mirror of
git://git.musl-libc.org/musl
synced 2024-12-16 03:35:06 +00:00
40aa18d55a
x32 is odd in that it's the only ILP32 arch/ABI we have where time_t is 64-bit rather than (32-bit) long, and this has always been problematic in that it results in struct timespec having unused padding space, since tv_nsec has type long, which the kernel insists be zero- or sign-extended (due to negative tv_nsec being invalid, it doesn't matter which) to match the x86_64 type. up til now, we've had really ugly hacks in x32/syscall_arch.h to patch up the timespecs passed to the kernel. but the same requirement to zero- or sign-extend tv_nsec also applies to all the new time64 syscalls on true 32-bit archs. so let's take advantage of this to clean things up. this patch defines all of the time64 syscalls for x32 as aliases for the existing syscalls by the same name. this establishes the following invariants: - if the time64 form is defined, it takes time arguments as 64-bit objects, and tv_nsec inputs must be zero-/sign-extended to 64-bit. - if the time64 form is not defined, or if the time64 form is defined and is not equal to the "plain" form, the plain form takes time arguments as longs. this will avoid the need for protocols for archs to define appropriate types for each family of syscalls, and for the reader of the code to have to be aware of such type definitions. in some sense it might be simpler if the plain syscall form were undefined for x32, so that it would always take longs if defined. however, a number of these syscalls are used in contexts with a null time argument, or (e.g. futex) for commands that don't involve time at all, and having to introduce time64-specific logic to all those call points does not make sense. thus, while the "plain" forms are kept now just because they're needed until the affected code is converted over, they'll also almost surely be kept in the future as well. |
||
|---|---|---|
| .. | ||
| aarch64 | ||
| arm | ||
| generic | ||
| i386 | ||
| m68k | ||
| microblaze | ||
| mips | ||
| mips64 | ||
| mipsn32 | ||
| or1k | ||
| powerpc | ||
| powerpc64 | ||
| riscv64 | ||
| s390x | ||
| sh | ||
| x32 | ||
| x86_64 | ||