the code being removed was written to optimize for size assuming the
compiler cannot collapse code paths for different types with the same
underlying representation. modern compilers sometimes succeed in
making this optimization themselves, but either way it's a small size
difference and not worth the source-level complexity or the UB
involved in this hack.
some incorrect use of va_arg still remains, particularly use of void *
where the actual argument has a different pointer type. fixing this
requires some actual code additions, rather than just removing cruft,
so I'm leaving it to be done later as a separate commit.
commit 0a950dcf15 added checking that
the pathname a tty device was opened with actually matches the device,
which can fail to hold when a container inherits a tty from outside
the container. the error code added at the time was ENOENT; however,
discussions between affected applications and glibc developers
resulted in glibc adopting ENODEV as the error for this condition, and
this has now been documented in the man pages project as well. adopt
the same error code for consistency.
patch by Christian Brauner.
commit d6cb08bcac moved the code and
introduced an incorrect string offset for the new parsing, probably
due to a copy-and-paste error.
patch by Stefan Sedich.
in nearest rounding mode scalbn could introduce double rounding error
when an intermediate value and the final result were both in the
subnormal range e.g.
scalbn(0x1.7ffffffffffffp-1, -1073)
returned 0x1p-1073 instead of 0x1p-1074, because the intermediate
computation got rounded to 0x1.8p-1023.
with the fix an intermediate value can only be in the subnormal range
if the final result is 0 which is correct even after double rounding.
(there still can be two roundings so signals may be raised twice, but
that's only observable with trapping exceptions which is not supported.)
normally 32-bit archs use the mmap2 syscall and are limited to an
offset of 2^32 pages. however some 32-bit archs (mainly ILP32-on-64
ones like x32) have 64-bit syscall argument slots and thus can accept
the full range. don't artifically limit them.
analogous to commit 5bf7eba213, use of
AT_PHDR/PT_PHDR does not actually work to find the program base, and
the method with _DYNAMIC vs PT_DYNAMIC must be used as an alternative.
patch by Shiz, along with testing to confirm that this fixes unwinding
in static PIE.
due to testing buf[i].family==AF_INET before checking i==cnt, it was
possible to read past the end of the array, or past the valid part. in
practice, without active bounds/indeterminate-value checking by the
compiler, the worst that happened was failure to return early and
optimize out the sorting that's unneeded for v4-only results.
returning on i==cnt-1 rather than i==cnt would be an alternate fix,
but the approach this patch takes is more idiomatic and less
error-prone.
patch by Timo Teräs.
this should increase performance and reduce code size on aarch64.
the compiled code was checked against using __builtin_* instead
of inline asm with gcc-6.2.0.
lrint is two instructions.
c with inline asm is used because it is safer than a pure asm
implementation, this prevents ll{rint,round} to be an alias
of l{rint,round} (because the types don't match) and depends
on gcc style inline asm support.
ceil, floor, round, trunc can either raise inexact on finite
non-integer inputs or not raise any exceptions. the new
implementation does not raise exceptions while the generic
c code does.
on aarch64, the underflow exception is signaled before rounding
(ieee 754 allows both before and after rounding, but it must be
consistent), the generic fma c code signals it after rounding
so using single instruction fixes a slight conformance issue too.
With REG_NEWLINE, POSIX says:
"A <newline> in string shall not be matched by a period outside
a bracket expression or by any form of a non-matching list"
the old limit was one byte too short to support locale names of the
form xx_XX.UTF-8@modifier where modifier is more than 3 bytes, a form
which various real-world locale names take. the problem could be
avoided by omitting the useless ".UTF-8" part, but users may need to
have it present when operating on mixed-libc systems or when it will
be carried over (e.g. across ssh) to other systems.
the new limit is chosen sufficient for existing/reasonable locale
names while still keeping the size of setlocale's static buffer small.
also add locale_impl.h to the Makefile's list of headers which force
rebuild of source files, to prevent dangerously inconsistent object
files from getting used after this change.
often translations will be named only by language, whereas locale
names may also include a territory code, modifier, and codeset
portion. previously, only translations exactly matching the locale
name were loaded. this was a major usability issue, requiring
workarounds like symlinks or tweaking of the locale name.
with these changes, gettext now searches for translations by first
removing the codeset portion of the locale name, then trying the
remainder in full, with modifier (@mod) removed, with territory code
(_XX) removed, and with both removed.
part of the reason gettext lacked support for searching fallbacks
before is that the candidate pathname for a translation file was
constructed on each call and used as the key to lookup an
already-mapped translation file. this was very costly/inefficient. we
now use the tuple of textdomain binding pointer, locale map pointer,
and integer category id as the key for looking up a translation file
mapping.
based on patch by He X.
when called for LC_ALL, setlocale has to return a string representing
the state of all locale categories. the simplest way to do this was to
always return a delimited list of values for each category, but that's
not friendly in the fairly common case where all categories have the
same setting. He X proposed a patch to check for this case and return
a single name; this patch is a simplified approach to do the same.
the time of day at which daylight time switches over is specified in
local time in the dst state prior to the transition. the code for
handling this wrongly assumed it needed to switch whether dst or
standard offset is applied to the transition time when the dst end
date is before the dst start date (souther hemisphere summer), but in
fact the end transition time should always be adjusted for dst, and
the start transition time should always be adjusted for standard time.
partly following freebsd rev 279491
https://svnweb.freebsd.org/base?view=revision&revision=279491
(musl had some of the fixes before freebsd).
the change should not matter much for j0f, y0f, but it improves
j1f and y1f in [2.5,~3.75] (that is [0x40200000,~0x40700000]).
near roots (e.g. around 3.8317 for j1f) there are still large
ulp errors.
dropped code that tried to raise inexact.
the fix in commit c3edc06d1e for
CVE-2016-8859 used gotos to exit on overflow conditions, but the code
in that error path assumed the buffer pointer was valid or null. thus,
the conditions which previously led to under-allocation and buffer
overflow could instead lead to an invalid pointer being passed to
free.
this is not a conformance issue as posix does not specify the
argument order, but the order is specified for bsearch and some
systems document the order for lsearch consistently (openbsd).
since there were two indpendent reports of this issue it's better
to use the more widely expected argument order.
binutils commit bada43421274615d0d5f629a61a60b7daa71bc15 tightened
immediate fixup handling in gas in such a way that the final .arch of
an object file must be compatible with the fixups used when the
instruction was assembled; this in turn broke assembling of atomics.s,
at least in thumb mode.
it's not clear whether this should be considered a bug in gas, but
.object_arch is preferable anyway for our purpose here of controlling
the ISA level tag on the object file being produced, and it's the
intended directive for use in object files with runtime code
selection. research by Szabolcs Nagy confirmed that .object_arch is
supported in all relevant versions of binutils and clang's integrated
assembler.
patch by Reiner Herrmann.
the plural_rule field of allocated msgcat structures was assumed to be
initially-null but was never initialized. for future-proofing, the
nplurals field which was left uninitialized should also be cleared.
likewise, in the binding structure, the active field could be used
uninitialized by a technicality: the a_store which stores the initial
value of 0 may be implemented as a cas operation, which reads the old
value.
rather than fixing these issues individually, just use calloc for both
allocations. this does result in wasteful clearing of name buffers (up
to NAME_MAX+PATH_MAX) before filling them, but since the size if
bounded and the time is dominated by filesystem operations, it really
doesn't matter; simplicity and future-proofing have more value here.
modified from patch submitted by He X.
this loop was only supposed to deactivate other bindings for the same
text domain name, but due to copy-and-paste error, deactivated all
other bindings.
patch by He X.
commit 78a8ef47c4 inadvertently removed
the SA_RESTART flag from the sigaction for the internal signal handler
used by __synccall for broadcasting. as a result, programs which did
not use interrupting signals but which used set*id() in a
multithreaded context could wrongly observe EINTR errors they're not
prepared to handle.
ISO C and POSIX only specify behavior for base arguments of 0 and
2-36; POSIX mandates an EINVAL error for unsupported bases. it's not
clear that there's a requirement for implementations not to "support"
additional bases as an extension, but "base 1" did not work in any
meaningful way anyway, so it should be considered unsupported and thus
an error.
getopt is only specified to modify optopt on error, and some software
apparently infers an error from optopt!=0.
getopt_long is changed analogously. the resulting behavior differs
slightly from the behavior of the GNU implementation of getopt_long,
which keeps an internal shadow copy of optopt and copies it to the
public one on return, but since the GNU implementation also exhibits
this shadow-copy behavior for plain getopt where is is non-conforming,
I think this can reasonably be considered a bug rather than an
intentional behavior that merits mimicing.
commit 0dc99ac413 added input length
checking to avoid unsafe VLA allocation, but put it in the wrong
place, before the glob_t structure was zeroed out. while POSIX isn't
clear on whether it's permitted to call globfree after glob failed
with GLOB_NOSPACE, making it safe is clearly better than letting
uninitialized pointers get passed to free in non-conforming callers.
while we're fixing this, change strlen check to the idiomatic strnlen
version to avoid unbounded input scanning before returning an error.
commit 583ea83541 fixed the case where
tm_year is negative but the resulting year (offset by 1900) was still
positive, which is always the case for time_t values that fit in 32
bits, but not for arbitrary inputs.
based on an earlier patch by Julien Ramseier which was overlooked at
the time the previous fix was applied.
the static-linked version of __init_tls needs to locate the TLS
initialization image via the ELF program headers, which requires
determining the base address at which the program was loaded. the
existing code attempted to do this by comparing the actual address of
the program headers (obtained via auxv) with the virtual address for
the PT_PHDR record in the program headers. however, the linker seems
to produce a PT_PHDR record only when a program interpreter (dynamic
linker) is used. thus the computation failed and used the default base
address of 0, leading to a crash when trying to access the TLS image
at the wrong address.
the dynamic linker entry point and static-PIE rcrt1.o startup code
compute the base address instead by taking the difference between the
run-time address of _DYNAMIC and the virtual address in the PT_DYNAMIC
record. this patch copies the approach they use, but with a weak
symbolic reference to _DYNAMIC instead of obtaining the address from
the crt_arch.h asm. this works because relocations have already been
performed at the time __init_tls is called.
three problems are addressed:
- use of pc arithmetic, which was difficult if not impossible to make
correct in thumb mode on all models, so that relative rather than
absolute pointers to the backends could be used. this was designed
back when there was no coherent model for the early stages of the
dynamic linker before relocations, and is no longer necessary.
- assumption that data (the relative pointers to the backends) can be
accessed at a constant displacement from the code. this will not be
possible on future fdpic subarchs (for cortex-m), so move
responsibility for loading the backend code address to the caller.
- hard-coded arm opcodes using the .word directive. instead, use the
.arch directive to work around the assembler's refusal to assemble
instructions not available (or in some cases, available but just
considered deprecated) in the target isa level. the obscure v6t2
arch is used for v6 code so as to (1) allow generation of thumb2
output if -mthumb is active, and (2) avoid warnings/errors for mcr
barriers that clang would produce if we just set arch to v7-a.
in addition, the __aeabi_read_tp function is moved out of the inner
workings and implemented as an asm wrapper around a C function, so
that asm code does not need to read global data. the asm wrapper
serves to satisfy the ABI calling convention requirements for this
function.
float conversion is slow and big on soft-float targets.
The lookup table increases code size a bit on most hard float targets
(and adds 60byte rodata), performance can be a bit slower because of
position independent data access and cpu internal state dependence
(cache, extra branches), but the overall effect should be minimal
(common, small size allocations should be unaffected).
In BRE, ^ is an anchor at the beginning of an expression, optionally
it may be an anchor at the beginning of a subexpression and must be
treated as a literal otherwise.
Previously musl treated ^ in subexpressions as literal, but at least
glibc and gnu sed treats it as an anchor and that's the more useful
behaviour: it can always be escaped to get back the literal meaning.
Same for $ at the end of a subexpression.
Portable BRE should not rely on this, but there are sed commands in
build scripts which do.
This changes the meaning of the BREs:
\(^a\)
\(a\|^b\)
\(a$\)
\(a$\|b\)
POSIX specifies the result to have signed 32-bit range. on 32-bit
archs, the implicit conversion to long achieved the desired range
already, but when long is 64-bit, a cast is needed.
patch by Ed Schouten.
the bz instruction that was wrongly used only admits a small immediate
displacement and cannot be used with external symbols; apparently the
linker fails to diagnose the overflow.
gdb can only backtrace/unwind across signal handlers if it recognizes
the sa_restorer trampoline. for x86_64, gdb first attempts to
determine the symbol name for the function in which the program
counter resides and match it against "__restore_rt". if no name can be
found (e.g. in the case of a stripped binary), the exact instruction
sequence is matched instead.
when matching the function name, however, gdb's unwind code wrongly
considers the interval [sym,sym+size] rather than [sym,sym+size).
thus, if __restore_rt begins immediately after another function, gdb
wrongly identifies pc as lying within the previous adjacent function.
this patch adds a nop before __restore_rt to preclude that
possibility. it also removes the symbol name __restore and replaces it
with a macro since the stability of whether gdb identifies the
function as __restore_rt or __restore is not clear.
for the no-symbols case, the instruction sequence is changed to use
%rax rather than %eax to match what gdb expects.
based on patch by Szabolcs Nagy, with extended description and
corresponding x32 changes added.
On s390x, the kernel provides AT_SYSINFO_EHDR, but sets it to zero, if the
program being run does not have a program interpreter. This causes
problems when running the dynamic linker directly.
alpha and s390x gratuitously use 64-bit entries (wasting 2x space and
cache utilization) despite the values always being 32-bit.
based on patch by Bobby Bingham, with changes suggested by Alexander
Monakov to use the public Elf_Symndx type from link.h (and make it
properly variable by arch) rather than adding new internal
infrastructure for handling the type.
commit 31fb174dd2 used
DEFAULT_GUARD_SIZE from pthread_impl.h in a static initializer,
breaking build on archs where its definition, PAGE_SIZE, is not a
constant. instead, just define DEFAULT_GUARD_SIZE as 4096, the minimal
page size on any arch we support. pthread_create rounds up to whole
pages anyway, so defining it to 1 would also work, but a moderately
meaningful value is nicer to programs that use
pthread_attr_getguardsize on default-initialized attribute objects.
based on patch by Timo Teräs:
While generally this is a bad API, it is the only existing API to
affect c++ (std::thread) and c11 (thrd_create) thread stack size.
This patch allows applications only to increate stack and guard
page sizes.
commit 33ce920857 broke pthread_create
in the case where a null attribute pointer is passed; rather than
using the default sizes, sizes of 0 (plus the remainder of one page
after TLS/TCB use) were used.
Rich Felker
Szabolcs Nagy
Julien Ramseier
Bobby Bingham
rofl0r