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author | Rich Felker <dalias@aerifal.cx> | 2023-03-03 09:27:04 -0500 |
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committer | Rich Felker <dalias@aerifal.cx> | 2023-03-03 09:52:52 -0500 |
commit | b6811019e62a7561a4922f90e54b30ac306efe0b (patch) | |
tree | 964cd15c4e8fa86497b8b52d79fa00ef5c1e17ad /src | |
parent | 8949da7ab1c0dbf801e8bc78f0c0adc625020f75 (diff) | |
download | musl-b6811019e62a7561a4922f90e54b30ac306efe0b.tar.gz musl-b6811019e62a7561a4922f90e54b30ac306efe0b.tar.bz2 musl-b6811019e62a7561a4922f90e54b30ac306efe0b.tar.xz musl-b6811019e62a7561a4922f90e54b30ac306efe0b.zip |
poll: fix misuse of timespec type on 32-bit archs without poll syscall
this function was overlooked during the time64 transition, probably as
a result of not having any time-related types in its application-side
interface. however, for archs that lack the traditional poll syscall
and have only ppoll, it used timespec as part of its interface with
the kernel: the millisecond timeout was converted to a timespec to
pass to SYS_ppoll. this is a type/ABI mismatch on 32-bit archs with
legacy time32 syscalls.
only one supported arch, or1k, is affected. all of the others either
have SYS_poll, or are 64-bit.
rather than using timespec, define a type locally to match what the
kernel expects. the condition (SYS_ppoll_time64 == SYS_ppoll),
comparable to conditions used elsewhere in timespec-handling code,
evaluates true for "natively time64" 32-bit archs including x32,
future riscv32, and all future 32-bit archs (via definitions in
internal syscall.h). otherwise, the arch is either 64-bit or has
syscalls that take the legacy type, and in either case "long" is
correct.
this fix is based on bug report and proposal by Alexey Izbyshev but
with a different approach to the changes to minimize the contextual
knowledge needed for a reader to understand the source file.
Diffstat (limited to 'src')
-rw-r--r-- | src/select/poll.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/select/poll.c b/src/select/poll.c index c84c8a99..7883dfab 100644 --- a/src/select/poll.c +++ b/src/select/poll.c @@ -8,8 +8,13 @@ int poll(struct pollfd *fds, nfds_t n, int timeout) #ifdef SYS_poll return syscall_cp(SYS_poll, fds, n, timeout); #else +#if SYS_ppoll_time64 == SYS_ppoll + typedef long long ppoll_ts_t[2]; +#else + typedef long ppoll_ts_t[2]; +#endif return syscall_cp(SYS_ppoll, fds, n, timeout>=0 ? - &((struct timespec){ .tv_sec = timeout/1000, - .tv_nsec = timeout%1000*1000000 }) : 0, 0, _NSIG/8); + ((ppoll_ts_t){ timeout/1000, timeout%1000*1000000 }) : 0, + 0, _NSIG/8); #endif } |