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.
previously, the pthread_attr_t object was always initialized all-zero,
and stack/guard size were represented as differences versus their
defaults. this required lots of confusing offset arithmetic everywhere
they were used. instead, have pthread_attr_init fill in the default
values, and work with absolute sizes everywhere.
the swprintf write callback never reset its buffer pointers, so after
its 256-byte buffer filled up, it would keep repeating those bytes
over and over in the output until the destination buffer filled up. it
also failed to set the error indicator for the stream on EILSEQ,
potentially allowing output to continue after the error.
the overflow check for years+100 did not account for the extra
year computed from the remaining months. instead, perform this
check after obtaining the final number of years.
the old snprintf design setup the FILE buffer pointers to point
directly into the destination buffer; if n was actually larger than
the buffer size, the pointer arithmetic to compute the buffer end
pointer was undefined. this affected sprintf, which is implemented in
terms of snprintf, as well as some unusual but valid direct uses of
snprintf.
instead, setup the FILE as unbuffered and have its write function
memcpy to the destination. the printf core sets up its own temporary
buffer for unbuffered streams.
the _CS_V6_ENV and _CS_V7_ENV constants are required to be available for use
with confstr. glibc defines these constants with values 1148 and 1149,
respectively.
the only missing (and required) confstr constants are
_CS_POSIX_V7_THREADS_CFLAGS and _CS_POSIX_V7_THREADS_LDFLAGS which remain
unavailable in glibc.
commit 6ffdc4579f set lnz in the code
path for non-zero digits after a huge string of zeros, but the
assignment of dc to lnz truncates if the value of dc does not fit in
int; this is possible for some pathologically long inputs, either via
strings on 64-bit systems or via scanf-family functions.
instead, simply set lnz to match the point at which we add the
artificial trailing 1 bit to simulate nonzero digits after a huge
run of zeros.
the mid-sized integer optimization relies on lnz set up properly
to mark the last non-zero decimal digit, but this was not done
if the non-zero digit lied outside the KMAX digits of the base
10^9 number representation.
so if the fractional part was a very long list of zeros (>2048*9 on
x86) followed by non-zero digits then the integer optimization could
kick in discarding the tiny non-zero fraction which can mean wrong
result on non-nearest rounding mode.
strtof, strtod and strtold were all affected.
in certain cases excessive trailing zeros could cause incorrect
rounding from long double to double or float in decfloat.
e.g. in strtof("9444733528689243848704.000000", 0) the argument
is 0x1.000001p+73, exactly halfway between two representible floats,
this incorrectly got rounded to 0x1.000002p+73 instead of 0x1p+73,
but with less trailing 0 the rounding was fine.
the fix makes sure that the z index always points one past the last
non-zero digit in the base 10^9 representation, this way trailing
zeros don't affect the rounding logic.
in nearest rounding mode exact halfway cases were not following the
round to even rule if the rounding happened at a base 1000000000 digit
boundary of the internal representation and the previous digit was odd.
e.g. printf("%.0f", 1.5) printed 1 instead of 2.
posix requires that EINVAL be returned if the first parameter specifies
the cpu-time clock of the calling thread (CLOCK_THREAD_CPUTIME_ID).
linux returns ENOTSUP instead so we handle this.
j is int32_t and thus j<<31 is undefined if j==1, so j is changed to
uint32_t locally as a quick fix, the generated code is not affected.
(this is a strict conformance fix, future c standard may allow 1<<31,
see DR 463. the bug was inherited from freebsd fdlibm, the proper fix
is to use uint32_t for all bit hacks, but that requires more intrusive
changes.)
reported by Daniel Sabogal
overlayfs may have fairly long lines so we use getline to allocate a
buffer dynamically. The buffer will be allocated on first use, expand as
needed, but will never be free'ed.
Downstream bug: http://bugs.alpinelinux.org/issues/5703
Signed-off-by: Natanael Copa <[email protected]>
this patch fixes a large number of missed internal signed-overflow
checks and errors in determining when the return value (output length)
would exceed INT_MAX, which should result in EOVERFLOW. some of the
issues fixed were reported by Alexander Cherepanov; others were found
in subsequent review of the code.
aside from the signed overflows being undefined behavior, the
following specific bugs were found to exist in practice:
- overflows computing length of floating point formats with huge
explicit precisions, integer formats with prefix characters and huge
explicit precisions, or string arguments or format strings longer
than INT_MAX, resulted in wrong return value and wrong %n results.
- literal width and precision values outside the range of int were
misinterpreted, yielding wrong behavior in at least one well-defined
case: string formats with precision greater than INT_MAX were
sometimes truncated.
- in cases where EOVERFLOW is produced, incorrect values could be
written for %n specifiers past the point of exceeding INT_MAX.
in addition to fixing these bugs, we now stop producing output
immediately when output length would exceed INT_MAX, rather than
continuing and returning an error only at the end.
if the requested precision is close to INT_MAX, adding
LDBL_MANT_DIG/3+8 overflows. in practice the resulting undefined
behavior manifests as a large negative result, which is then used to
compute the new end pointer (z) with a wildly out-of-bounds value
(more overflow, more undefined behavior). the end result is at least
incorrect output and character count (return value); worse things do
not seem to happen, but detailed analysis has not been done.
this patch fixes the overflow by performing the intermediate
computation as unsigned; after division by 9, the final result
necessarily fits in int.
we inherited from TRE regexec code that's utterly wrong with respect
to the integer types it's using. while it doesn't appear that
compilers are producing unsafe output, signed integer overflows seem
to happen, and regexec fails to find matches past offset INT_MAX.
this patch fixes the type of all variables/fields used to store
offsets in the string from int to regoff_t. after the changes, basic
testing showed that regexec can now find matches past 2GB (INT_MAX)
and past 4GB on x86_64, and code generation is unchanged on i386.
most of the possible overflows were already ruled out in practice by
regcomp having already succeeded performing larger allocations.
however at least the num_states*num_tags multiplication can clearly
overflow in practice. for safety, check them all, and use the proper
type, size_t, rather than int.
also improve comments, use calloc in place of malloc+memset, and
remove bogus casts.
this is a clone of the fix to the gethostby*_r functions in
commit fe82bb9b92. the man pages
document that the getservby*_r functions set this pointer to
NULL if there was an error or if no record was found.
