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* decouple struct stat from kernel typeRich Felker2019-07-181-0/+21
| | | | | | | | | | | | | | | presently, all archs/ABIs have struct stat matching the kernel stat[64] type, except mips/mipsn32/mips64 which do conversion hacks in syscall_arch.h to work around bugs in the kernel type. this patch completely decouples them and adds a translation step to the success path of fstatat. at present, this is just a gratuitous copying, but it opens up multiple possibilities for future support for 64-bit time_t on 32-bit archs and for cleaned-up/unified ABIs. for clarity, the mips hacks are not yet removed in this commit, so the mips kstat structs still correspond to the output of the hacks in their syscall_arch.h files, not the raw kernel type. a subsequent commit will fix this.
* add new syscall numbers from linux v5.1Szabolcs Nagy2019-07-011-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syscall numbers are now synced up across targets (starting from 403 the numbers are the same on all targets other than an arch specific offset) IPC syscalls sem*, shm*, msg* got added where they were missing (except for semop: only semtimedop got added), the new semctl, shmctl, msgctl imply IPC_64, see linux commit 0d6040d4681735dfc47565de288525de405a5c99 arch: add split IPC system calls where needed new 64bit time_t syscall variants got added on 32bit targets, see linux commit 48166e6ea47d23984f0b481ca199250e1ce0730a y2038: add 64-bit time_t syscalls to all 32-bit architectures new async io syscalls got added, see linux commit 2b188cc1bb857a9d4701ae59aa7768b5124e262e Add io_uring IO interface linux commit edafccee56ff31678a091ddb7219aba9b28bc3cb io_uring: add support for pre-mapped user IO buffers a new syscall got added that uses the fd of /proc/<pid> as a stable handle for processes: allows sending signals without pid reuse issues, intended to eventually replace rt_sigqueueinfo, kill, tgkill and rt_tgsigqueueinfo, see linux commit 3eb39f47934f9d5a3027fe00d906a45fe3a15fad signal: add pidfd_send_signal() syscall on some targets (arm, m68k, s390x, sh) some previously missing syscall numbers got added as well.
* remove cruft for supposedly-buggy clang from or1k & microblaze syscall_archRich Felker2019-04-101-9/+0
| | | | | | | | | it was never demonstrated to me that this workaround was needed, and seems likely that, if there ever was any clang version for which it was needed, it's old enough to be unusably buggy in other ways. if it turns out some compilers actually can't do the register allocation right, we'll need to replace this with inline shuffling code, since the external __syscall dependency is being removed.
* aarch64, or1k: add kexec_file_load syscall number from linux v5.0Szabolcs Nagy2019-03-131-0/+1
| | | | added in linux commit 4e21565b7fd4d9045765f697887e74a704135fe2
* aarch64, or1k: define rseq syscall number following linux v4.19Szabolcs Nagy2019-03-131-0/+1
| | | | added in linux commit db7a2d1809a5b6b08d138ff68837f805fc073351
* add io_pgetevents and rseq syscall numbers from linux v4.18Szabolcs Nagy2018-12-091-0/+1
| | | | | | | | io_pgetevents is new in linux commit 7a074e96dee62586c935c80cecd931431bfdd0be rseq is new in linux commit d7822b1e24f2df5df98c76f0e94a5416349ff759
* make thread-pointer-loading asm non-volatileRich Felker2018-10-161-2/+2
| | | | | | | | | | this will allow the compiler to cache and reuse the result, meaning we no longer have to take care not to load it more than once for the sake of archs where the load may be expensive. depends on commit 1c84c99913bf1cd47b866ed31e665848a0da84a2 for correctness, since otherwise the compiler could hoist loads during stage 3 of dynamic linking before the initial thread-pointer setup.
* fix TLS layout of TLS variant I when there is a gap above TPSzabolcs Nagy2018-06-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* reverse definition dependency between PAGESIZE and PAGE_SIZERich Felker2018-03-101-1/+1
| | | | | | 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.
* add statx syscall numbers from linux v4.11Szabolcs Nagy2017-11-051-0/+1
| | | | | statx was added in linux commit a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (there is no libc wrapper yet and microblaze and sh misses the number).
* make syscall.h consistent with linuxSzabolcs Nagy2017-09-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | most of the found naming differences don't matter to musl, because internally it unifies the syscall names that vary across targets, but for external code the names should match the kernel uapi. aarch64: __NR_fstatat is called __NR_newfstatat in linux. __NR_or1k_atomic got mistakenly copied from or1k. arm: __NR_arm_sync_file_range is an alias for __NR_sync_file_range2 __NR_fadvise64_64 is called __NR_arm_fadvise64_64 in linux, the old non-arm name is kept too, it should not cause issues. (powerpc has similar nonstandard fadvise and it uses the normal name.) i386: __NR_madvise1 was removed from linux in commit 303395ac3bf3e2cb488435537d416bc840438fcb 2011-11-11 microblaze: __NR_fadvise, __NR_fstatat, __NR_pread, __NR_pwrite had different name in linux. mips: __NR_fadvise, __NR_fstatat, __NR_pread, __NR_pwrite, __NR_select had different name in linux. mipsn32: __NR_fstatat is called __NR_newfstatat in linux. or1k: __NR__llseek is called __NR_llseek in linux. the old name is kept too because that's the name musl uses internally. powerpc: __NR_{get,set}res{gid,uid}32 was never present in powerpc linux. __NR_timerfd was briefly defined in linux but then got renamed.
* add pkey_{mprotect,alloc,free} syscalls from linux v4.9Szabolcs Nagy2016-12-291-0/+3
| | | | | see linux commit e8c24d3a23a469f1f40d4de24d872ca7023ced0a and linux Documentation/x86/protection-keys.txt
* remove or1k version of sem.hBobby Bingham2016-07-061-11/+0
| | | | | It's identical to the generic version, after evaluating the endian preprocessor checks in the generic version.
* add preadv2 and pwritev2 syscall numbers for linux v4.6Szabolcs Nagy2016-06-091-0/+2
| | | | | | | | the syscalls take an additional flag argument, they were added in commit f17d8b35452cab31a70d224964cd583fb2845449 and a RWF_HIPRI priority hint flag was added to linux/fs.h in 97be7ebe53915af504fb491fb99f064c7cf3cb09. the syscall is not allocated for microblaze and sh yet.
* deduplicate __NR_* and SYS_* syscall number definitionsBobby Bingham2016-05-122-543/+272
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* add copy_file_range syscall numbers from linux v4.5Szabolcs Nagy2016-03-191-0/+2
| | | | | | | it was introduced for offloading copying between regular files in linux commit 29732938a6289a15e907da234d6692a2ead71855 (microblaze and sh does not yet have the syscall number.)
* deduplicate bits/mman.hSzabolcs Nagy2016-03-181-59/+0
| | | | | | | | | | | currently five targets use the same mman.h constants and the rest share most constants too, so move them to sys/mman.h before the bits/mman.h include where the differences can be corrected by redefinition of the macros. this fixes two minor bugs: POSIX_MADV_DONTNEED was wrong on most targets (it should be the same as MADV_DONTNEED), and sh defined the x86-only MAP_32BIT mmap flag.
* deduplicate the bulk of the arch bits headersRich Felker2016-01-2712-593/+0
| | | | | | | | | | | | all bits headers that were identical for a number of 'clean' archs are moved to the new arch/generic tree. in addition, a few headers that differed only cosmetically from the new generic version are removed. additional deduplication may be possible in mman.h and in several headers (limits.h, posix.h, stdint.h) that mostly depend on whether the arch is 32- or 64-bit, but they are left alone for now because greater gains are likely possible with more invasive changes to header logic, which is beyond the scope of this commit.
* add MCL_ONFAULT and MLOCK_ONFAULT mlockall and mlock2 flagsSzabolcs Nagy2016-01-261-0/+1
| | | | | | | | they lock faulted pages into memory (useful when a small part of a large mapped file needs efficient access), new in linux v4.4, commit b0f205c2a3082dd9081f9a94e50658c5fa906ff1 MLOCK_* is not in the POSIX reserved namespace for sys/mman.h
* add mlock2 syscall number from linux v4.4Szabolcs Nagy2016-01-261-0/+2
| | | | | | | this is mlock with a flags argument, new in linux commit a8ca5d0ecbdde5cc3d7accacbd69968b0c98764e as usual microblaze and sh don't have allocated syscall number yet.
* add new membarrier, userfaultfd and switch_endian syscallsSzabolcs Nagy2016-01-261-0/+4
| | | | | | | | | | | | | | | new in linux v4.3 added for aarch64, arm, i386, mips, or1k, powerpc, x32 and x86_64. membarrier is a system wide memory barrier, moves most of the synchronization cost to one side, new in kernel commit 5b25b13ab08f616efd566347d809b4ece54570d1 userfaultfd is useful for qemu and is new in kernel commit 8d2afd96c20316d112e04d935d9e09150e988397 switch_endian is powerpc only for switching endianness, new in commit 529d235a0e190ded1d21ccc80a73e625ebcad09b
* refactor internal atomic.hRich Felker2016-01-212-120/+14
| | | | | | | | | | | | | | | rather than having each arch provide its own atomic.h, there is a new shared atomic.h in src/internal which pulls arch-specific definitions from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal, defining only a_cas or new ll/sc type primitives which the shared atomic.h will use to construct everything else. this commit avoids making heavy changes to the individual archs' atomic implementations. definitions which are identical or near-identical to what the new shared atomic.h would produce have been removed, but otherwise the changes made are just hooking up the arch-specific files to the new infrastructure. major changes to take advantage of the new system will come in subsequent commits.
* properly access mcontext_t program counter in cancellation handlerRich Felker2015-11-021-2/+1
| | | | | | | | | using the actual mcontext_t definition rather than an overlaid pointer array both improves correctness/readability and eliminates some ugly hacks for archs with 64-bit registers bit 32-bit program counter. also fix UB due to comparison of pointers not in a common array object.
* prevent reordering of or1k and powerpc thread pointer loadsRich Felker2015-10-151-0/+1
| | | | | | | | | | | | | | | | | other archs use asm for the thread pointer load, so making that asm volatile is sufficient to inform the compiler that it has a "side effect" (crashing or giving the wrong result if the thread pointer was not yet initialized) that prevents reordering. however, powerpc and or1k have dedicated general purpose registers for the thread pointer and did not need to use any asm to access it; instead, "local register variables with a specified register" were used. however, there is no specification for ordering constraints on this type of usage, and presumably use of the thread pointer could be reordered across its initialization. to impose an ordering, I have added empty volatile asm blocks that produce the "local register variable with a specified register" as an output constraint.
* new dlstart stage-2 chaining for or1kRich Felker2015-09-171-0/+9
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* add .text section directive to all crt_arch.h files missing itRich Felker2015-05-221-0/+1
| | | | | | | | i386 and x86_64 versions already had the .text directive; other archs did not. normally, top-level (file scope) __asm__ starts in the .text section anyway, but problems were reported with some versions of clang, and it seems preferable to set it explicitly anyway, at least for the sake of consistency between archs.
* fix __syscall declaration with wrong visibility in syscall_arch.hSzabolcs Nagy2015-04-301-2/+0
| | | | | remove __syscall declaration where it is not needed (aarch64, arm, microblaze, or1k) and add the hidden attribute where it is (mips).
* dynamic linker bootstrap overhaulRich Felker2015-04-132-54/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this overhaul further reduces the amount of arch-specific code needed by the dynamic linker and removes a number of assumptions, including: - that symbolic function references inside libc are bound at link time via the linker option -Bsymbolic-functions. - that libc functions used by the dynamic linker do not require access to data symbols. - that static/internal function calls and data accesses can be made without performing any relocations, or that arch-specific startup code handled any such relocations needed. removing these assumptions paves the way for allowing libc.so itself to be built with stack protector (among other things), and is achieved by a three-stage bootstrap process: 1. relative relocations are processed with a flat function. 2. symbolic relocations are processed with no external calls/data. 3. main program and dependency libs are processed with a fully-functional libc/ldso. reduction in arch-specific code is achived through the following: - crt_arch.h, used for generating crt1.o, now provides the entry point for the dynamic linker too. - asm is no longer responsible for skipping the beginning of argv[] when ldso is invoked as a command. - the functionality previously provided by __reloc_self for heavily GOT-dependent RISC archs is now the arch-agnostic stage-1. - arch-specific relocation type codes are mapped directly as macros rather than via an inline translation function/switch statement.
* move O_PATH definition back to arch bitsRich Felker2015-04-011-0/+1
| | | | | | | while it's the same for all presently supported archs, it differs at least on sparc, and conceptually it's no less arch-specific than the other O_* macros. O_SEARCH and O_EXEC are still defined in terms of O_PATH in the main fcntl.h.
* fix MINSIGSTKSZ values for archs with large signal contextsRich Felker2015-03-181-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | the previous values (2k min and 8k default) were too small for some archs. aarch64 reserves 4k in the signal context for future extensions and requires about 4.5k total, and powerpc reportedly uses over 2k. the new minimums are chosen to fit the saved context and also allow a minimal signal handler to run. since the default (SIGSTKSZ) has always been 6k larger than the minimum, it is also increased to maintain the 6k usable by the signal handler. this happens to be able to store one pathname buffer and should be sufficient for calling any function in libc that doesn't involve conversion between floating point and decimal representations. x86 (both 32-bit and 64-bit variants) may also need a larger minimum (around 2.5k) in the future to support avx-512, but the values on these archs are left alone for now pending further analysis. the value for PTHREAD_STACK_MIN is not increased to match MINSIGSTKSZ at this time. this is so as not to preclude applications from using extremely small thread stacks when they know they will not be handling signals. unfortunately cancellation and multi-threaded set*id() use signals as an implementation detail and therefore require a stack large enough for a signal context, so applications which use extremely small thread stacks may still need to avoid using these features.
* fix FLT_ROUNDS to reflect the current rounding modeSzabolcs Nagy2015-03-071-1/+0
| | | | | Implemented as a wrapper around fegetround introducing a new function to the ABI: __flt_rounds. (fegetround cannot be used directly from float.h)
* fix POLLWRNORM and POLLWRBAND on mipsTrutz Behn2015-03-041-0/+0
| | | | | | these macros have the same distinct definition on blackfin, frv, m68k, mips, sparc and xtensa kernels. POLLMSG and POLLRDHUP additionally differ on sparc.
* make all objects used with atomic operations volatileRich Felker2015-03-031-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the memory model we use internally for atomics permits plain loads of values which may be subject to concurrent modification without requiring that a special load function be used. since a compiler is free to make transformations that alter the number of loads or the way in which loads are performed, the compiler is theoretically free to break this usage. the most obvious concern is with atomic cas constructs: something of the form tmp=*p;a_cas(p,tmp,f(tmp)); could be transformed to a_cas(p,*p,f(*p)); where the latter is intended to show multiple loads of *p whose resulting values might fail to be equal; this would break the atomicity of the whole operation. but even more fundamental breakage is possible. with the changes being made now, objects that may be modified by atomics are modeled as volatile, and the atomic operations performed on them by other threads are modeled as asynchronous stores by hardware which happens to be acting on the request of another thread. such modeling of course does not itself address memory synchronization between cores/cpus, but that aspect was already handled. this all seems less than ideal, but it's the best we can do without mandating a C11 compiler and using the C11 model for atomics. in the case of pthread_once_t, the ABI type of the underlying object is not volatile-qualified. so we are assuming that accessing the object through a volatile-qualified lvalue via casts yields volatile access semantics. the language of the C standard is somewhat unclear on this matter, but this is an assumption the linux kernel also makes, and seems to be the correct interpretation of the standard.
* add syscall numbers for the new execveat syscallSzabolcs Nagy2015-02-091-0/+2
| | | | | | | | | this syscall allows fexecve to be implemented without /proc, it is new in linux v3.19, added in commit 51f39a1f0cea1cacf8c787f652f26dfee9611874 (sh and microblaze do not have allocated syscall numbers yet) added a x32 fix as well: the io_setup and io_submit syscalls are no longer common with x86_64, so use the x32 specific numbers.
* move MREMAP_MAYMOVE and MREMAP_FIXED out of bitsTrutz Behn2015-01-301-3/+0
| | | | | | the definitions are generic for all kernel archs. exposure of these macros now only occurs on the same feature test as for the function accepting them, which is believed to be more correct.
* add new syscall numbers for bpf and kexec_file_loadSzabolcs Nagy2014-12-231-0/+2
| | | | | | | | | | | these syscalls are new in linux v3.18, bpf is present on all supported archs except sh, kexec_file_load is only allocted for x86_64 and x32 yet. bpf was added in linux commit 99c55f7d47c0dc6fc64729f37bf435abf43f4c60 kexec_file_load syscall number was allocated in commit f0895685c7fd8c938c91a9d8a6f7c11f22df58d2
* move wint_t definition to the shared part of alltypes.h.inRich Felker2014-12-211-1/+0
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* unify non-inline version of syscall code across archsRich Felker2014-11-221-34/+2
| | | | | | | | | | | | | | except powerpc, which still lacks inline syscalls simply because nobody has written the code, these are all fallbacks used to work around a clang bug that probably does not exist in versions of clang that can compile musl. however, it's useful to have the generic non-inline code anyway, as it eases the task of porting to new archs: writing inline syscall code is now optional. this approach could also help support compilers which don't understand inline asm or lack support for the needed register constraints. mips could not be unified because it has special fixup code for broken layout of the kernel's struct stat.
* fix 64-bit syscall argument passing on or1kRich Felker2014-11-051-1/+1
| | | | | | the kernel syscall interface for or1k does not expect 64-bit arguments to be aligned to "even" register boundaries. this incorrect alignment broke truncate/ftruncate and as well as a few less-common syscalls.
* add explicit barrier operation to internal atomic.h APIRich Felker2014-10-101-1/+3
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* add new syscall numbers for seccomp, getrandom, memfd_createSzabolcs Nagy2014-10-081-0/+6
| | | | | | | | | | | | | | | | | | these syscalls are new in linux v3.17 and present on all supported archs except sh. seccomp was added in commit 48dc92b9fc3926844257316e75ba11eb5c742b2c it has operation, flags and pointer arguments (if flags==0 then it is the same as prctl(PR_SET_SECCOMP,...)), the uapi header for flag definitions is linux/seccomp.h getrandom was added in commit c6e9d6f38894798696f23c8084ca7edbf16ee895 it provides an entropy source when open("/dev/urandom",..) would fail, the uapi header for flags is linux/random.h memfd_create was added in commit 9183df25fe7b194563db3fec6dc3202a5855839c it allows anon mmap to have an fd, that can be shared, sealed and needs no mount point, the uapi header for flags is linux/memfd.h
* add threads.h and needed per-arch types for mtx_t and cnd_tRich Felker2014-09-061-0/+2
| | | | | | | | | | | | | | | | based on patch by Jens Gustedt. mtx_t and cnd_t are defined in such a way that they are formally "compatible types" with pthread_mutex_t and pthread_cond_t, respectively, when accessed from a different translation unit. this makes it possible to implement the C11 functions using the pthread functions (which will dereference them with the pthread types) without having to use the same types, which would necessitate either namespace violations (exposing pthread type names in threads.h) or incompatible changes to the C++ name mangling ABI for the pthread types. for the rest of the types, things are much simpler; using identical types is possible without any namespace considerations.
* add working a_spin() atomic for non-x86 targetsRich Felker2014-08-251-0/+1
| | | | | | | | | | | | | conceptually, a_spin needs to be at least a compiler barrier, so the compiler will not optimize out loops (and the load on each iteration) while spinning. it should also be a memory barrier, or the spinning thread might keep spinning without noticing stores from other threads, thus delaying for longer than it should. ideally, an optimal a_spin implementation that avoids unnecessary cache/memory contention should be chosen for each arch, but for now, the easiest thing is to perform a useless a_cas on the calling thread's stack.
* add max_align_t definition for C11 and C++11Rich Felker2014-08-201-0/+2
| | | | | | | | | | | | | | | | | unfortunately this needs to be able to vary by arch, because of a huge mess GCC made: the GCC definition, which became the ABI, depends on quirks in GCC's definition of __alignof__, which does not match the formal alignment of the type. GCC's __alignof__ unexpectedly exposes the an implementation detail, its "preferred alignment" for the type, rather than the formal/ABI alignment of the type, which it only actually uses in structures. on most archs the two values are the same, but on some (at least i386) the preferred alignment is greater than the ABI alignment. I considered using _Alignas(8) unconditionally, but on at least one arch (or1k), the alignment of max_align_t with GCC's definition is only 4 (even the "preferred alignment" for these types is only 4).
* make pointers used in robust list volatileRich Felker2014-08-171-1/+1
| | | | | | | | | | | | | | | | | | | | when manipulating the robust list, the order of stores matters, because the code may be asynchronously interrupted by a fatal signal and the kernel will then access the robust list in what is essentially an async-signal context. previously, aliasing considerations made it seem unlikely that a compiler could reorder the stores, but proving that they could not be reordered incorrectly would have been extremely difficult. instead I've opted to make all the pointers used as part of the robust list, including those in the robust list head and in the individual mutexes, volatile. in addition, the format of the robust list has been changed to point back to the head at the end, rather than ending with a null pointer. this is to match the documented kernel robust list ABI. the null pointer, which was previously used, only worked because faults during access terminate the robust list processing.
* fix broken offset argument to the mmap2 syscall on or1kRich Felker2014-07-301-0/+2
| | | | | | for or1k, the kernel expects the offset passed to mmap2 in units of the 8k page size, not the standard unit of 4k used on most other archs.
* provide PAGE_SIZE as a constant value of 8192 on or1kRich Felker2014-07-301-0/+1
| | | | | according to Stefan Kristiansson, or1k page size is not actually variable and the value of 8192 is part of the ABI.
* remove unused a_cas_l from or1k atomic.hRich Felker2014-07-271-5/+0
| | | | this follows the same logic as in the previous commit for other archs.
* add syscall numbers for the new renameat2 syscallSzabolcs Nagy2014-07-201-0/+6
| | | | | it's like rename but with flags eg. to allow atomic exchange of two files, introduced in linux 3.15 commit 520c8b16505236fc82daa352e6c5e73cd9870cff
* fix or1k atomic storeRich Felker2014-07-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | at the very least, a compiler barrier is required no matter what, and that was missing. current or1k implementations have strong ordering, but this is not guaranteed as part of the ISA, so some sort of synchronizing operation is necessary. in principle we should use l.msync, but due to misinterpretation of the spec, it was wrongly treated as an optional instruction and is not supported by some implementations. if future kernels trap it and treat it as a nop (rather than illegal instruction) when the hardware/emulator does not support it, we could consider using it. in the absence of l.msync support, the l.lwa/l.swa instructions, which are specified to have a built-in l.msync, need to be used. the easiest way to use them to implement atomic store is to perform an atomic swap and throw away the result. using compare-and-swap would be lighter, and would probably be sufficient for all actual usage cases, but checking this is difficult and error-prone: with store implemented in terms of swap, it's guaranteed that, when another atomic operation is performed at the same time as the store, either the result of the store followed by the other operation, or just the store (clobbering the other operation's result) is seen. if store were implemented in terms of cas, there are cases where this invariant would fail to hold, and we would need detailed rules for the situations in which the store operation is well-defined.
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