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[97.113.188.82]) by smtp.gmail.com with ESMTPSA id d26sm690816pfn.86.2019.03.14.20.26.34 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 14 Mar 2019 20:26:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=3rnkQV2mDwDjm+peqMAHfkM55fLPgrlpN1xVPWcrulw=; b=UA98FuJ1Vkv5VA/8SatuiOvrtXjTFk3tIiR8NTSiNwHQhKrev91IJpYBABGQvqd8LR +sURLTvbXl7yzMOd9KeHBY45Xd5oabadEzV9LS9Z9YfUcEtJvFGjTzNBGGnOsg6Isgjo TXF8hcgd+klBGcNdaZmoTRrQE7/cOLh3pilLtwYk2R+Z5ez0H2rHx83i4icSNbFN9Dgg t+/8k2Vxw3gPC9014wGPLZPB2U+m1qPHZ0r6nvEcK32q3EZACunssswZJVxa6ZVTCcnY p6sDzyI8IFGTR/2G5D+OM1mpsJuWFKv7NbVMrNrIgW6nuRBhDpzDCYFMIZfVjiyJwqdB um9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=3rnkQV2mDwDjm+peqMAHfkM55fLPgrlpN1xVPWcrulw=; b=cLXSDz7XvcmFQczF2Y1MM+jA9PxxY2twDP7bYNO71c8RYnfc1e1M+dtdFvTbqa0tIo mlAqLYQF1OAozmCLq4D/GFs75R1JZnF9XIlxlngBAfqu3nN+8stlNkKoFGZb8/XXljAp GJtj4B9W/pzxr/hWG7DcloMjrJqge5gPM3pCV7kxxWi/xaTgIKxjyrWUdJdIi9gDxkDP iaKcejtH9Yv0140tY+afPfA4bsPp77Jn2/qsKSAJhy3BMKEFvsXQlFhNw35CQ3hkMh0N mjAsweSXygYwRkFcWUF8AbNPBjIrM9KlNTZ7AvRqhmnnP1vn9NkW94Y21e6jL/piNSNR +xCg== X-Gm-Message-State: APjAAAWLB320OA5P/5eQLJYdq94HrIoLVnDl/IvpDr/KEXczICpIezYc yJhfIgb5Coe3GHa4R3QuxHpSCvmIx6s= X-Google-Smtp-Source: APXvYqyQ+ksOjYXcZ72YlqM9l4Om5VzRN4Q/PEDBcH/XVUTj+hZeah+6oD5OtSL9TJ0gYT98a9W+Sw== X-Received: by 2002:a17:902:b188:: with SMTP id s8mr1720020plr.327.1552620395603; Thu, 14 Mar 2019 20:26:35 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Date: Thu, 14 Mar 2019 20:26:09 -0700 Message-Id: <20190315032629.21234-4-richard.henderson@linaro.org> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190315032629.21234-1-richard.henderson@linaro.org> References: <20190315032629.21234-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::441 Subject: [Qemu-devel] [PATCH v3 03/23] crypto: Do not fail for EINTR during qcrypto_random_bytes X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) We can always get EINTR for read; /dev/urandom is no exception. Rearrange the order of tests for likelihood; allow degenerate buflen=3D=3D0 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: Daniel P. Berrang=C3=A9 Signed-off-by: Richard Henderson --- v3: Rearrage the read loop again. --- crypto/random-platform.c | 36 +++++++++++++++--------------------- 1 file 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 =3D -1; - int got; - - while (buflen > 0) { - got =3D 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 =3D read(fd, buf, buflen); + if (likely(got =3D=3D buflen)) { + return 0; + } + if (got > 0) { + buflen -=3D got; + buf +=3D got; + } else if (got =3D=3D 0) { + error_setg(errp, "Unexpected EOF reading random bytes"); + return -1; + } else if (errno !=3D EINTR) { + error_setg_errno(errp, errno, "Unable to read random bytes"); + return -1; } - buflen -=3D got; - buf +=3D got; } - - ret =3D 0; - cleanup: - return ret; #endif + return 0; } --=20 2.17.2