Rich Felker [Thu, 14 Jun 2018 18:26:30 +0000 (14:26 -0400)]
add m68k port
three ABIs are supported: the default with 68881 80-bit fpu format and
results returned in floating point registers, softfloat-only with the
same format, and coldfire fpu with IEEE single/double only. only the
first is tested at all, and only under qemu which has fpu emulation
bugs.
basic functionality smoke tests have been performed for the most
common arch-specific breakage via libc-test and qemu user-level
emulation. some sysvipc failures remain, but are shared with other big
endian archs and will be fixed separately.
Rich Felker [Thu, 14 Jun 2018 15:00:58 +0000 (11:00 -0400)]
add support for m68k 80-bit long double variant
since x86 and m68k are the only archs with 80-bit long double and each
has mandatory endianness, select the variant via endianness.
differences are minor: apparently just byte order and representation
of infinities. the m68k format is not well-documented anywhere I could
find, so if other differences are found they may require additional
changes later.
Szabolcs Nagy [Fri, 1 Jun 2018 23:52:01 +0000 (01:52 +0200)]
fix TLS layout of TLS variant I when there is a gap above TP
In TLS variant I the TLS is above TP (or above a fixed offset from TP)
but on some targets there is a reserved gap above TP before TLS starts.
This matters for the local-exec tls access model when the offsets of
TLS variables from the TP are hard coded by the linker into the
executable, so the libc must compute these offsets the same way as the
linker. The tls offset of the main module has to be
alignup(GAP_ABOVE_TP, main_tls_align).
If there is no TLS in the main module then the gap can be ignored
since musl does not use it and the tls access models of shared
libraries are not affected.
The previous setup only worked if (tls_align & -GAP_ABOVE_TP) == 0
(i.e. TLS did not require large alignment) because the gap was
treated as a fixed offset from TP. Now the TP points at the end
of the pthread struct (which is aligned) and there is a gap above
it (which may also need alignment).
The fix required changing TP_ADJ and __pthread_self on affected
targets (aarch64, arm and sh) and in the tlsdesc asm the offset to
access the dtv changed too.
Rich Felker [Sat, 2 Jun 2018 02:05:48 +0000 (22:05 -0400)]
fix output size handling for multi-unicode-char big5-hkscs characters
since this iconv implementation's output is stateless, it's necessary
to know before writing anything to the output buffer whether the
conversion of the current input character will fit.
previously we used a hard-coded table of the output size needed for
each supported output encoding, but failed to update the table when
adding support for conversion to jis-based encodings and again when
adding separate encoding identifiers for implicit-endianness utf-16/32
and ucs-2/4 variants, resulting in out-of-bound table reads and
incorrect size checks. no buffer overflow was possible, but the
affected characters could be converted incorrectly, and iconv could
potentially produce an incorrect return value as a result.
remove the hard-coded table, and instead perform the recursive iconv
conversion to a temporary buffer, measuring the output size and
transferring it to the actual output buffer only if the whole
converted result fits.
Rich Felker [Sat, 2 Jun 2018 01:50:17 +0000 (21:50 -0400)]
fix iconv mapping of big5-hkscs characters that map to two unicode chars
this case is handled with a recursive call to iconv using a
specially-constructed conversion descriptor. the constant 0 was used
as the offset for utf-8, since utf-8 appears first in the charmaps
table, but the offset used needs to point into the charmap entry, past
the name/aliases at the beginning, to the byte identifying the
encoding. as a result of this error, junk was produced.
instead, call find_charmap so we don't have to hard-code a nontrivial
offset. with this change, the code has been tested and found to work
in the case of converting the affected hkscs characters to utf-8.
Will Dietz [Thu, 3 May 2018 18:44:53 +0000 (13:44 -0500)]
fix iconv conversion to UTF-32 with implicit (big) endianness
maintainer's notes:
commit 95c6044e2ae85846330814c4ac5ebf4102dbe02c split UTF-32 and
UTF-32BE but neglected to add a case for the former as a destination
encoding, resulting in it wrongly being handled by the default case.
the intent was that the value of the macro be chosen to encode "big
endian" in the low bits, so that no code would be needed, but this was
botched; instead, handle it the way UCS2 is handled.
Will Dietz [Tue, 1 May 2018 19:16:44 +0000 (14:16 -0500)]
fix iconv buffer overflow converting to legacy JIS-based encodings
maintainer's notes:
commit a223dbd27ae36fe53f9f67f86caf685b729593fc added the reverse
conversions to JIS-based encodings, but omitted the check for remining
buffer space in the case where the next character to be written was
single-byte, allowing conversion to continue past the end of the
destination buffer.
Rich Felker [Wed, 9 May 2018 04:33:54 +0000 (00:33 -0400)]
make linking of thread-start with explicit scheduling conditional
the wrapper start function that performs scheduling operations is
unreachable if pthread_attr_setinheritsched is never called, so move
it there rather than the pthread_create source file, saving some code
size for static-linked programs.
Rich Felker [Wed, 9 May 2018 04:14:13 +0000 (00:14 -0400)]
improve design of thread-start with explicit scheduling attributes
eliminate the awkward startlock mechanism and corresponding fields of
the pthread structure that were only used at startup.
instead of having pthread_create perform the scheduling operations and
having the new thread wait for them to be completed, start the new
thread with a wrapper start function that performs its own scheduling,
sending the result code back via a futex. this way the new thread can
use storage from the calling thread's stack rather than permanent
fields in the pthread structure.
Rich Felker [Tue, 8 May 2018 02:39:07 +0000 (22:39 -0400)]
clean up and reduce size of internal pthread structure
over time the pthread structure has accumulated a lot of cruft taking
up size. this commit removes unused fields and packs booleans and
other small data more efficiently. changes which would also require
changing code are not included at this time.
non-volatile booleans are packed as unsigned char bitfield members.
the canceldisable and cancelasync fields need volatile qualification
due to how they're accessed from the cancellation signal handler and
cancellable syscalls called from signal handlers. since volatile
bitfield semantics are not clearly defined, discrete char objects are
used instead.
the tid field's type is changed to int because its use is as a value
in futexes, which are defined as plain int. it has no conceptual
relationship to pid_t. also, its position is not ABI.
startlock is reduced to a length-1 array. the second element was
presumably intended as a waiter count, but it was never used and made
no sense, since there is at most one waiter.
Rich Felker [Sun, 6 May 2018 01:33:58 +0000 (21:33 -0400)]
improve joinable/detached thread state handling
previously, some accesses to the detached state (from pthread_join and
pthread_getattr_np) were unsynchronized; they were harmless in
programs with well-defined behavior, but ugly. other accesses (in
pthread_exit and pthread_detach) were synchronized by a poorly named
"exitlock", with an ad-hoc trylock operation on it open-coded in
pthread_detach, whose only purpose was establishing protocol for which
thread is responsible for deallocation of detached-thread resources.
instead, use an atomic detach_state and unify it with the futex used
to wait for thread exit. this eliminates 2 members from the pthread
structure, gets rid of the hackish lock usage, and makes rigorous the
trap added in commit 80bf5952551c002cf12d96deb145629765272db0 for
catching attempts to join detached threads. it should also make
attempt to detach an already-detached thread reliably trap.
Rich Felker [Fri, 4 May 2018 18:26:31 +0000 (14:26 -0400)]
improve pthread_exit synchronization with functions targeting tid
if the last thread exited via pthread_exit, the logic that marked it
dead did not account for the possibility of it targeting itself via
atexit handlers. for example, an atexit handler calling
pthread_kill(pthread_self(), SIGKILL) would return success
(previously, ESRCH) rather than causing termination via the signal.
move the release of killlock after the determination is made whether
the exiting thread is the last thread. in the case where it's not,
move the release all the way to the end of the function. this way we
can clear the tid rather than spending storage on a dedicated
dead-flag. clearing the tid is also preferable in that it hardens
against inadvertent use of the value after the thread has terminated
but before it is joined.
Rich Felker [Fri, 4 May 2018 17:18:51 +0000 (13:18 -0400)]
remove incorrect ESRCH error from pthread_kill
posix documents in the rationale and future directions for
pthread_kill that, since the lifetime of the thread id for a joinable
thread lasts until it is joined, ESRCH is not a correct error for
pthread_kill to produce when the target thread has exited but not yet
been joined, and that conforming applications cannot attempt to detect
this state. future versions of the standard may explicitly require
that ESRCH not be returned for this case.
Rich Felker [Wed, 2 May 2018 16:13:43 +0000 (12:13 -0400)]
use a dedicated futex object for pthread_join instead of tid field
the tid field in the pthread structure is not volatile, and really
shouldn't be, so as not to limit the compiler's ability to reorder,
merge, or split loads in code paths that may be relevant to
performance (like controlling lock ownership).
however, use of objects which are not volatile or atomic with futex
wait is inherently broken, since the compiler is free to transform a
single load into multiple loads, thereby using a different value for
the controlling expression of the loop and the value passed to the
futex syscall, leading the syscall to block instead of returning.
reportedly glibc's pthread_join was actually affected by an equivalent
issue in glibc on s390.
add a separate, dedicated join_futex object for pthread_join to use.
Rich Felker [Tue, 1 May 2018 20:56:02 +0000 (16:56 -0400)]
optimize sigisemptyset
the static const zero set ended up getting put in bss instead of
rodata, wasting writable memory, and the call to memcmp was
size-inefficient. generally for nonstandard extension functions we try
to avoid poking at any internals directly, but the way the zero set
was setup was arguably already doing so.
Rich Felker [Tue, 1 May 2018 18:46:59 +0000 (14:46 -0400)]
avoid excessive stack usage in getcwd
to support the GNU extension of allocating a buffer for getcwd's
result when a null pointer is passed without incurring a link
dependency on free, we use a PATH_MAX-sized buffer on the stack and
only duplicate it to allocated storage after the operation succeeds.
unfortunately this imposed excessive stack usage on all callers,
including those not making use of the GNU extension.
instead, use a VLA to make stack allocation conditional.
Rich Felker [Tue, 1 May 2018 18:34:22 +0000 (14:34 -0400)]
work around arm gcc's rejection of r7 asm constraints in thumb mode
in thumb mode, r7 is the ABI frame pointer register, and unless frame
pointer is disabled, gcc insists on treating it as a fixed register,
refusing to spill it to satisfy constraints. unfortunately, r7 is also
used in the syscall ABI for passing the syscall number.
up til now we just treated this as a requirement to disable frame
pointer when generating code as thumb, but it turns out gcc forcibly
enables frame pointer, and the fixed register constraint that goes
with it, for functions which contain VLAs. this produces an
unacceptable arch-specific constraint that (non-arm-specific) source
files making syscalls cannot use VLAs.
as a workaround, avoid r7 register constraints when producing thumb
code and instead save/restore r7 in a temp register as part of the asm
block. at some point we may want/need to support armv6-m/thumb1, so
the asm has been tweaked to be thumb1-compatible while also
near-optimal for thumb2: it allows the temp and/or syscall number to
be in high registers (necessary since r0-r5 may all be used for
syscalll args) and in thumb2 mode allows the syscall number to be an
8-bit immediate.
getopt_long_only: don't prefix-match long-options that match short ones
for getopt_long, partial (prefix) matches of long options always begin
with "--" and thus can never be ambiguous with a short option. for
getopt_long_only, though, a single-character option can match both a
short option and as a prefix for a long option. in this case, we
wrongly interpreted it as a prefix for the long option.
introduce a new pass, only in long-only mode, to check the prefix
match against short options before accepting it. the only reason
there's a slightly nontrivial loop being introduced rather than strchr
is that our getopt already supports multibyte short options, and
getopt_long_long should handle them consistently. a temp buffer and
strstr could have been used, but the code to set it up would be just
as large as what's introduced here and it would unnecessarily pull in
relatively large code for strstr.
reintroduce hardening against partially-replaced allocator
commit 618b18c78e33acfe54a4434e91aa57b8e171df89 removed the previous
detection and hardening since it was incorrect. commit 72141795d4edd17f88da192447395a48444afa10 already handled all that
remained for hardening the static-linked case. in the dynamic-linked
case, have the dynamic linker check whether malloc was replaced and
make that information available.
with these changes, the properties documented in commit c9f415d7ea2dace5bf77f6518b6afc36bb7a5732 are restored: if calloc is
not provided, it will behave as malloc+memset, and any of the
memalign-family functions not provided will fail with ENOMEM.
return chunks split off by memalign using __bin_chunk instead of free
this change serves multiple purposes:
1. it ensures that static linking of memalign-family functions will
pull in the system malloc implementation, thereby causing link errors
if an attempt is made to link the system memalign functions with a
replacement malloc (incomplete allocator replacement).
2. it eliminates calls to free that are unpaired with allocations,
which are confusing when setting breakpoints or tracing execution.
as a bonus, making __bin_chunk external may discourage aggressive and
unnecessary inlining of it.
using malloc implementation types/macros/idioms for memalign
the generated code should be mostly unchanged, except for explicit use
of C_INUSE in place of copying the low bits from existing chunk
headers/footers.
these changes also remove mild UB due to dubious arithmetic on
pointers into imaginary size_t[] arrays.
commit c9f415d7ea2dace5bf77f6518b6afc36bb7a5732 included checks to
make calloc fallback to memset if used with a replaced malloc that
didn't also replace calloc, and the memalign family fail if free has
been replaced. however, the checks gave false positives for
replacement whenever malloc or free resolved to a PLT entry in the
main program.
for now, disable the checks so as not to leave libc in a broken state.
this means that the properties documented in the above commit are no
longer satisfied; failure to replace calloc and the memalign family
along with malloc is unsafe if they are ever called.
the calloc checks were correct but useless for static linking. in both
cases (simple or full malloc), calloc and malloc are in a source file
together, so replacement of one but not the other would give linking
errors. the memalign-family check was useful for static linking, but
broken for dynamic as described above, and can be replaced with a
better link-time check.
To avoid unexpected results when building for ARMv6KZ with clang, the
correct form of the macro (ie 6KZ) needs to be tested. The incorrect
form of the macro (ie 6ZK) still needs to be tested for compatibility
with pre-2015 versions of gcc.
Andre McCurdy [Thu, 19 Apr 2018 00:41:00 +0000 (17:41 -0700)]
provide optimized a_ctz_32 for arm
Provide an ARM specific a_ctz_32 helper function for architecture
versions for which it can be implemented efficiently via the "rbit"
instruction (ie all Thumb-2 capable versions of ARM v6 and above).
allow interposition/replacement of allocator (malloc)
replacement is subject to conditions on the replacement functions.
they may only call functions which are async-signal-safe, as specified
either by POSIX or as an implementation-defined extension. if any
allocator functions are replaced, at least malloc, realloc, and free
must be provided. if calloc is not provided, it will behave as
malloc+memset. any of the memalign-family functions not provided will
fail with ENOMEM.
in order to implement the above properties, calloc and __memalign
check that they are using their own malloc or free, respectively.
choice to check malloc or free is based on considerations of
supporting __simple_malloc. in order to make this work, calloc is
split into separate versions for __simple_malloc and full malloc;
commit ba819787ee93ceae94efd274f7849e317c1bff58 already did most of
the split anyway, and completing it saves an extra call frame.
previously, use of -Bsymbolic-functions made dynamic interposition
impossible. now, we are using an explicit dynamic-list, so add
allocator functions to the list. most are not referenced anyway, but
all are added for completeness.
fix stdio lock dependency on read-after-free not faulting
instead of using a waiters count, add a bit to the lock field
indicating that the lock may have waiters. threads which obtain the
lock after contending for it will perform a potentially-spurious wake
when they release the lock.
the existing laddr function for fdpic cannot translate ELF virtual
addresses outside of the LOAD segments to runtime addresses because
the fdpic loadmap only covers the logically-mapped part. however the
whole point of reclaim_gaps is to recover the slack space up to the
page boundaries, so it needs to work with such addresses.
add a new laddr_pg function that accepts any address in the page range
for the LOAD segment by expanding the loadmap records out to page
boundaries. only use the new version for reclaim_gaps, so as not to
impact performance of other address lookups.
also, only use laddr_pg for the start address of a gap; the end
address lies one byte beyond the end, potentially in a different page
where it would get mapped differently. instead of mapping end, apply
the length (end-start) to the mapped value of start.
use explicit dynamic-list rather than symbolic-functions for linking
we have always bound symbols at libc.so link time rather than runtime
to minimize startup-time relocations and overhead of calls through the
PLT, and possibly also to preclude interposition that would not work
correctly anyway if allowed. historically, binding at link-time was
also necessary for the dynamic linker to work, but the dynamic linker
bootstrap overhaul in commit f3ddd173806fd5c60b3f034528ca24542aecc5b9
made it unnecessary.
our use of -Bsymbolic-functions, rather than -Bsymbolic, was chosen
because the latter is incompatible with public global data; it makes
it incompatible with copy relocations in the main program. however,
not all global data needs to be public. by using --dynamic-list
instead with an explicit list, we can reduce the number of symbolic
relocations left for runtime.
this change will also allow us to permit interposition of specific
functions (e.g. the allocator) if/when we want to, by adding them to
the dynamic list.
the Linux SYS_nice syscall is unusable because it does not return the
newly set priority. always use SYS_setpriority. also avoid overflows
in addition of inc by handling large inc values directly without
examining the old nice value.
Implementation of __malloc0 in malloc.c takes care to preserve zero
pages by overwriting only non-zero data. However, malloc must have
already modified auxiliary heap data just before and beyond the
allocated region, so we know that edge pages need not be preserved.
For allocations smaller than one page, pass them immediately to memset.
Otherwise, use memset to handle partial pages at the head and tail of
the allocation, and scan complete pages in the interior. Optimize the
scanning loop by processing 16 bytes per iteration and handling rest of
page via memset as soon as a non-zero byte is found.
the catan implementation from OpenBSD includes a FIXME-annotated
"overflow" branch that produces a meaningless and incorrect
large-magnitude result. it was reachable via three paths,
corresponding to gotos removed by this commit, in order:
1. pure imaginary argument with imaginary component greater than 1 in
magnitude. this case does not seem at all exceptional and is
handled (at least with the quality currently expected from our
complex math functions) by the existing non-exceptional code path.
2. arguments on the unit circle, including the pure-real argument 1.0.
these are not exceptional except for ±i, which should produce
results with infinite imaginary component and which lead to
computation of atan2(±0,0) in the existing non-exceptional code
path. such calls to atan2() however are well-defined by POSIX.
3. the specific argument +i. this route should be unreachable due to
the above (2), but subtle rounding effects might have made it
possible in rare cases. continuing on the non-exceptional code path
in this case would lead to computing the (real) log of an infinite
argument, then producing a NAN when multiplying it by I.
for now, remove the exceptional code paths entirely. replace the
multiplication by I with construction of a complex number using the
CMPLX macro so that the NAN issue (3) prevented cannot arise.
with these changes, catan should give reasonably correct results for
real arguments, and should no longer give completely-wrong results for
pure-imaginary arguments outside the interval (-i,+i).
fix wrong result in casin and many related complex functions
the factor of -i noted in the comment at the top of casin.c was
omitted from the actual code, yielding a result rotated 90 degrees and
propagating into errors in other functions defined in terms of casin.
implement multiplication by -i as a rotation of the real and imaginary
parts of the result, rather than by actual multiplication, since the
latter cannot be optimized without knowledge that the operand is
finite. here, the rotation is the actual intent, anyway.
Samuel Holland [Sat, 7 Apr 2018 14:47:16 +0000 (09:47 -0500)]
implement wcsftime padding specifier extensions
Commit 8a6bd7307da3fc4d08dd6a9277b611ccb4971354 added support for
padding specifier extensions to strftime, but did not modify wcsftime.
In the process, it added a parameter to __strftime_fmt_1 in strftime.c,
but failed to update the prototype in wcsftime.c. This was found by
compiling musl with LTO:
src/time/wcsftime.c:7:13: warning: type of '__strftime_fmt_1' does \
not match original declaration [-Wlto-type-mismatch]
Fix the prototype of __strftime_fmt_1 in wcsftime.c, and generate the
'pad' argument the same way as it is done in strftime.
prevent bypass of guarantee that suids start with fd 0/1/2 open
it was reported by Erik Bosman that poll fails without setting revents
when the nfds argument exceeds the current value for RLIMIT_NOFILE,
causing the subsequent open calls to be bypassed. if the rlimit is
either 1 or 2, this leaves fd 0 and 1 potentially closed but openable
when the application code is reached.
based on a brief reading of the poll syscall documentation and code,
it may be possible for poll to fail under other attacker-controlled
conditions as well. if it turns out these are reasonable conditions
that may happen in the real world, we may have to go back and
implement fallbacks to probe each fd individually if poll fails, but
for now, keep things simple and treat all poll failures as fatal.
Szabolcs Nagy [Sun, 1 Apr 2018 20:02:01 +0000 (20:02 +0000)]
fix fmaf wrong result
if double precision r=x*y+z is not a half way case between two single
precision floats or it is an exact result then fmaf returns (float)r.
however the exactness check was wrong when |x*y| < |z| and could cause
incorrectly rounded result in nearest rounding mode when r is a half
way case.
fmaf(-0x1.26524ep-54, -0x1.cb7868p+11, 0x1.d10f5ep-29)
was incorrectly rounded up to 0x1.d117ap-29 instead of 0x1.d1179ep-29.
(exact result is 0x1.d1179efffffffecp-29, r is 0x1.d1179fp-29)
Rich Felker [Wed, 28 Mar 2018 19:53:45 +0000 (15:53 -0400)]
fix default feature profile in tar.h
commit d93c0740d86aaf7043e79b942a6c0b3f576af4c8 added use of feature
test macros without including features.h, causing a definition that
should be exposed in the default profile, TSVTX, to appear only when
_XOPEN_SOURCE or higher is explicitly defined.
Rich Felker [Sun, 25 Mar 2018 02:47:36 +0000 (22:47 -0400)]
adjust makefile target-specific CFLAGS rules to be more robust & complete
previously, MEMOPS_SRCS failed to include arch-specific replacement
files for memcpy, etc., omitting CFLAGS_MEMOPS and thereby potentially
causing build failure if an arch provided C (rather than asm)
replacements for these files.
instead of trying to explicitly include all the files that might have
arch replacements, which is prone to human error, extract final names
to be used out of $(LIBC_OBJS), where the rules for arch replacements
have already been applied. do the same for NOSSP_OBJS, using CRT_OBJS
and LDSO_OBJS rather than repeating ourselves with $(wildcard...) and
explicit pathnames again.
Rich Felker [Sun, 11 Mar 2018 01:45:49 +0000 (20:45 -0500)]
explicitly use signed keyword to define intNN_t and derivative types
standing alone, both the signed and int keywords identify the same
type, a (signed) int. however the C language has an exception where,
when the lone keyword int is used to declare a bitfield, it's
implementation-defined whether the bitfield is signed or unsigned. C11
footnote 125 extends this implementation-definedness to typedefs, and
DR#315 extends it to other integer types (for which support with
bitfields is implementation-defined).
while reasonable ABIs (all the ones we support) define bitfields as
signed by default, GCC and compatible compilers offer an option
-funsigned-bitfields to change the default. while any signed types
defined without explicit use of the signed keyword are affected, the
stdint.h types, especially intNN_t, have a natural use in bitfields.
ensure that bitfields defined with these types always have the correct
signedness regardless of compiler & flags used.
Rich Felker [Sat, 10 Mar 2018 23:08:02 +0000 (18:08 -0500)]
fix minor namespace issues in termios.h
the output delay features (NL*, CR*, TAB*, BS*, and VT*) are
XSI-shaded. VT* is in the V* namespace reservation but the rest need
to be suppressed in base POSIX namespace.
unfortunately this change introduces feature test macro checks into
another bits header. at some point these checks should be simplified
by having features.h handle the "FTM X implies Y" relationships.
Rich Felker [Sat, 10 Mar 2018 23:03:17 +0000 (18:03 -0500)]
remove spurious const keyword in sigqueue declaration
this must have been taken from POSIX without realizing that it was
meaningless. the resolution to Austin Group issue #844 removed it from
the standard.
Rich Felker [Sat, 10 Mar 2018 22:47:14 +0000 (17:47 -0500)]
reverse definition dependency between PAGESIZE and PAGE_SIZE
PAGESIZE is actually the version defined in POSIX base, with PAGE_SIZE
being in the XSI option. use PAGESIZE as the underlying definition to
facilitate making exposure of PAGE_SIZE conditional.
Rich Felker [Wed, 7 Mar 2018 16:22:38 +0000 (11:22 -0500)]
fix nl_langinfo_l(CODESET, loc) reporting wrong locale's value
use of MB_CUR_MAX encoded a hidden dependency on the currently active
locale for the calling thread, whereas nl_langinfo_l is supposed to
report for the locale passed as an argument.
Rich Felker [Mon, 26 Feb 2018 02:13:38 +0000 (21:13 -0500)]
add public interface headers to implementation files
general policy is that all source files defining a public API or an
ABI mechanism referenced by a public header should include the public
header that declares the interface, so that the compiler or analysis
tools can check the consistency of the declarations. Alexander Monakov
pointed out a number of violations of this principle a few years back.
fix them now.
Rich Felker [Sat, 24 Feb 2018 21:45:33 +0000 (16:45 -0500)]
fix aliasing violations in fgetpos/fsetpos
add a member of appropriate type to the fpos_t union so that accesses
are well-defined. use long long instead of off_t since off_t is not
always exposed in stdio.h and there's no namespace-clean alias for it.
access is still performed using pointer casts rather than by naming
the union member as a matter of style; to the extent possible, the
naming of fields in opaque types defined in the public headers is not
treated as an API contract with the implementation. access via the
pointer cast is valid as long as the union has a member of matching
type.
Rich Felker [Sat, 24 Feb 2018 17:33:06 +0000 (12:33 -0500)]
use idiomatic safe form for FUNLOCK macro
previously this macro used an odd if/else form instead of the more
idiomatic do/while(0), making it unsafe against omission of trailing
semicolon. the omission would make the following statement conditional
instead of producing an error.
Rich Felker [Sat, 24 Feb 2018 16:33:18 +0000 (11:33 -0500)]
remove useless and confusing parentheses in stdio __towrite function
they seem to be relics of e3cd6c5c265cd481db6e0c5b529855d99f0bda30
where this code was refactored from a check that previously masked
against (F_ERR|F_NOWR) instead of just F_NOWR.
Rich Felker [Sat, 24 Feb 2018 16:19:54 +0000 (11:19 -0500)]
avoid use of readv syscall in __stdio_read backend when not needed
formally, calling readv with a zero-length first iov component should
behave identically to calling read on just the second component, but
presence of a zero-length iov component has triggered bugs in some
kernels and performs significantly worse than a simple read on some
file types.
Rich Felker [Sat, 24 Feb 2018 15:51:16 +0000 (10:51 -0500)]
consistently return number of bytes read from stdio read backend
the stdio FILE read backend's return type is size_t, not ssize_t, and
all of the special (non-fd-backed) FILE types already return the
number of bytes read (zero) on error or eof. only __stdio_read leaked
a syscall error return into its return value.
fread had a workaround for this behavior going all the way back to the
original check-in. remove the workaround since it's no longer needed.
Rich Felker [Sat, 24 Feb 2018 15:26:26 +0000 (10:26 -0500)]
fix getopt wrongly treating colons in optstring as valid option chars
the ':' in optstring has special meaning as a flag applying to the
previous option character, or to getopt's error handling behavior when
it appears at the beginning. don't also accept a "-:" option based on
its presence.
Rich Felker [Fri, 23 Feb 2018 07:54:01 +0000 (02:54 -0500)]
add getentropy function
based loosely on patch by Hauke Mehrtens; converted to wrap the public
API of the underlying getrandom function rather than direct syscalls,
so that if/when a fallback implementation of getrandom is added it
will automatically get picked up by getentropy too.
Szabolcs Nagy [Tue, 6 Feb 2018 22:33:38 +0000 (22:33 +0000)]
elf.h: add DT_SYMTAB_SHNDX
it's a recent addition to elf gabi:
http://sco.com/developers/gabi/latest/revision.html
based on discussions at
https://sourceware.org/bugzilla/show_bug.cgi?id=15835
Szabolcs Nagy [Mon, 27 Nov 2017 01:16:14 +0000 (01:16 +0000)]
mips,powerpc: fix TIOCSER_TEMT in termios.h
use the same token to define TIOCSER_TEMT as is used in ioctl.h
so when both headers are included there are no redefinition warnings
during musl build.
projects / musl / log