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[198.145.21.10]) by mx.google.com with ESMTPS id b14si8867105plk.487.2017.11.05.08.53.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 05 Nov 2017 08:53:06 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 198.145.21.10 as permitted sender) client-ip=198.145.21.10; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org header.s=google header.b=cCZBIIrv; spf=pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 198.145.21.10 as permitted sender) smtp.mailfrom=edk2-devel-bounces@lists.01.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 4EB102034AB0D; Sun, 5 Nov 2017 08:49:07 -0800 (PST) X-Original-To: edk2-devel@lists.01.org Delivered-To: edk2-devel@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2a00:1450:400c:c09::236; helo=mail-wm0-x236.google.com; envelope-from=ard.biesheuvel@linaro.org; receiver=edk2-devel@lists.01.org Received: from mail-wm0-x236.google.com (mail-wm0-x236.google.com [IPv6:2a00:1450:400c:c09::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id DA7CB2034EE34 for ; Sun, 5 Nov 2017 08:49:05 -0800 (PST) Received: by mail-wm0-x236.google.com with SMTP id t139so9908006wmt.1 for ; Sun, 05 Nov 2017 08:53:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=1Tun/BFm59uMtloYELrAquFHXqLMavMFtCvmJicCu08=; b=cCZBIIrvVx1lBScfFftYlChaRmW2rCrlWLQtU1urhiZccppGNbpTw1nUosJpYqaUhM mqhP3Qs0uj0BV9T+/zXvGRnO7Eom7S21nyKltOC6b4mcXWT5T9htXWGwml+XNCaotuzE 3EPykZdTuJ8Mdo6o47o05TyKBEKEmCRCepTaI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=1Tun/BFm59uMtloYELrAquFHXqLMavMFtCvmJicCu08=; b=WO5DDs9uXxX8oRltQHUIUQxG0Gxe7bfTc6GM4kmMeqV3ar/l4sBVGY92Th80YCDmsq tHyvH8oU9C6QvPBS3wOocUAYIP5W2YG4uWUpzn9BSHZ1NNEWpP4D86D6t2/j4PbFiOZ3 23oDctpvLb2zqmE+I3Hon35QwU2e/jshjYK2gAfkc0Li3XpClkrYhjLP2J9cnZLsCSIV KXVOaK1CJIaP3+AhCNBzGvHe3kpmQKM9JrqvaLaGYYN9A6j4f24ySxLflyfqqtmIhX4D GPlyihhDiH0COtSDMtSrkJ7tJWxsejNwTWOLo/OtFZ+42PbyExZTgpHVWq26vTBnLqxv nPeg== X-Gm-Message-State: AJaThX75mPWl6j94i+RVyp9xmx/1hTRr+IkKvx+3M1wzHBSDRNJt8Z2q fdEGl9ZIAIAaJN3eIrXbZmfOoive9XA= X-Received: by 10.28.160.21 with SMTP id j21mr1628939wme.15.1509900781103; Sun, 05 Nov 2017 08:53:01 -0800 (PST) Received: from localhost.localdomain ([105.129.222.2]) by smtp.gmail.com with ESMTPSA id 141sm8835247wmr.45.2017.11.05.08.52.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 05 Nov 2017 08:53:00 -0800 (PST) From: Ard Biesheuvel To: edk2-devel@lists.01.org, leif.lindholm@linaro.org Date: Sun, 5 Nov 2017 16:52:53 +0000 Message-Id: <20171105165253.32571-2-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171105165253.32571-1-ard.biesheuvel@linaro.org> References: <20171105165253.32571-1-ard.biesheuvel@linaro.org> Subject: [edk2] [PATCH 2/2] ArmPlatformPkg/PL031RealTimeClockLib: remove validation and DST handling X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ard Biesheuvel MIME-Version: 1.0 Errors-To: edk2-devel-bounces@lists.01.org Sender: "edk2-devel" This library, which is intended to encapsulate the hardware specifics of the ARM PL031 RTC, also implements its own input validation routines, and even makes a feeble attempt at timezone and DST handling. The input validation belongs in the core driver, and has been introduced there, so we can remove it. As for the DST handling, this code is simply wrong, and the UEFI spec's definition of EFI_TIME simply does not carry enough information to convert a UNIX timestamp (seconds since 1/1/1970) into a local time value. The EFI_TIME_ADJUST_DAYLIGHT/EFI_TIME_IN_DAYLIGHT flags we do have only tell us whether our clock is adjusted back and forth for DST, and whether it is currently set to DST or not. What the PL031 driver attempts to do is convert the UNIX timestamp to a local time, by adding the timezone offset (which is fair), but it also adds an hour if the EFI_TIME_IN_DAYLIGHT is set. However, that flag does not imply that DST is currently in effect, it only implies that the clock is running an hour ahead of its standard time, and the UEFI spec leaves it up to the OS to update the clock when necessary. To really perform this conversion correctly, we lack sufficient information about the timezone: our timezone setting is defined as minutes ahead or behind UTC, but many different DST regimes may be in effect in the same geographical (i.e., longitude based) timezone, including ones where the clock moves back and forth twice a year. So let's remove all of it, and rely on the core driver to record the timezone and DST flags, and treat them as informational only (as the spec intends) Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel --- ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c | 194 +------------------- 1 file changed, 8 insertions(+), 186 deletions(-) -- 2.11.0 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel diff --git a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c index 41ebcb95ab85..e0d90f853fca 100644 --- a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c +++ b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c @@ -40,8 +40,6 @@ #include -STATIC CONST CHAR16 mTimeZoneVariableName[] = L"PL031RtcTimeZone"; -STATIC CONST CHAR16 mDaylightVariableName[] = L"PL031RtcDaylight"; STATIC BOOLEAN mPL031Initialized = FALSE; STATIC EFI_EVENT mRtcVirtualAddrChangeEvent; STATIC UINTN mPL031RtcBase; @@ -134,15 +132,12 @@ LibGetTime ( { EFI_STATUS Status = EFI_SUCCESS; UINT32 EpochSeconds; - INT16 TimeZone; - UINT8 Daylight; - UINTN Size; // Initialize the hardware if not already done if (!mPL031Initialized) { Status = InitializePL031 (); if (EFI_ERROR (Status)) { - goto EXIT; + return Status; } } @@ -156,7 +151,7 @@ LibGetTime ( Status = EFI_SUCCESS; } else if (EFI_ERROR (Status)) { // Battery backed up hardware RTC exists but could not be read due to error. Abort. - goto EXIT; + return Status; } else { // Battery backed up hardware RTC exists and we read the time correctly from it. // Now sync the PL031 to the new time. @@ -165,107 +160,7 @@ LibGetTime ( // Ensure Time is a valid pointer if (Time == NULL) { - Status = EFI_INVALID_PARAMETER; - goto EXIT; - } - - // Get the current time zone information from non-volatile storage - Size = sizeof (TimeZone); - Status = EfiGetVariable ( - (CHAR16 *)mTimeZoneVariableName, - &gEfiCallerIdGuid, - NULL, - &Size, - (VOID *)&TimeZone - ); - - if (EFI_ERROR (Status)) { - ASSERT(Status != EFI_INVALID_PARAMETER); - ASSERT(Status != EFI_BUFFER_TOO_SMALL); - - if (Status != EFI_NOT_FOUND) - goto EXIT; - - // The time zone variable does not exist in non-volatile storage, so create it. - Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE; - // Store it - Status = EfiSetVariable ( - (CHAR16 *)mTimeZoneVariableName, - &gEfiCallerIdGuid, - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, - Size, - (VOID *)&(Time->TimeZone) - ); - if (EFI_ERROR (Status)) { - DEBUG (( - EFI_D_ERROR, - "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n", - mTimeZoneVariableName, - Status - )); - goto EXIT; - } - } else { - // Got the time zone - Time->TimeZone = TimeZone; - - // Check TimeZone bounds: -1440 to 1440 or 2047 - if (((Time->TimeZone < -1440) || (Time->TimeZone > 1440)) - && (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE)) { - Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE; - } - - // Adjust for the correct time zone - if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) { - EpochSeconds += Time->TimeZone * SEC_PER_MIN; - } - } - - // Get the current daylight information from non-volatile storage - Size = sizeof (Daylight); - Status = EfiGetVariable ( - (CHAR16 *)mDaylightVariableName, - &gEfiCallerIdGuid, - NULL, - &Size, - (VOID *)&Daylight - ); - - if (EFI_ERROR (Status)) { - ASSERT(Status != EFI_INVALID_PARAMETER); - ASSERT(Status != EFI_BUFFER_TOO_SMALL); - - if (Status != EFI_NOT_FOUND) - goto EXIT; - - // The daylight variable does not exist in non-volatile storage, so create it. - Time->Daylight = 0; - // Store it - Status = EfiSetVariable ( - (CHAR16 *)mDaylightVariableName, - &gEfiCallerIdGuid, - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, - Size, - (VOID *)&(Time->Daylight) - ); - if (EFI_ERROR (Status)) { - DEBUG (( - EFI_D_ERROR, - "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n", - mDaylightVariableName, - Status - )); - goto EXIT; - } - } else { - // Got the daylight information - Time->Daylight = Daylight; - - // Adjust for the correct period - if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) { - // Convert to adjusted time, i.e. spring forwards one hour - EpochSeconds += SEC_PER_HOUR; - } + return EFI_INVALID_PARAMETER; } // Convert from internal 32-bit time to UEFI time @@ -281,8 +176,7 @@ LibGetTime ( Capabilities->SetsToZero = FALSE; } - EXIT: - return Status; + return EFI_SUCCESS; } @@ -305,55 +199,24 @@ LibSetTime ( EFI_STATUS Status; UINTN EpochSeconds; - // Check the input parameters are within the range specified by UEFI - if ((Time->Year < 1900) || - (Time->Year > 9999) || - (Time->Month < 1 ) || - (Time->Month > 12 ) || - (!IsDayValid (Time) ) || - (Time->Hour > 23 ) || - (Time->Minute > 59 ) || - (Time->Second > 59 ) || - (Time->Nanosecond > 999999999) || - (!((Time->TimeZone == EFI_UNSPECIFIED_TIMEZONE) || ((Time->TimeZone >= -1440) && (Time->TimeZone <= 1440)))) || - (Time->Daylight & (~(EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT))) - ) { - Status = EFI_INVALID_PARAMETER; - goto EXIT; - } - // Because the PL031 is a 32-bit counter counting seconds, // the maximum time span is just over 136 years. // Time is stored in Unix Epoch format, so it starts in 1970, // Therefore it can not exceed the year 2106. if ((Time->Year < 1970) || (Time->Year >= 2106)) { - Status = EFI_UNSUPPORTED; - goto EXIT; + return EFI_UNSUPPORTED; } // Initialize the hardware if not already done if (!mPL031Initialized) { Status = InitializePL031 (); if (EFI_ERROR (Status)) { - goto EXIT; + return Status; } } EpochSeconds = EfiTimeToEpoch (Time); - // Adjust for the correct time zone, i.e. convert to UTC time zone - if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) { - EpochSeconds -= Time->TimeZone * SEC_PER_MIN; - } - - // TODO: Automatic Daylight activation - - // Adjust for the correct period - if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) { - // Convert to un-adjusted time, i.e. fall back one hour - EpochSeconds -= SEC_PER_HOUR; - } - // On some platforms we may have access to a battery backed up hardware clock. // // If such RTC exists then it must be updated first, before the PL031, @@ -364,54 +227,13 @@ LibSetTime ( Status = ArmPlatformSysConfigSet (SYS_CFG_RTC, EpochSeconds); if ((EFI_ERROR (Status)) && (Status != EFI_UNSUPPORTED)){ // Any status message except SUCCESS and UNSUPPORTED indicates a hardware failure. - goto EXIT; + return Status; } - // Set the PL031 MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds); - // The accesses to Variable Services can be very slow, because we may be writing to Flash. - // Do this after having set the RTC. - - // Save the current time zone information into non-volatile storage - Status = EfiSetVariable ( - (CHAR16 *)mTimeZoneVariableName, - &gEfiCallerIdGuid, - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, - sizeof (Time->TimeZone), - (VOID *)&(Time->TimeZone) - ); - if (EFI_ERROR (Status)) { - DEBUG (( - EFI_D_ERROR, - "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n", - mTimeZoneVariableName, - Status - )); - goto EXIT; - } - - // Save the current daylight information into non-volatile storage - Status = EfiSetVariable ( - (CHAR16 *)mDaylightVariableName, - &gEfiCallerIdGuid, - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, - sizeof(Time->Daylight), - (VOID *)&(Time->Daylight) - ); - if (EFI_ERROR (Status)) { - DEBUG (( - EFI_D_ERROR, - "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n", - mDaylightVariableName, - Status - )); - goto EXIT; - } - - EXIT: - return Status; + return EFI_SUCCESS; }