| Message ID | 20190314045526.13342-4-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Add qemu_getrandom and ARMv8.5-RNG | expand |
On Wed, Mar 13, 2019 at 09:55:15PM -0700, Richard Henderson wrote: > We can always get EINTR for read; /dev/urandom is no exception. > Clean up return paths and avoid unnecessary goto. > > Cc: Daniel P. Berrangé <berrange@redhat.com> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > crypto/random-platform.c | 33 +++++++++++++-------------------- > 1 file changed, 13 insertions(+), 20 deletions(-) > > diff --git a/crypto/random-platform.c b/crypto/random-platform.c > index f995fc0ef1..0866f216dc 100644 > --- a/crypto/random-platform.c > +++ b/crypto/random-platform.c > @@ -65,29 +65,22 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, > "Unable to read random bytes"); > return -1; > } > - > - return 0; > #else > - int ret = -1; > - int got; > - > while (buflen > 0) { > - got = read(fd, buf, buflen); > - if (got < 0) { > - error_setg_errno(errp, errno, > - "Unable to read random bytes"); > - goto cleanup; > - } else if (!got) { > - error_setg(errp, > - "Unexpected EOF reading random bytes"); > - goto cleanup; > + ssize_t got = read(fd, buf, buflen); > + if (unlikely(got <= 0)) { Not seeing a the need for the unlikely() call there - I'd expect any benefit is dwarved by the read syscall time. > + if (got == 0) { > + error_setg(errp, "Unexpected EOF reading random bytes"); > + return -1; > + } else if (errno != EINTR) { > + error_setg_errno(errp, errno, "Unable to read random bytes"); > + return -1; > + } > + } else { > + buflen -= got; > + buf += got; > } > - buflen -= got; > - buf += got; > } > - > - ret = 0; > - cleanup: > - return ret; > #endif > + return 0; > } Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
diff --git a/crypto/random-platform.c b/crypto/random-platform.c index f995fc0ef1..0866f216dc 100644 --- a/crypto/random-platform.c +++ b/crypto/random-platform.c @@ -65,29 +65,22 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, "Unable to read random bytes"); return -1; } - - return 0; #else - int ret = -1; - int got; - while (buflen > 0) { - got = read(fd, buf, buflen); - if (got < 0) { - error_setg_errno(errp, errno, - "Unable to read random bytes"); - goto cleanup; - } else if (!got) { - error_setg(errp, - "Unexpected EOF reading random bytes"); - goto cleanup; + ssize_t got = read(fd, buf, buflen); + if (unlikely(got <= 0)) { + if (got == 0) { + error_setg(errp, "Unexpected EOF reading random bytes"); + return -1; + } else if (errno != EINTR) { + error_setg_errno(errp, errno, "Unable to read random bytes"); + return -1; + } + } else { + buflen -= got; + buf += got; } - buflen -= got; - buf += got; } - - ret = 0; - cleanup: - return ret; #endif + return 0; }
We can always get EINTR for read; /dev/urandom is no exception. Clean up return paths and avoid unnecessary goto. Cc: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- crypto/random-platform.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) -- 2.17.1