On 2/5/19 2:22 PM, Peter Maydell wrote: > On Tue, 29 Jan 2019 at 17:59, Philippe Mathieu-Daudé <[email protected]> > wrote: >> >> Previous to OpenBSD 6.3 [1], fcntl(F_SETFL) is not permitted on >> memory devices. >> Trying this call sets errno to ENODEV ("not a memory device"): >> >> 19 ENODEV Operation not supported by device. >> An attempt was made to apply an inappropriate function to a device, >> for example, trying to read a write-only device such as a printer. >> >> Do not assert fcntl failures in this specific case (errno set to ENODEV) >> on OpenBSD. This fixes: >> >> $ lm32-softmmu/qemu-system-lm32 >> assertion "f != -1" failed: file "util/oslib-posix.c", line 247, function >> "qemu_set_nonblock" >> Abort trap (core dumped) >> >> [1] The fix seems https://github.com/openbsd/src/commit/c2a35b387f9d3c >> "fcntl(F_SETFL) invokes the FIONBIO and FIOASYNC ioctls internally, so >> the memory devices (/dev/null, /dev/zero, etc) need to permit them." >> >> Signed-off-by: Philippe Mathieu-Daudé <[email protected]> >> --- >> util/oslib-posix.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/util/oslib-posix.c b/util/oslib-posix.c >> index 4ce1ba9ca4..2f0f27e6d9 100644 >> --- a/util/oslib-posix.c >> +++ b/util/oslib-posix.c >> @@ -244,7 +244,17 @@ void qemu_set_nonblock(int fd) >> f = fcntl(fd, F_GETFL); >> assert(f != -1); >> f = fcntl(fd, F_SETFL, f | O_NONBLOCK); >> +#ifdef __OpenBSD__ >> + if (f == -1) { >> + /* >> + * Previous to OpenBSD 6.3, fcntl(F_SETFL) is not permitted on >> + * memory devices and sets errno to ENODEV. >> + */ >> + assert(errno == ENODEV); >> + } >> +#else >> assert(f != -1); >> +#endif > > You might also add "It's OK if we fail to set O_NONBLOCK on devices > like /dev/null, because they will never block anyway."
OK! > Reviewed-by: Peter Maydell <[email protected]> Thanks for reviewing this series :) > > thanks > -- PMM >
