=value'
or 'key1=value':key2=value2=value2' do not enable 'key1=value1'. It
avoids possible user-defined errors in tunable definitions.
Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Tunable definitions with more than one '=' on are parsed and enabled,
and any subsequent '=' are ignored. It means that tunables in the form
'tunable=tunable=value' or 'tunable=value=value' are handled as
'tunable=value'. These inputs are likely user input errors, which
should not be accepted.
Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Some environment variables allow alteration of allocator behavior
across setuid boundaries, where a setuid program may ignore the
tunable, but its non-setuid child can read it and adjust the memory
allocator behavior accordingly.
Most library behavior tunings is limited to the current process and does
not bleed in scope; so it is unclear how pratical this misfeature is.
If behavior change across privilege boundaries is desirable, it would be
better done with a wrapper program around the non-setuid child that sets
these envvars, instead of using the setuid process as the messenger.
The patch as fixes tst-env-setuid, where it fail if any unsecvars is
set. It also adds a dynamic test, although it requires
--enable-hardcoded-path-in-tests so kernel correctly sets the setuid
bit (using the loader command directly would require to set the
setuid bit on the loader itself, which is not a usual deployment).
Co-authored-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
elf: Ignore GLIBC_TUNABLES for setuid/setgid binaries
The tunable privilege levels were a retrofit to try and keep the malloc
tunable environment variables' behavior unchanged across security
boundaries. However, CVE-2023-4911 shows how tricky can be
tunable parsing in a security-sensitive environment.
Not only parsing, but the malloc tunable essentially changes some
semantics on setuid/setgid processes. Although it is not a direct
security issue, allowing users to change setuid/setgid semantics is not
a good security practice, and requires extra code and analysis to check
if each tunable is safe to use on all security boundaries.
It also means that security opt-in features, like aarch64 MTE, would
need to be explicit enabled by an administrator with a wrapper script
or with a possible future system-wide tunable setting.
Co-authored-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: DJ Delorie <dj@redhat.com>
git://sourceware.org / glibc.git / log