From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id AAD2F46E2D for ; Fri, 14 Jul 2023 16:10:58 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 0764A68C621; Fri, 14 Jul 2023 19:10:54 +0300 (EEST) Received: from ursule.remlab.net (vps-a2bccee9.vps.ovh.net [51.75.19.47]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id BD3A268C4C5 for ; Fri, 14 Jul 2023 19:10:47 +0300 (EEST) Received: from basile.remlab.net (localhost [IPv6:::1]) by ursule.remlab.net (Postfix) with ESMTP id 602C3C000E for ; Fri, 14 Jul 2023 19:10:47 +0300 (EEST) From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= To: ffmpeg-devel@ffmpeg.org Date: Fri, 14 Jul 2023 19:10:47 +0300 Message-Id: <20230714161047.3196-1-remi@remlab.net> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH] lavc/audiodsp: fix aliasing violation X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Even though they have the same size, and typically the same alignment, uint32_t and float are under no circumstances compatible types in C. The casts from float * to uint32_t * are invalid here. Insofar as the resulting pointers are dereferenced, this is undefined behaviour. This patch uses av_float2int() / av_int2float() instead. --- libavcodec/audiodsp.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/libavcodec/audiodsp.c b/libavcodec/audiodsp.c index eba6e809fd..c5427d3535 100644 --- a/libavcodec/audiodsp.c +++ b/libavcodec/audiodsp.c @@ -22,36 +22,36 @@ #include "libavutil/common.h" #include "audiodsp.h" -static inline uint32_t clipf_c_one(uint32_t a, uint32_t mini, - uint32_t maxi, uint32_t maxisign) +static inline float clipf_c_one(float a, uint32_t mini, + uint32_t maxi, uint32_t maxisign) { - if (a > mini) - return mini; - else if ((a ^ (1U << 31)) > maxisign) - return maxi; + uint32_t ai = av_float2int(a); + + if (ai > mini) + return av_int2float(mini); + else if ((ai ^ (1U << 31)) > maxisign) + return av_int2float(maxi); else return a; } static void vector_clipf_c_opposite_sign(float *dst, const float *src, - float *min, float *max, int len) + float min, float max, int len) { int i; - uint32_t mini = *(uint32_t *) min; - uint32_t maxi = *(uint32_t *) max; + uint32_t mini = av_float2int(min); + uint32_t maxi = av_float2int(max); uint32_t maxisign = maxi ^ (1U << 31); - uint32_t *dsti = (uint32_t *) dst; - const uint32_t *srci = (const uint32_t *) src; for (i = 0; i < len; i += 8) { - dsti[i + 0] = clipf_c_one(srci[i + 0], mini, maxi, maxisign); - dsti[i + 1] = clipf_c_one(srci[i + 1], mini, maxi, maxisign); - dsti[i + 2] = clipf_c_one(srci[i + 2], mini, maxi, maxisign); - dsti[i + 3] = clipf_c_one(srci[i + 3], mini, maxi, maxisign); - dsti[i + 4] = clipf_c_one(srci[i + 4], mini, maxi, maxisign); - dsti[i + 5] = clipf_c_one(srci[i + 5], mini, maxi, maxisign); - dsti[i + 6] = clipf_c_one(srci[i + 6], mini, maxi, maxisign); - dsti[i + 7] = clipf_c_one(srci[i + 7], mini, maxi, maxisign); + dst[i + 0] = clipf_c_one(src[i + 0], mini, maxi, maxisign); + dst[i + 1] = clipf_c_one(src[i + 1], mini, maxi, maxisign); + dst[i + 2] = clipf_c_one(src[i + 2], mini, maxi, maxisign); + dst[i + 3] = clipf_c_one(src[i + 3], mini, maxi, maxisign); + dst[i + 4] = clipf_c_one(src[i + 4], mini, maxi, maxisign); + dst[i + 5] = clipf_c_one(src[i + 5], mini, maxi, maxisign); + dst[i + 6] = clipf_c_one(src[i + 6], mini, maxi, maxisign); + dst[i + 7] = clipf_c_one(src[i + 7], mini, maxi, maxisign); } } @@ -61,7 +61,7 @@ static void vector_clipf_c(float *dst, const float *src, int len, int i; if (min < 0 && max > 0) { - vector_clipf_c_opposite_sign(dst, src, &min, &max, len); + vector_clipf_c_opposite_sign(dst, src, min, max, len); } else { for (i = 0; i < len; i += 8) { dst[i] = av_clipf(src[i], min, max); -- 2.40.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".