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>
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>
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>
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.
A recent commit, apparently commit
6c6fce572f "elf: Remove /etc/suid-debug
support", resulted in localplt failures for i686-gnu and x86_64-gnu:
Missing required PLT reference: ld.so: __access_noerrno
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
11a02b035b to avoid arena_get2 call malloc (back when __get_nproc
was refactored to use an scratch_buffer - 903bc7dcc2). The
__get_nproc was refactored over then and now it also avoid to call
malloc.
The 11a02b035b 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>
Commit 7f602256ab moved the tst-rfc3484*
tests from posix/ to nss/, but didn't correct references to point to
their new subdir when building for mach and arm. This commit fixes
that.
Tested with build-many-glibcs.sh for i686-gnu.
All the crypt related functions, cryptographic algorithms, and
make requirements are removed, with only the exception of md5
implementation which is moved to locale folder since it is
required by localedef for integrity protection (libc's
locale-reading code does not check these, but localedef does
generate them).
Besides thec code itself, both internal documentation and the
manual is also adjusted. This allows to remove both --enable-crypt
and --enable-nss-crypt configure options.
Checked with a build for all affected ABIs.
Co-authored-by: Zack Weinberg <zack@owlfolio.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Making error_t defined to enum __error_t_codes conveniently makes the
debugger print symbolic values, but in C++ int is not interoperable with
enum __error_t_codes, leading to C++ application build issues, so let's
revert error_t to int in C++.
When using jemalloc, malloc() needs to use TSD, while libpthread
initialization needs malloc(). Having ___pthread_self set early to some
static storage allows TSD to work early, thus allowing jemalloc and
libpthread to initialize together.
This incidentaly simplifies __pthread_enable/disable_asynccancel and
__pthread_self, now that ___pthread_self is always initialized.
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions. autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm). It appears to
be current in Gentoo as well.
All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
MAP_FIXED is defined to silently replace any existing mappings at the
address range being mapped over. This, however, is a dangerous, and only
rarely desired behavior.
Various Unix systems provide replacements or additions to MAP_FIXED:
* SerenityOS and Linux provide MAP_FIXED_NOREPLACE. If the address space
already contains a mapping in the requested range, Linux returns
EEXIST. SerenityOS returns ENOMEM, however that is a bug, as the
MAP_FIXED_NOREPLACE implementation is intended to be compatible with
Linux.
* FreeBSD provides the MAP_EXCL flag that has to be used in combination
with MAP_FIXED. It returns EINVAL if the requested range already
contains existing mappings. This is directly analogous to the O_EXCL
flag in the open () call.
* DragonFly BSD, NetBSD, and OpenBSD provide MAP_TRYFIXED, but with
different semantics. DragonFly BSD returns ENOMEM if the requested
range already contains existing mappings. NetBSD does not return an
error, but instead creates the mapping at a different address if the
requested range contains mappings. OpenBSD behaves the same, but also
notes that this is the default behavior even without MAP_TRYFIXED
(which is the case on the Hurd too).
Since the Hurd leans closer to the BSD side, add MAP_EXCL as the primary
API to request the behavior of not replacing existing mappings. Declare
MAP_FIXED_NOREPLACE and MAP_TRYFIXED as aliases of (MAP_FIXED|MAP_EXCL),
so any existing software that checks for either of those macros will
pick them up automatically. For compatibility with Linux, return EEXIST
if a mapping already exists.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-5-bugaevc@gmail.com>
Zero address passed to mmap () typically means the caller doesn't have
any specific preferred address. Not so if MAP_FIXED is passed: in this
case 0 means literal 0. Fix this case to pass anywhere = 0 into vm_map.
Also add some documentation.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-4-bugaevc@gmail.com>
Only call vm_deallocate when we do have the old buffer, and check for
unexpected errors.
Spotted while debugging a msgids/readdir issue on x86_64-gnu.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-3-bugaevc@gmail.com>
The rest of the heap (backed by individual pages) is already mapped RW.
Mapping these pages RWX presents a security hazard.
Also, in another branch memory gets allocated using vm_allocate, which
sets memory protection to VM_PROT_DEFAULT (which is RW). The mismatch
between protections prevents Mach from coalescing the VM map entries.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-2-bugaevc@gmail.com>
Instead of trying to allocate a thread stack at a specific address,
looping over the address space, just set the ANYWHERE flag in
vm_allocate (). The previous behavior:
- defeats ASLR (for Mach versions that support ASLR),
- is particularly slow if the lower 4 GB of the address space are mapped
inaccessible, as we're planning to do on 64-bit Hurd,
- is just silly.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-1-bugaevc@gmail.com>
This follows 1d44530a5b ("string: strerror must not return NULL (bug 30555)"):
«
For strerror, this fixes commit 28aff04781 ("string:
Implement strerror in terms of strerror_l"). This commit avoids
returning NULL for strerror_l as well, although POSIX allows this
behavior for strerror_l.
»
These functions are about to be added to POSIX, under Austin Group
issue 986.
The fortified strlcat implementation does not raise SIGABRT if the
destination buffer does not contain a null terminator, it just
inherits the non-failing regular strlcat behavior.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Since the area of the user's stack we use for the registers dump (and
otherwise as __sigreturn2's stack) can and does overlap the sigcontext,
we have to be very careful about the order of loads and stores that we
do. In particular we have to load sc_reply_port before we start
clobbering the sigcontext.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
