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mirror of https://sourceware.org/git/glibc.git synced 2025-08-01 10:06:57 +03:00

1054 Commits

Author SHA1 Message Date
170206b641 x86: Add SFrame support for x86 architecture
The SFrame is well supported by x86 architecture since binutils 2.41.
Enable it to be used as default frame tracer.

Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
2025-07-14 10:56:36 +01:00
0ef7965e5b x86: Update tst-gnu2-tls2 tests
Update tst-gnu2-tls2 tests to set XMM0...XMM7 to all 1s in malloc to
verify that XMM registers are preserved when _dl_tlsdesc_dynamic is
called by clearing vectors with zeroed XMM registers before
_dl_tlsdesc_dynamic and using these XMM registers to clear vectors
after _dl_tlsdesc_dynamic.  This improves the BZ #31372 test.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2025-06-19 05:46:31 +08:00
5f138519eb termios: add new baud_t interface, defined to be explicitly numeric
Add an explicitly numeric interface for baudrate setting. For glibc,
this only announces what is a fair accompli, but this is a plausible
way forward for standardization, and may be possible to infill on
non-compliant systems. The POSIX committee has stated:

[https://www.austingroupbugs.net/view.php?id=1916#c7135]

	A future version of this standard is expected to add at least
	the following symbolic constants for use as values of objects
	of type speed_t: B57600, B115200, B230400, B460800, and
	B921600.

	Implementations are encouraged to propose additional
	interfaces which will make it possible to set and query a
	wider range of speeds than just those enumerated by the
	constants beginning with B. If a set of common interfaces
	emerges between several implementations, a future version of
	this standard will likely add those interfaces.

This is exactly that interface.

The use of the term "baud" is due to the need to have a term
contrasting "speed", and it is already well established as a legacy
term -- including in the names of the legacy Bxxx
constants. Futhermore, it *is* valid from the point of view that the
termios interface fundamentally emulates an RS-232 serial port as far
as the application software is concerned.

The documentation states that for the current version of glibc,
speed_t == baud_t, but explicitly declares that this may not be the
case in the future.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-06-17 09:11:38 -03:00
5cf101a85a linux: implement arbitrary and split speeds in termios
Linux has supported arbitrary speeds and split speeds in the kernel
since 2008 on all platforms except Alpha (fixed in 2020), but glibc
was never updated to match. This is further complicated by POSIX uses
of macros for the cf[gs]et[io]speed interfaces, rather than plain
numbers, as it really ought to have.

On most platforms, the glibc ABI includes the c_[io]speed fields in
struct termios, but they are incorrectly used. On MIPS and SPARC, they
are entirely missing.

For backwards compatibility, the kernel will still use the legacy
speed fields unless they are set to BOTHER, and will use the legacy
output speed as the input speed if the latter is 0 (== B0). However,
the specific encoding used is visible to user space applications,
including ones other than the one running.

- SPARC and MIPS get a new struct termios, and tc[gs]etattr() is
  versioned accordingly. However, the new struct termios is set to be
  a strict extension of the old one, which means that cf* interfaces
  other than the speed-related ones do not need versioning.
- The Bxxx constants are redefined as equivalent to their integer
  values and the legacy Bxxx constants are renamed __Bxxx.
- cf[gs]et[io]speed() and cfsetspeed() are versioned accordingly.
- tcgetattr() and cfset[io]speed() are adjusted to always keep the
  c_[io]speed fields correct (unlike earlier versions), but to
  canonicalize the representation to ALSO configure the legacy fields
  if a valid legacy representation exists.
- tcsetattr(), too, canonicalizes the representation in this way
  before passing it to the kernel, to maximize compatibility with
  older applications/tools.
- The old IBAUD0 hack is removed; it is no longer necessary since
  even the legacy c_cflag baud rate fields have had separate input
  values for a long time.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-06-17 09:11:38 -03:00
6945ce4a6f sigaction: don't sign-extend sa_flags
Before:
  rt_sigaction(SIGBUS, {sa_handler=0x55abb9960139, sa_mask=[], sa_flags=SA_RESTORER|SA_RESETHAND|SA_SIGINFO|0xffffffff00000000, sa_restorer=0x7fb1b2a82050}, NULL, 8) = 0

After:
  rt_sigaction(SIGBUS, {sa_handler=0x7f6a70dce139, sa_mask=[], sa_flags=SA_RESTORER|SA_RESETHAND|SA_SIGINFO, sa_restorer=0x7f6a70c28f60}, NULL, 8) = 0

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-06-03 10:53:12 +02:00
eaf88c1025 Update syscall lists for Linux 6.15
Linux 6.15 adds the new syscall open_tree_attr.  Update
syscall-names.list and regenerate the arch-syscall.h headers with
build-many-glibcs.py update-syscalls.

Tested with build-many-glibcs.py.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-05-29 19:21:46 +00:00
06caf53adf Implement C23 rootn.
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the rootn functions, which compute the Yth root of X for
integer Y (with a domain error if Y is 0, even if X is a NaN).  The
integer exponent has type long long int in C23; it was intmax_t in TS
18661-4, and as with other interfaces changed after their initial
appearance in the TS, I don't think we need to support the original
version of the interface.

As with pown and compoundn, I strongly encourage searching for worst
cases for ulps error for these implementations (necessarily
non-exhaustively, given the size of the input space).  I also expect a
custom implementation for a given format could be much faster as well
as more accurate, although the implementation is simpler than those
for pown and compoundn.

This completes adding to glibc those TS 18661-4 functions (ignoring
DFP) that are included in C23.  See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118592 regarding the C23
mathematical functions (not just the TS 18661-4 ones) missing built-in
functions in GCC, where such functions might usefully be added.

Tested for x86_64 and x86, and with build-many-glibcs.py.
2025-05-14 10:51:46 +00:00
ae31254432 Implement C23 compoundn
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the compoundn functions, which compute (1+X) to the
power Y for integer Y (and X at least -1).  The integer exponent has
type long long int in C23; it was intmax_t in TS 18661-4, and as with
other interfaces changed after their initial appearance in the TS, I
don't think we need to support the original version of the interface.

Note that these functions are "compoundn" with a trailing "n", *not*
"compound" (CORE-MATH has the wrong name, for example).

As with pown, I strongly encourage searching for worst cases for ulps
error for these implementations (necessarily non-exhaustively, given
the size of the input space).  I also expect a custom implementation
for a given format could be much faster as well as more accurate (I
haven't tested or benchmarked the CORE-MATH implementation for
binary32); this is one of the more complicated and less efficient
functions to implement in a type-generic way.

As with exp2m1 and exp10m1, this showed up places where the
powerpc64le IFUNC setup is not as self-contained as one might hope (in
this case, without the changes specific to powerpc64le, there were
undefined references to __GI___expf128).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2025-05-09 15:17:27 +00:00
5b132ec2b7 stdlib: Implement C2Y uabs, ulabs, ullabs and uimaxabs
C2Y adds unsigned versions of the abs functions (see C2Y draft N3467 and
proposal N3349).

Tested for x86_64.

Signed-off-by: Lenard Mollenkopf <glibc@lenardmollenkopf.de>
2025-04-08 12:51:51 +00:00
75ad83f564 Implement C23 pown
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the pown functions, which are like pow but with an
integer exponent.  That exponent has type long long int in C23; it was
intmax_t in TS 18661-4, and as with other interfaces changed after
their initial appearance in the TS, I don't think we need to support
the original version of the interface.  The test inputs are based on
the subset of test inputs for pow that use integer exponents that fit
in long long.

As the first such template implementation that saves and restores the
rounding mode internally (to avoid possible issues with directed
rounding and intermediate overflows or underflows in the wrong
rounding mode), support also needed to be added for using
SET_RESTORE_ROUND* in such template function implementations.  This
required math-type-macros-float128.h to include <fenv_private.h>, so
it can tell whether SET_RESTORE_ROUNDF128 is defined.  In turn, the
include order with <fenv_private.h> included before <math_private.h>
broke loongarch builds, showing up that
sysdeps/loongarch/math_private.h is really a fenv_private.h file
(maybe implemented internally before the consistent split of those
headers in 2018?) and needed to be renamed to fenv_private.h to avoid
errors with duplicate macro definitions if <math_private.h> is
included after <fenv_private.h>.

The underlying implementation uses __ieee754_pow functions (called
more than once in some cases, where the exponent does not fit in the
floating type).  I expect a custom implementation for a given format,
that only handles integer exponents but handles larger exponents
directly, could be faster and more accurate in some cases.

I encourage searching for worst cases for ulps error for these
implementations (necessarily non-exhaustively, given the size of the
input space).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2025-03-27 10:44:44 +00:00
e3a6e85d67 Add _FORTIFY_SOURCE support for inet_pton
Add function __inet_pton_chk which calls __chk_fail when the size of
argument dst is too small.   inet_pton is redirected to __inet_pton_chk
or __inet_pton_warn when _FORTIFY_SOURCE is > 0.

Also add tests to debug/tst-fortify.c, update the abilist with
__inet_pton_chk and mention inet_pton fortification in maint.texi.

Co-authored-by: Frédéric Bérat <fberat@redhat.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-03-24 14:43:03 -04:00
090dfa40a5 Add _FORTIFY_SOURCE support for inet_ntop
- Create the __inet_ntop_chk routine that verifies that the builtin size
of the destination buffer is at least as big as the size given by the
user.
- Redirect calls from inet_ntop to __inet_ntop_chk or __inet_ntop_warn
- Update the abilist for this new routine
- Update the manual to mention the new fortification

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-03-21 09:35:42 +01:00
409668f6e8 Implement C23 powr
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the powr functions, which are like pow, but with simpler
handling of special cases (based on exp(y*log(x)), so negative x and
0^0 are domain errors, powers of -0 are always +0 or +Inf never -0 or
-Inf, and 1^+-Inf and Inf^0 are also domain errors, while NaN^0 and
1^NaN are NaN).  The test inputs are taken from those for pow, with
appropriate adjustments (including removing all tests that would be
domain errors from those in auto-libm-test-in and adding some more
such tests in libm-test-powr.inc).

The underlying implementation uses __ieee754_pow functions after
dealing with all special cases that need to be handled differently.
It might be a little faster (avoiding a wrapper and redundant checks
for special cases) to have an underlying implementation built
separately for both pow and powr with compile-time conditionals for
special-case handling, but I expect the benefit of that would be
limited given that both functions will end up needing to use the same
logic for computing pow outside of special cases.

My understanding is that powr(negative, qNaN) should raise "invalid":
that the rule on "invalid" for an argument outside the domain of the
function takes precedence over a quiet NaN argument producing a quiet
NaN result with no exceptions raised (for rootn it's explicit that the
0th root of qNaN raises "invalid").  I've raised this on the WG14
reflector to confirm the intent.

Tested for x86_64 and x86, and with build-many-glibcs.py.
2025-03-14 15:58:11 +00:00
eea6f1e079 Update syscall lists for Linux 6.13
Linux 6.13 adds four new syscalls.  Update syscall-names.list and
regenerate the arch-syscall.h headers with build-many-glibcs.py
update-syscalls.

Tested with build-many-glibcs.py.
2025-03-12 12:51:54 +00:00
74d463c50b Linux: Add the pthread_gettid_np function (bug 27880)
Current Bionic has this function, with enhanced error checking
(the undefined case terminates the process).

Reviewed-by: Joseph Myers <josmyers@redhat.com>
2025-03-12 10:23:35 +01:00
77261698b4 Implement C23 rsqrt
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the rsqrt functions (1/sqrt(x)).  The test inputs are
taken from those for sqrt.

Tested for x86_64 and x86, and with build-many-glibcs.py.
2025-03-07 19:15:26 +00:00
e5893e6349 Remove unused dl-procinfo.h
Remove unused _dl_hwcap_string defines.  As a result many dl-procinfo.h headers
can be removed.  This also removes target specific _dl_procinfo implementations
which only printed HWCAP strings using dl_hwcap_string.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-02-28 16:55:18 +00:00
1294926da3 Rename have-mtls-descriptor to have-test-mtls-descriptor
Since have-mtls-descriptor is only used for glibc testing, rename it to
have-test-mtls-descriptor.  Also enable tst-gnu2-tls2-amx only if
$(have-test-mtls-descriptor) == gnu2.

Tested with GCC 14 and Clang 19/18/17 on x86-64.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2025-01-04 04:51:21 +08:00
2642002380 Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
0ee6e13f7f x86-64: Reorder dynamic linker list in ldd script (bug 32508)
Move the x86-64 loader first, before the i386 and x32 loaders.  In
most cases, it's the loader the script needs.  This avoids an error
message if the i386 loader does not work.

The effect of this change to the generated ldd script looks like this:

-RTLDLIST="/lib/ld-linux.so.2 /lib64/ld-linux-x86-64.so.2 /libx32/ld-linux-x32.so.2"
+RTLDLIST="/lib64/ld-linux-x86-64.so.2 /lib/ld-linux.so.2 /libx32/ld-linux-x32.so.2"

Reviewed-by: Sam James <sam@gentoo.org>
2024-12-30 13:24:36 +01:00
a2b0ff98a0 include/sys/cdefs.h: Add __attribute_optimization_barrier__
Add __attribute_optimization_barrier__ to disable inlining and cloning on a
function.  For Clang, expand it to

__attribute__ ((optnone))

Otherwise, expand it to

__attribute__ ((noinline, clone))

Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-23 06:28:55 +08:00
3374de9038 Implement C23 atan2pi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the atan2pi functions (atan2(y,x)/pi).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-12 20:57:44 +00:00
ffe79c446c Implement C23 atanpi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the atanpi functions (atan(x)/pi).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-11 21:51:49 +00:00
f962932206 Implement C23 asinpi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the asinpi functions (asin(x)/pi).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-10 20:42:20 +00:00
28d102d15c Implement C23 acospi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the acospi functions (acos(x)/pi).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-09 23:01:29 +00:00
f9e90e4b4c Implement C23 tanpi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the tanpi functions (tan(pi*x)).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-05 21:42:10 +00:00
776938e8b8 Implement C23 sinpi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the sinpi functions (sin(pi*x)).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-04 20:04:04 +00:00
0ae0af68d8 Implement C23 cospi
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the cospi functions (cos(pi*x)).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-12-04 10:20:44 +00:00
461cab1de7 linux: Add support for getrandom vDSO
Linux 6.11 has getrandom() in vDSO. It operates on a thread-local opaque
state allocated with mmap using flags specified by the vDSO.

Multiple states are allocated at once, as many as fit into a page, and
these are held in an array of available states to be doled out to each
thread upon first use, and recycled when a thread terminates. As these
states run low, more are allocated.

To make this procedure async-signal-safe, a simple guard is used in the
LSB of the opaque state address, falling back to the syscall if there's
reentrancy contention.

Also, _Fork() is handled by blocking signals on opaque state allocation
(so _Fork() always sees a consistent state even if it interrupts a
getrandom() call) and by iterating over the thread stack cache on
reclaim_stack. Each opaque state will be in the free states list
(grnd_alloc.states) or allocated to a running thread.

The cancellation is handled by always using GRND_NONBLOCK flags while
calling the vDSO, and falling back to the cancellable syscall if the
kernel returns EAGAIN (would block). Since getrandom is not defined by
POSIX and cancellation is supported as an extension, the cancellation is
handled as 'may occur' instead of 'shall occur' [1], meaning that if
vDSO does not block (the expected behavior) getrandom will not act as a
cancellation entrypoint. It avoids a pthread_testcancel call on the fast
path (different than 'shall occur' functions, like sem_wait()).

It is currently enabled for x86_64, which is available in Linux 6.11,
and aarch64, powerpc32, powerpc64, loongarch64, and s390x, which are
available in Linux 6.12.

Link: https://pubs.opengroup.org/onlinepubs/9799919799/nframe.html [1]
Co-developed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com> # x86_64
Tested-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> # x86_64, aarch64
Tested-by: Xi Ruoyao <xry111@xry111.site> # x86_64, aarch64, loongarch64
Tested-by: Stefan Liebler <stli@linux.ibm.com> # s390x
2024-11-12 14:42:12 -03:00
02de16df48 Update syscall lists for Linux 6.11
Linux 6.11 changes for syscall are:

  * fstat/newfstatat for loongarch (it should be safe to add since
    255dc1e4ed that undefine them).
  * clone3 for nios2, which only adds the entry point but defined
    __ARCH_BROKEN_SYS_CLONE3 (the syscall will always return ENOSYS).
  * uretprobe for x86_64 and x32.

Update syscall-names.list and regenerate the arch-syscall.h headers
with build-many-glibcs.py update-syscalls.

Tested with build-many-glibcs.py.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-10-10 10:27:49 -03:00
21571ca0d7 Linux: Add the sched_setattr and sched_getattr functions
And struct sched_attr.

In sysdeps/unix/sysv/linux/bits/sched.h, the hack that defines
sched_param around the inclusion of <linux/sched/types.h> is quite
ugly, but the definition of struct sched_param has already been
dropped by the kernel, so there is nothing else we can do and maintain
compatibility of <sched.h> with a wide range of kernel header
versions.  (An alternative would involve introducing a separate header
for this functionality, but this seems unnecessary.)

The existing sched_* functions that change scheduler parameters
are already incompatible with PTHREAD_PRIO_PROTECT mutexes, so
there is no harm in adding more functionality in this area.

The documentation mostly defers to the Linux manual pages.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-11 10:05:08 +02:00
89b53077d2 nptl: Fix Race conditions in pthread cancellation [BZ#12683]
The current racy approach is to enable asynchronous cancellation
before making the syscall and restore the previous cancellation
type once the syscall returns, and check if cancellation has happen
during the cancellation entrypoint.

As described in BZ#12683, this approach shows 2 problems:

  1. Cancellation can act after the syscall has returned from the
     kernel, but before userspace saves the return value.  It might
     result in a resource leak if the syscall allocated a resource or a
     side effect (partial read/write), and there is no way to program
     handle it with cancellation handlers.

  2. If a signal is handled while the thread is blocked at a cancellable
     syscall, the entire signal handler runs with asynchronous
     cancellation enabled.  This can lead to issues if the signal
     handler call functions which are async-signal-safe but not
     async-cancel-safe.

For the cancellation to work correctly, there are 5 points at which the
cancellation signal could arrive:

	[ ... )[ ... )[ syscall ]( ...
	   1      2        3    4   5

  1. Before initial testcancel, e.g. [*... testcancel)
  2. Between testcancel and syscall start, e.g. [testcancel...syscall start)
  3. While syscall is blocked and no side effects have yet taken
     place, e.g. [ syscall ]
  4. Same as 3 but with side-effects having occurred (e.g. a partial
     read or write).
  5. After syscall end e.g. (syscall end...*]

And libc wants to act on cancellation in cases 1, 2, and 3 but not
in cases 4 or 5.  For the 4 and 5 cases, the cancellation will eventually
happen in the next cancellable entrypoint without any further external
event.

The proposed solution for each case is:

  1. Do a conditional branch based on whether the thread has received
     a cancellation request;

  2. It can be caught by the signal handler determining that the saved
     program counter (from the ucontext_t) is in some address range
     beginning just before the "testcancel" and ending with the
     syscall instruction.

  3. SIGCANCEL can be caught by the signal handler and determine that
     the saved program counter (from the ucontext_t) is in the address
     range beginning just before "testcancel" and ending with the first
     uninterruptable (via a signal) syscall instruction that enters the
      kernel.

  4. In this case, except for certain syscalls that ALWAYS fail with
     EINTR even for non-interrupting signals, the kernel will reset
     the program counter to point at the syscall instruction during
     signal handling, so that the syscall is restarted when the signal
     handler returns.  So, from the signal handler's standpoint, this
     looks the same as case 2, and thus it's taken care of.

  5. For syscalls with side-effects, the kernel cannot restart the
     syscall; when it's interrupted by a signal, the kernel must cause
     the syscall to return with whatever partial result is obtained
     (e.g. partial read or write).

  6. The saved program counter points just after the syscall
     instruction, so the signal handler won't act on cancellation.
     This is similar to 4. since the program counter is past the syscall
     instruction.

So The proposed fixes are:

  1. Remove the enable_asynccancel/disable_asynccancel function usage in
     cancellable syscall definition and instead make them call a common
     symbol that will check if cancellation is enabled (__syscall_cancel
     at nptl/cancellation.c), call the arch-specific cancellable
     entry-point (__syscall_cancel_arch), and cancel the thread when
     required.

  2. Provide an arch-specific generic system call wrapper function
     that contains global markers.  These markers will be used in
     SIGCANCEL signal handler to check if the interruption has been
     called in a valid syscall and if the syscalls has side-effects.

     A reference implementation sysdeps/unix/sysv/linux/syscall_cancel.c
     is provided.  However, the markers may not be set on correct
     expected places depending on how INTERNAL_SYSCALL_NCS is
     implemented by the architecture.  It is expected that all
     architectures add an arch-specific implementation.

  3. Rewrite SIGCANCEL asynchronous handler to check for both canceling
     type and if current IP from signal handler falls between the global
     markers and act accordingly.

  4. Adjust libc code to replace LIBC_CANCEL_ASYNC/LIBC_CANCEL_RESET to
     use the appropriate cancelable syscalls.

  5. Adjust 'lowlevellock-futex.h' arch-specific implementations to
     provide cancelable futex calls.

Some architectures require specific support on syscall handling:

  * On i386 the syscall cancel bridge needs to use the old int80
    instruction because the optimized vDSO symbol the resulting PC value
    for an interrupted syscall points to an address outside the expected
    markers in __syscall_cancel_arch.  It has been discussed in LKML [1]
    on how kernel could help userland to accomplish it, but afaik
    discussion has stalled.

    Also, sysenter should not be used directly by libc since its calling
    convention is set by the kernel depending of the underlying x86 chip
    (check kernel commit 30bfa7b3488bfb1bb75c9f50a5fcac1832970c60).

  * mips o32 is the only kABI that requires 7 argument syscall, and to
    avoid add a requirement on all architectures to support it, mips
    support is added with extra internal defines.

Checked on aarch64-linux-gnu, arm-linux-gnueabihf, powerpc-linux-gnu,
powerpc64-linux-gnu, powerpc64le-linux-gnu, i686-linux-gnu, and
x86_64-linux-gnu.

[1] https://lkml.org/lkml/2016/3/8/1105
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-08-23 14:27:43 -03:00
eb0776d4e1 Update syscall lists for Linux 6.10
Linux 6.10 changes for syscall are:

  * mseal for all architectures.
  * map_shadow_stack for x32.
  * Replace sync_file_range with sync_file_range2 for csky (which
    fixes a broken sync_file_range usage).

Update syscall-names.list and regenerate the arch-syscall.h headers
with build-many-glibcs.py update-syscalls.

Tested with build-many-glibcs.py.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-07-30 08:48:51 -03:00
8344c1f551 x32/cet: Support shadow stack during startup for Linux 6.10
Use RXX_LP in RTLD_START_ENABLE_X86_FEATURES.  Support shadow stack during
startup for Linux 6.10:

commit 2883f01ec37dd8668e7222dfdb5980c86fdfe277
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Mar 15 07:04:33 2024 -0700

    x86/shstk: Enable shadow stacks for x32

    1. Add shadow stack support to x32 signal.
    2. Use the 64-bit map_shadow_stack syscall for x32.
    3. Set up shadow stack for x32.

Add the map_shadow_stack system call to <fixup-asm-unistd.h> and regenerate
arch-syscall.h.  Tested on Intel Tiger Lake with CET enabled x32.  There
are no regressions with CET enabled x86-64.  There are no changes in CET
enabled x86-64 _dl_start_user.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-07-25 00:17:21 -07:00
7ec903e028 Implement C23 exp2m1, exp10m1
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the exp2m1 and exp10m1 functions (exp2(x)-1 and
exp10(x)-1, like expm1).

As with other such functions, these use type-generic templates that
could be replaced with faster and more accurate type-specific
implementations in future.  Test inputs are copied from those for
expm1, plus some additions close to the overflow threshold (copied
from exp2 and exp10) and also some near the underflow threshold.

exp2m1 has the unusual property of having an input (M_MAX_EXP) where
whether the function overflows (under IEEE semantics) depends on the
rounding mode.  Although these could reasonably be XFAILed in the
testsuite (as we do in some cases for arguments very close to a
function's overflow threshold when an error of a few ulps in the
implementation can result in the implementation not agreeing with an
ideal one on whether overflow takes place - the testsuite isn't smart
enough to handle this automatically), since these functions aren't
required to be correctly rounding, I made the implementation check for
and handle this case specially.

The Makefile ordering expected by lint-makefiles for the new functions
is a bit peculiar, but I implemented it in this patch so that the test
passes; I don't know why log2 also needed moving in one Makefile
variable setting when it didn't in my previous patches, but the
failure showed a different place was expected for that function as
well.

The powerpc64le IFUNC setup seems not to be as self-contained as one
might hope; it shouldn't be necessary to add IFUNCs for new functions
such as these simply to get them building, but without setting up
IFUNCs for the new functions, there were undefined references to
__GI___expm1f128 (that IFUNC machinery results in no such function
being defined, but doesn't stop include/math.h from doing the
redirection resulting in the exp2m1f128 and exp10m1f128
implementations expecting to call it).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-06-17 16:31:49 +00:00
55eb99e9a9 Implement C23 log10p1
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the log10p1 functions (log10(1+x): like log1p, but for
base-10 logarithms).

This is directly analogous to the log2p1 implementation (except that
whereas log2p1 has a smaller underflow range than log1p, log10p1 has a
larger underflow range).  The test inputs are copied from those for
log1p and log2p1, plus a few more inputs in that wider underflow
range.

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-06-17 13:48:13 +00:00
bb014f50c4 Implement C23 logp1
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the logp1 functions (aliases for log1p functions - the
name is intended to be more consistent with the new log2p1 and
log10p1, where clearly it would have been very confusing to name those
functions log21p and log101p).  As aliases rather than new functions,
the content of this patch is somewhat different from those actually
adding new functions.

Tests are shared with log1p, so this patch *does* mechanically update
all affected libm-test-ulps files to expect the same errors for both
functions.

The vector versions of log1p on aarch64 and x86_64 are *not* updated
to have logp1 aliases (and thus there are no corresponding header,
tests, abilist or ulps changes for vector functions either).  It would
be reasonable for such vector aliases and corresponding changes to
other files to be made separately.  For now, the log1p tests instead
avoid testing logp1 in the vector case (a Makefile change is needed to
avoid problems with grep, used in generating the .c files for vector
function tests, matching more than one ALL_RM_TEST line in a file
testing multiple functions with the same inputs, when it assumes that
the .inc file only has a single such line).

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-06-17 13:47:09 +00:00
437c94e04b Remove the clone3 symbol from libc.a [BZ #31770]
clone3 isn't exported from glibc and is hidden in libc.so.  Fix BZ #31770
by removing clone3 alias.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-05-21 07:05:08 -07:00
79c52daf47 Implement C23 log2p1
C23 adds various <math.h> function families originally defined in TS
18661-4.  Add the log2p1 functions (log2(1+x): like log1p, but for
base-2 logarithms).

This illustrates the intended structure of implementations of all
these function families: define them initially with a type-generic
template implementation.  If someone wishes to add type-specific
implementations, it is likely such implementations can be both faster
and more accurate than the type-generic one and can then override it
for types for which they are implemented (adding benchmarks would be
desirable in such cases to demonstrate that a new implementation is
indeed faster).

The test inputs are copied from those for log1p.  Note that these
changes make gen-auto-libm-tests depend on MPFR 4.2 (or later).

The bulk of the changes are fairly generic for any such new function.
(sysdeps/powerpc/nofpu/Makefile only needs changing for those
type-generic templates that use fabs.)

Tested for x86_64 and x86, and with build-many-glibcs.py.
2024-05-20 13:41:39 +00:00
3de2f8755c Update syscall lists for Linux 6.8
Linux 6.8 adds five new syscalls.  Update syscall-names.list and
regenerate the arch-syscall.h headers with build-many-glibcs.py
update-syscalls.

Tested with build-many-glibcs.py.
2024-03-13 13:57:56 +00:00
9b7091415a x86-64: Update _dl_tlsdesc_dynamic to preserve AMX registers
_dl_tlsdesc_dynamic should also preserve AMX registers which are
caller-saved.  Add X86_XSTATE_TILECFG_ID and X86_XSTATE_TILEDATA_ID
to x86-64 TLSDESC_CALL_STATE_SAVE_MASK.  Compute the AMX state size
and save it in xsave_state_full_size which is only used by
_dl_tlsdesc_dynamic_xsave and _dl_tlsdesc_dynamic_xsavec.  This fixes
the AMX part of BZ #31372.  Tested on AMX processor.

AMX test is enabled only for compilers with the fix for

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114098

GCC 14 and GCC 11/12/13 branches have the bug fix.
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
2024-02-29 04:30:01 -08:00
e6350be7e9 sysdeps/unix/sysv/linux/x86_64/Makefile: Add the end marker
Add the end marker to tests, tests-container and modules-names.
2024-02-28 05:48:27 -08:00
6a04404521 Linux: Switch back to assembly syscall wrapper for prctl (bug 29770)
Commit ff026950e2 ("Add a C wrapper for
prctl [BZ #25896]") replaced the assembler wrapper with a C function.
However, on powerpc64le-linux-gnu, the C variadic function
implementation requires extra work in the caller to set up the
parameter save area.  Calling a function that needs a parameter save
area without one (because the prototype used indicates the function is
not variadic) corrupts the caller's stack.   The Linux manual pages
project documents prctl as a non-variadic function.  This has resulted
in various projects over the years using non-variadic prototypes,
including the sanitizer libraries in LLVm and GCC (GCC PR 113728).

This commit switches back to the assembler implementation on most
targets and only keeps the C implementation for x86-64 x32.

Also add the __prctl_time64 alias from commit
b39ffab860 ("Linux: Add time64 alias for
prctl") to sysdeps/unix/sysv/linux/syscalls.list; it was not yet
present in commit ff026950e2.

This restores the old ABI on powerpc64le-linux-gnu, thus fixing
bug 29770.

Reviewed-By: Simon Chopin <simon.chopin@canonical.com>
2024-02-17 09:17:04 +01:00
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
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
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
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
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
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
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