From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c In-Reply-To: <1520970688-19683-1-git-send-email-s.mesoraca16@gmail.com> References: <1520970688-19683-1-git-send-email-s.mesoraca16@gmail.com> Date: Wed, 14 Mar 2018 14:17:07 +0200 Message-ID: <87fu52n96k.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain To: Salvatore Mesoraca , linux-kernel@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kernel-hardening@lists.openwall.com, David Airlie , Joonas Lahtinen , Kees Cook , Rodrigo Vivi List-ID: On Tue, 13 Mar 2018, Salvatore Mesoraca wrote: > Avoid 3 VLAs[1] by using real constant expressions instead of variables. > The compiler should be able to optimize the original code and avoid using > any actual VLAs. Anyway this change is useful because it will avoid a false > positives with -Wvla, it might also help the compiler generating better > code. Thanks for your patch. However, Chris beat you to it with: 7aa0b14ede64 ("drm/i915: Remove variable length arrays from sseu debugfs printers") as well as adding -Wvla to our subdir-ccflags-y to prevent more from cropping up: c5c2b11894f4 ("drm/i915: Warn against variable length arrays") BR, Jani. -- Jani Nikula, Intel Open Source Technology Center From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c Date: Wed, 14 Mar 2018 14:17:07 +0200 Message-ID: <87fu52n96k.fsf@intel.com> References: <1520970688-19683-1-git-send-email-s.mesoraca16@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <1520970688-19683-1-git-send-email-s.mesoraca16@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: linux-kernel@vger.kernel.org Cc: Salvatore Mesoraca , Kees Cook , kernel-hardening@lists.openwall.com, David Airlie , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Rodrigo Vivi List-Id: dri-devel@lists.freedesktop.org T24gVHVlLCAxMyBNYXIgMjAxOCwgU2FsdmF0b3JlIE1lc29yYWNhIDxzLm1lc29yYWNhMTZAZ21h aWwuY29tPiB3cm90ZToKPiBBdm9pZCAzIFZMQXNbMV0gYnkgdXNpbmcgcmVhbCBjb25zdGFudCBl eHByZXNzaW9ucyBpbnN0ZWFkIG9mIHZhcmlhYmxlcy4KPiBUaGUgY29tcGlsZXIgc2hvdWxkIGJl IGFibGUgdG8gb3B0aW1pemUgdGhlIG9yaWdpbmFsIGNvZGUgYW5kIGF2b2lkIHVzaW5nCj4gYW55 IGFjdHVhbCBWTEFzLiBBbnl3YXkgdGhpcyBjaGFuZ2UgaXMgdXNlZnVsIGJlY2F1c2UgaXQgd2ls bCBhdm9pZCBhIGZhbHNlCj4gcG9zaXRpdmVzIHdpdGggLVd2bGEsIGl0IG1pZ2h0IGFsc28gaGVs cCB0aGUgY29tcGlsZXIgZ2VuZXJhdGluZyBiZXR0ZXIKPiBjb2RlLgoKVGhhbmtzIGZvciB5b3Vy IHBhdGNoLiBIb3dldmVyLCBDaHJpcyBiZWF0IHlvdSB0byBpdCB3aXRoOgoKN2FhMGIxNGVkZTY0 ICgiZHJtL2k5MTU6IFJlbW92ZSB2YXJpYWJsZSBsZW5ndGggYXJyYXlzIGZyb20gc3NldSBkZWJ1 Z2ZzCnByaW50ZXJzIikKCmFzIHdlbGwgYXMgYWRkaW5nIC1XdmxhIHRvIG91ciBzdWJkaXItY2Nm bGFncy15IHRvIHByZXZlbnQgbW9yZSBmcm9tCmNyb3BwaW5nIHVwOgoKYzVjMmIxMTg5NGY0ICgi ZHJtL2k5MTU6IFdhcm4gYWdhaW5zdCB2YXJpYWJsZSBsZW5ndGggYXJyYXlzIikKCgpCUiwKSmFu aS4KCgotLSAKSmFuaSBOaWt1bGEsIEludGVsIE9wZW4gU291cmNlIFRlY2hub2xvZ3kgQ2VudGVy Cl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCkludGVsLWdm eCBtYWlsaW5nIGxpc3QKSW50ZWwtZ2Z4QGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xp c3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2ludGVsLWdmeAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELtX3VLKE1onXxnPFP22RMfciBSX5zLhmKqzm5pRVI750mSdOt+/6O0MYznfz2XSpDyweFqg ARC-Seal: i=1; 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mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12595-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12595-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12595-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12595-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,470,1515484800"; d="scan'208";a="37985401" From: Jani Nikula To: Salvatore Mesoraca , linux-kernel@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kernel-hardening@lists.openwall.com, David Airlie , Joonas Lahtinen , Kees Cook , Rodrigo Vivi , Salvatore Mesoraca Subject: Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c In-Reply-To: <1520970688-19683-1-git-send-email-s.mesoraca16@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <1520970688-19683-1-git-send-email-s.mesoraca16@gmail.com> Date: Wed, 14 Mar 2018 14:17:07 +0200 Message-ID: <87fu52n96k.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594853392696206560?= X-GMAIL-MSGID: =?utf-8?q?1594920044472440297?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, 13 Mar 2018, Salvatore Mesoraca wrote: > Avoid 3 VLAs[1] by using real constant expressions instead of variables. > The compiler should be able to optimize the original code and avoid using > any actual VLAs. Anyway this change is useful because it will avoid a false > positives with -Wvla, it might also help the compiler generating better > code. Thanks for your patch. However, Chris beat you to it with: 7aa0b14ede64 ("drm/i915: Remove variable length arrays from sseu debugfs printers") as well as adding -Wvla to our subdir-ccflags-y to prevent more from cropping up: c5c2b11894f4 ("drm/i915: Warn against variable length arrays") BR, Jani. -- Jani Nikula, Intel Open Source Technology Center