without explicit alignment directives, whether they end up at the
necessary alignment depends on linker/linking conditions. initially
reported as mold issue 1255.
this interface was added as the outcome of Austin Group tracker issue
697. no error is specified for unsupported flags, which is probably an
oversight. for now, EOPNOTSUPP is used so as not to overload EINVAL.
the bits file is retained, but as a single generic version, to allow
for the unlikely future possibility of letting a new arch define
something differently.
previously, only a few archs defined it here. this change makes the
presence consistent across all archs, and reduces the amount of header
duplication (and potential for future inconsistency) between archs.
this change is purely to document that they are the same in
preparation to remove the arch-specific headers for these archs and
replace them with a generic version that matches riscv32 and can be
shared by these and all future archs.
commit f47a8cdd25 introduced an
alternate mechanism for access to runtime page size for compatibility
with early stages of dynamic linking, but because pthread_impl.h
indirectly includes libc.h, the condition #ifndef PAGE_SIZE was never
satisfied.
rather than depend on order of inclusion, use the (baseline POSIX)
macro PAGESIZE, not the (XSI) macro PAGE_SIZE, to determine whether
page size is dynamic. our internal libc.h only provides a dynamic
definition for PAGE_SIZE, not for PAGESIZE.
the %s conversion is added as the outcome of Austin Group tracker
issue 169 and its unspecified behavior is clarified as the outcome of
issue 1727.
the %F, %g, %G, %u, %V, %z, and %Z conversions are added as the
outcome of Austin Group tracker issue 879 for alignment with strftime
and the behaviors of %u, %z, and %Z are defined as the outcome of
issue 1727.
at this time, the conversions with unspecified effects on struct tm
are all left as parse-only no-ops. this may be changed at a later
time, particularly for %s, if there is reasonable cross-implementation
consensus outside the standards process on what the behavior should
be.
once the remaining value is less than 10, the modulo operation to
produce the final digit and division to prepare for next loop
iteration can be dropped. this may be a meaningful performance
distinction when formatting low-magnitude numbers in bulk, and should
never hurt.
based on patch by Viktor Reznov.
historically linux limited the number of supplementary groups a
process could be in to 32, but this limit was raised to 65536 in linux
2.6.4. proposals to support the new limit, change NGROUPS_MAX, or make
it dynamic have been stalled due to the impact it would have on
initgroups where the groups array exists in automatic storage.
the changes here decouple initgroups from the value of NGROUPS_MAX and
allow it to fall back to allocating a buffer in the case where
getgrouplist indicates the user has more supplementary groups than
could be reported in the buffer. getgrouplist already involves
allocation, so this does not pull in any new link dependency.
likewise, getgrouplist is already using the public malloc (vs internal
libc one), so initgroups does the same. if this turns out not to be
the best choice, both can be changed together later.
the initial buffer size is left at 32, but now as the literal value,
so that any potential future change to NGROUPS_MAX will not affect
initgroups.
commit cfa0a54c08 attempted to fix
rounding on archs where long double is not 80-bit (where LDBL_MANT_DIG
is not zero mod four), but failed to address the edge case where
rounding was skipped because LDBL_MANT_DIG/4 rounded down in the
comparison against the requested precision.
the rounding logic based on hex digit count is difficult to understand
and not well-motivated, so rather than try to fix it, replace it with
an explicit calculation in terms of number of bits to be kept, without
any truncating division operations. based on patch by Peter Ammon, but
with scalbn to apply the rounding exponent since the value will not
generally fit in any integer type. scalbn is used instead of scalbnl
to avoid pulling in the latter unnecessarily, since the value is an
exact power of two whose exponent range is bounded by LDBL_MANT_DIG, a
small integer.
The principal expressions defining acosh and acos are such that
acosh(z) = ±i acos(z)
where the + is only true on the Im(z)>0 half of the complex plane
(and partly on Im(z)==0 depending on number representation).
fix the comment without expanding on the details.
POSIX requires pwrite to honor the explicit file offset where the
write should take place even if the file was opened as O_APPEND.
however, linux historically defined the pwrite syscall family as
honoring O_APPEND. this cannot be changed on the kernel side due to
stability policy, but the addition of the pwritev2 syscall with a
flags argument opened the door to fixing it, and linux commit
73fa7547c70b32cc69685f79be31135797734eb6 adds the RWF_NOAPPEND flag
that lets us request a write honoring the file offset argument.
this patch changes the pwrite function to first attempt using the
pwritev2 syscall with RWF_NOAPPEND, falling back to using the old
pwrite syscall only after checking that O_APPEND is not set for the
open file. if O_APPEND is set, the operation fails with EOPNOTSUPP,
reflecting that the kernel does not support the correct behavior. this
is an extended error case needed to avoid the wrong behavior that
happened before (writing the data at the wrong location), and is
aligned with the spirit of the POSIX requirement that "An attempt to
perform a pwrite() on a file that is incapable of seeking shall result
in an error."
since the pwritev2 syscall interprets the offset of -1 as a request to
write at the current file offset, it is mapped to a different negative
value that will produce the expected error.
pwritev, though not governed by POSIX at this time, is adjusted to
match pwrite in honoring the offset.
added in linux kernel commit 73fa7547c70b32cc69685f79be31135797734eb6.
this is added now as a prerequisite for fixing pwrite/pwritev behavior
for O_APPEND files.
the jis0208 table we use is only 84x94 in size, but the shift_jis
encoding supports a 94x94 grid. attempts to convert sequences outside
of the supported zone resulted in out-of-bounds table reads,
misinterpreting adjacent rodata as part of the character table and
thereby converting these sequences to unexpected characters.
this is not needed, but may act as a hint to the compiler, and also
serves to suppress unused function warnings if enabled (on by default
since commit 86ac0f7947).
this is how it's defined in the cp936 document referenced by the IANA
charset registry as defining GBK, and of the mappings defined there,
was the only one missing.
it is not accepted for GB18030, as GB18030 is a UTF and has its own
unique mapping for the euro symbol.
- add mount_setattr from linux v5.12
- add epoll_pwait2 from linux v5.11
- add process_madvise from linux v5.10
- add __NR_faccessat2 from linux v5.8
- add pidfd_getfd and openat2 syscall numbers from linux v5.6
- add clone3 syscall number from linux v5.3
- add process_mrelease from linux v5.15
- add futex_waitv from linux v5.16
- add set_mempolicy_home_node from linux v5.17
- add cachestat from linux v6.4
- add __NR_fchmodat2 from linux v6.6
despite riscv32 being natively time64, the IPC_TIME64 bit (0x100) is
set in IPC_STAT and derived command macros, differentiating their
values from the raw command values used to interface with the kernel.
this reflects that the kernel ipc structure types are not natively
time64, but have broken-down hi/lo fields that cannot be used in-place
and require translation, and that the userspace struct types differ
from the kernel types (relevant to things like strace).
These are mostly copied from riscv64. _Addr and _Reg had to become int
to match compiler-controlled parts of the ABI (result type of sizeof,
etc.). There is no kernel stat struct; the userspace stat matches
glibc in the sizes and offsets of all fields (including glibc's
__dev_t __pad1). The jump buffer is 12 words larger to account for 12
saved double-precision floats; additionally it should be 64-bit
aligned to save doubles.
The syscall list was significantly revised by deleting all time32 and
pre-statx syscalls, and renaming several syscalls that have different
names depending on __BITS_PER_LONG, notably mmap2 and _llseek.
futex was added as an alias to futex_time64 since it is widely used by
software which does not pass time arguments.
__res_send returns the full answer length even if it didn't fit the
buffer, but __dns_parse expects the length of the filled part of the
buffer.
This is analogous to commit 77327ed064,
which fixed the only other __dns_parse call site.
A child process created by posix_spawn reports errors to its parent via
a pipe, retrying infinitely on any write error to prevent falsely
reporting success. If the (original) parent dies before write is
attempted, there is nobody to report to, but the child will remain
stuck in the write loop forever if SIGPIPE is blocked or ignored.
Fix this by not retrying write if it fails with EPIPE.
user_regs_struct and user_fp_struct were missing from the initial
commit of the port.
the union type for elf_fpreg_t and the new value of ELF_NFPREG are
made consistent with glibc.
originally, compilers did not provide these macros and we had to
provide them ourselves. this meant we were redefining them, which was
technically invalid unless the token sequence of the original
definition matched exactly.
the original patch proposed by Jules Maselbas to fix this made the
definitions conditional on them not already being defined; however I
suggested using #undef to avoid any possibly-wrong definitions already
in place and ensure that the definitions are 1. the version adopted as
commit 8b70486807 made this change.
unfortunately, gcc is loud about not liking #undef of any __STDC_*
macro name, and while warnings are suppressed in the system include
path, there is apparently no way to suppress this warning if the
system include dir has also been provided via -I.
while normally we don't go out of our way to satisfy warnings over
style in the public headers, in this case, it seems to be a matter of
disagreement over contract of which part of "the implementation" is
entitled to define or undefine macros belonging to the implementation,
and it's quite reasonable to conclude that the compiler may reject
attempts to undefine them.
this commit reverts to the originally-submitted version of the patch
making the definitions conditional.
this code dates back to the original commit of the sh port, with no
real clue as to how the bug was introduced. it looks like it was
written to assume the return address was pushed to the stack like on
x86, rather than arriving in the pr special register.
commit 0dc4824479 worked around for lack
of flags argument in syscall for fchmodat.
linux 6.6 introduced a new syscall, SYS_fchmodat2, fixing this
deficiency. use it if any flags are passed, and fallback to the old
strategy on ENOSYS. continue using the old syscall when there are no
flags. this is the exact same strategy used when SYS_faccessat2 was used
to implement faccessat with flags.
the linux fchmodat syscall lacks a flag argument that is necessary to
implement the posix api, see
linux commit 09da082b07bbae1c11d9560c8502800039aebcea
fs: Add fchmodat2()
linux commit 78252deb023cf0879256fcfbafe37022c390762b
arch: Register fchmodat2, usually as syscall 452
mojyack