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authorRichard Henderson <richard.henderson@linaro.org>2019-03-13 20:47:32 -0700
committerRichard Henderson <richard.henderson@linaro.org>2019-05-22 12:38:54 -0400
commit25fb26e4f4b7cd50b9a7314400a2f800a4082b71 (patch)
tree294e9e3735a2f0a34f05b9ce877ad6ae3e2432f2 /crypto
parent14a356f47560c8275b8e04fbee484a617fc45f80 (diff)
crypto: Do not fail for EINTR during qcrypto_random_bytes
We can always get EINTR for read; /dev/urandom is no exception. Rearrange the order of tests for likelihood; allow degenerate buflen==0 case to perform a no-op zero-length read. This means that the normal success path is a straight line with a single test for success. Reviewed-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/random-platform.c36
1 files changed, 15 insertions, 21 deletions
diff --git a/crypto/random-platform.c b/crypto/random-platform.c
index f995fc0ef1..260b64564d 100644
--- a/crypto/random-platform.c
+++ b/crypto/random-platform.c
@@ -65,29 +65,23 @@ 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;
+ while (1) {
+ ssize_t got = read(fd, buf, buflen);
+ if (likely(got == buflen)) {
+ return 0;
+ }
+ if (got > 0) {
+ buflen -= got;
+ buf += got;
+ } else 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;
}
- buflen -= got;
- buf += got;
}
-
- ret = 0;
- cleanup:
- return ret;
#endif
+ return 0;
}