From patchwork Wed Jan 8 18:12:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 11324255 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 25938138C for ; Wed, 8 Jan 2020 18:12:49 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 09C0620656 for ; Wed, 8 Jan 2020 18:12:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09C0620656 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CF4B689C60; Wed, 8 Jan 2020 18:12:46 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6DEC989C60 for ; Wed, 8 Jan 2020 18:12:46 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2020 10:12:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,410,1571727600"; d="scan'208";a="218135017" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by fmsmga008.fm.intel.com with SMTP; 08 Jan 2020 10:12:43 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 08 Jan 2020 20:12:42 +0200 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Date: Wed, 8 Jan 2020 20:12:34 +0200 Message-Id: <20200108181242.13650-1-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 1/9] drm/i915/sdvo: Reduce the size of the on stack buffers X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" From: Ville Syrjälä The strings we want to print to the on stack buffers should be no more than 8 * 3 + strlen("(GET_SCALED_HDTV_RESOLUTION_SUPPORT)") + 1 = 61 bytes. So let's shrink the buffers down to 64 bytes. Also switch the BUG_ON()s to WARN_ON()s if I made a mistake in my arithmentic. Signed-off-by: Ville Syrjälä Reviewed-by: Jani Nikula --- drivers/gpu/drm/i915/display/intel_sdvo.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c index 8758ee2a4442..02119c827c80 100644 --- a/drivers/gpu/drm/i915/display/intel_sdvo.c +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c @@ -414,12 +414,10 @@ static void intel_sdvo_debug_write(struct intel_sdvo *intel_sdvo, u8 cmd, { const char *cmd_name; int i, pos = 0; -#define BUF_LEN 256 - char buffer[BUF_LEN]; + char buffer[64]; #define BUF_PRINT(args...) \ - pos += snprintf(buffer + pos, max_t(int, BUF_LEN - pos, 0), args) - + pos += snprintf(buffer + pos, max_t(int, sizeof(buffer) - pos, 0), args) for (i = 0; i < args_len; i++) { BUF_PRINT("%02X ", ((u8 *)args)[i]); @@ -433,9 +431,9 @@ static void intel_sdvo_debug_write(struct intel_sdvo *intel_sdvo, u8 cmd, BUF_PRINT("(%s)", cmd_name); else BUF_PRINT("(%02X)", cmd); - BUG_ON(pos >= BUF_LEN - 1); + + WARN_ON(pos >= sizeof(buffer) - 1); #undef BUF_PRINT -#undef BUF_LEN DRM_DEBUG_KMS("%s: W: %02X %s\n", SDVO_NAME(intel_sdvo), cmd, buffer); } @@ -540,8 +538,7 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, u8 retry = 15; /* 5 quick checks, followed by 10 long checks */ u8 status; int i, pos = 0; -#define BUF_LEN 256 - char buffer[BUF_LEN]; + char buffer[64]; buffer[0] = '\0'; @@ -581,7 +578,7 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, } #define BUF_PRINT(args...) \ - pos += snprintf(buffer + pos, max_t(int, BUF_LEN - pos, 0), args) + pos += snprintf(buffer + pos, max_t(int, sizeof(buffer) - pos, 0), args) cmd_status = sdvo_cmd_status(status); if (cmd_status) @@ -600,9 +597,9 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, goto log_fail; BUF_PRINT(" %02X", ((u8 *)response)[i]); } - BUG_ON(pos >= BUF_LEN - 1); + + WARN_ON(pos >= sizeof(buffer) - 1); #undef BUF_PRINT -#undef BUF_LEN DRM_DEBUG_KMS("%s: R: %s\n", SDVO_NAME(intel_sdvo), buffer); return true;