From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 012A3C282D8 for ; Wed, 30 Jan 2019 23:30:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7716218D2 for ; Wed, 30 Jan 2019 23:30:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730826AbfA3Xai (ORCPT ); Wed, 30 Jan 2019 18:30:38 -0500 Received: from gateway34.websitewelcome.com ([192.185.149.62]:35986 "EHLO gateway34.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725768AbfA3Xah (ORCPT ); Wed, 30 Jan 2019 18:30:37 -0500 Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway34.websitewelcome.com (Postfix) with ESMTP id EAA5EEA9D for ; Wed, 30 Jan 2019 17:30:35 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id ozJTgaxDR90onozJTg0q7z; Wed, 30 Jan 2019 17:30:35 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=57884 helo=[192.168.1.76]) by gator4166.hostgator.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.91) (envelope-from ) id 1gozJT-0017Wf-KM; Wed, 30 Jan 2019 17:30:35 -0600 To: Kees Cook Cc: LKML References: <20190129233426.GA7999@embeddedor> From: "Gustavo A. R. Silva" Openpgp: preference=signencrypt Autocrypt: addr=gustavo@embeddedor.com; keydata= mQINBFssHAwBEADIy3ZoPq3z5UpsUknd2v+IQud4TMJnJLTeXgTf4biSDSrXn73JQgsISBwG 2Pm4wnOyEgYUyJd5tRWcIbsURAgei918mck3tugT7AQiTUN3/5aAzqe/4ApDUC+uWNkpNnSV tjOx1hBpla0ifywy4bvFobwSh5/I3qohxDx+c1obd8Bp/B/iaOtnq0inli/8rlvKO9hp6Z4e DXL3PlD0QsLSc27AkwzLEc/D3ZaqBq7ItvT9Pyg0z3Q+2dtLF00f9+663HVC2EUgP25J3xDd 496SIeYDTkEgbJ7WYR0HYm9uirSET3lDqOVh1xPqoy+U9zTtuA9NQHVGk+hPcoazSqEtLGBk YE2mm2wzX5q2uoyptseSNceJ+HE9L+z1KlWW63HhddgtRGhbP8pj42bKaUSrrfDUsicfeJf6 m1iJRu0SXYVlMruGUB1PvZQ3O7TsVfAGCv85pFipdgk8KQnlRFkYhUjLft0u7CL1rDGZWDDr NaNj54q2CX9zuSxBn9XDXvGKyzKEZ4NY1Jfw+TAMPCp4buawuOsjONi2X0DfivFY+ZsjAIcx qQMglPtKk/wBs7q2lvJ+pHpgvLhLZyGqzAvKM1sVtRJ5j+ARKA0w4pYs5a5ufqcfT7dN6TBk LXZeD9xlVic93Ju08JSUx2ozlcfxq+BVNyA+dtv7elXUZ2DrYwARAQABtCxHdXN0YXZvIEEu IFIuIFNpbHZhIDxndXN0YXZvQGVtYmVkZGVkb3IuY29tPokCPQQTAQgAJwUCWywcDAIbIwUJ CWYBgAULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRBHBbTLRwbbMZ6tEACk0hmmZ2FWL1Xi l/bPqDGFhzzexrdkXSfTTZjBV3a+4hIOe+jl6Rci/CvRicNW4H9yJHKBrqwwWm9fvKqOBAg9 obq753jydVmLwlXO7xjcfyfcMWyx9QdYLERTeQfDAfRqxir3xMeOiZwgQ6dzX3JjOXs6jHBP cgry90aWbaMpQRRhaAKeAS14EEe9TSIly5JepaHoVdASuxklvOC0VB0OwNblVSR2S5i5hSsh ewbOJtwSlonsYEj4EW1noQNSxnN/vKuvUNegMe+LTtnbbocFQ7dGMsT3kbYNIyIsp42B5eCu JXnyKLih7rSGBtPgJ540CjoPBkw2mCfhj2p5fElRJn1tcX2McsjzLFY5jK9RYFDavez5w3lx JFgFkla6sQHcrxH62gTkb9sUtNfXKucAfjjCMJ0iuQIHRbMYCa9v2YEymc0k0RvYr43GkA3N PJYd/vf9vU7VtZXaY4a/dz1d9dwIpyQARFQpSyvt++R74S78eY/+lX8wEznQdmRQ27kq7BJS R20KI/8knhUNUJR3epJu2YFT/JwHbRYC4BoIqWl+uNvDf+lUlI/D1wP+lCBSGr2LTkQRoU8U 64iK28BmjJh2K3WHmInC1hbUucWT7Swz/+6+FCuHzap/cjuzRN04Z3Fdj084oeUNpP6+b9yW e5YnLxF8ctRAp7K4yVlvA7kCDQRbLBwMARAAsHCE31Ffrm6uig1BQplxMV8WnRBiZqbbsVJB H1AAh8tq2ULl7udfQo1bsPLGGQboJSVN9rckQQNahvHAIK8ZGfU4Qj8+CER+fYPp/MDZj+t0 DbnWSOrG7z9HIZo6PR9z4JZza3Hn/35jFggaqBtuydHwwBANZ7A6DVY+W0COEU4of7CAahQo 5NwYiwS0lGisLTqks5R0Vh+QpvDVfuaF6I8LUgQR/cSgLkR//V1uCEQYzhsoiJ3zc1HSRyOP otJTApqGBq80X0aCVj1LOiOF4rrdvQnj6iIlXQssdb+WhSYHeuJj1wD0ZlC7ds5zovXh+FfF l5qH5RFY/qVn3mNIVxeO987WSF0jh+T5ZlvUNdhedGndRmwFTxq2Li6GNMaolgnpO/CPcFpD jKxY/HBUSmaE9rNdAa1fCd4RsKLlhXda+IWpJZMHlmIKY8dlUybP+2qDzP2lY7kdFgPZRU+e zS/pzC/YTzAvCWM3tDgwoSl17vnZCr8wn2/1rKkcLvTDgiJLPCevqpTb6KFtZosQ02EGMuHQ I6Zk91jbx96nrdsSdBLGH3hbvLvjZm3C+fNlVb9uvWbdznObqcJxSH3SGOZ7kCHuVmXUcqoz ol6ioMHMb+InrHPP16aVDTBTPEGwgxXI38f7SUEn+NpbizWdLNz2hc907DvoPm6HEGCanpcA EQEAAYkCJQQYAQgADwUCWywcDAIbDAUJCWYBgAAKCRBHBbTLRwbbMdsZEACUjmsJx2CAY+QS UMebQRFjKavwXB/xE7fTt2ahuhHT8qQ/lWuRQedg4baInw9nhoPE+VenOzhGeGlsJ0Ys52sd XvUjUocKgUQq6ekOHbcw919nO5L9J2ejMf/VC/quN3r3xijgRtmuuwZjmmi8ct24TpGeoBK4 WrZGh/1hAYw4ieARvKvgjXRstcEqM5thUNkOOIheud/VpY+48QcccPKbngy//zNJWKbRbeVn imua0OpqRXhCrEVm/xomeOvl1WK1BVO7z8DjSdEBGzbV76sPDJb/fw+y+VWrkEiddD/9CSfg fBNOb1p1jVnT2mFgGneIWbU0zdDGhleI9UoQTr0e0b/7TU+Jo6TqwosP9nbk5hXw6uR5k5PF 8ieyHVq3qatJ9K1jPkBr8YWtI5uNwJJjTKIA1jHlj8McROroxMdI6qZ/wZ1ImuylpJuJwCDC ORYf5kW61fcrHEDlIvGc371OOvw6ejF8ksX5+L2zwh43l/pKkSVGFpxtMV6d6J3eqwTafL86 YJWH93PN+ZUh6i6Rd2U/i8jH5WvzR57UeWxE4P8bQc0hNGrUsHQH6bpHV2lbuhDdqo+cM9eh GZEO3+gCDFmKrjspZjkJbB5Gadzvts5fcWGOXEvuT8uQSvl+vEL0g6vczsyPBtqoBLa9SNrS VtSixD1uOgytAP7RWS474w== Subject: Re: [PATCH] lib: zstd: Mark expected switch fall-throughs Message-ID: Date: Wed, 30 Jan 2019 17:30:34 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.130.205 X-Source-L: No X-Exim-ID: 1gozJT-0017Wf-KM X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: ([192.168.1.76]) [189.250.130.205]:57884 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 2 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/30/19 1:58 AM, Kees Cook wrote: > On Wed, Jan 30, 2019 at 12:34 PM Gustavo A. R. Silva > wrote: >> >> In preparation to enabling -Wimplicit-fallthrough, mark switch >> cases where we are expecting to fall through. >> >> This patch fixes the following warnings: >> >> lib/zstd/bitstream.h:261:30: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/bitstream.h:262:30: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/bitstream.h:263:30: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/bitstream.h:264:30: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/bitstream.h:265:30: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/compress.c:3183:16: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/decompress.c:1770:18: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/decompress.c:2376:15: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/decompress.c:2404:15: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/decompress.c:2435:16: warning: this statement may fall through [-Wimplicit-fallthrough=] >> lib/zstd/huf_compress.c: In function ‘HUF_compress1X_usingCTable’: >> lib/zstd/huf_compress.c:535:5: warning: this statement may fall through [-Wimplicit-fallthrough=] >> if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 4 + 7) \ >> ^ >> lib/zstd/huf_compress.c:558:54: note: in expansion of macro ‘HUF_FLUSHBITS_2’ >> case 3: HUF_encodeSymbol(&bitC, ip[n + 2], CTable); HUF_FLUSHBITS_2(&bitC); >> ^~~~~~~~~~~~~~~ >> lib/zstd/huf_compress.c:559:2: note: here >> case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC); >> ^~~~ >> lib/zstd/huf_compress.c:531:5: warning: this statement may fall through [-Wimplicit-fallthrough=] >> if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 2 + 7) \ >> ^ >> lib/zstd/huf_compress.c:559:54: note: in expansion of macro ‘HUF_FLUSHBITS_1’ >> case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC); >> ^~~~~~~~~~~~~~~ >> lib/zstd/huf_compress.c:560:2: note: here >> case 1: HUF_encodeSymbol(&bitC, ip[n + 0], CTable); HUF_FLUSHBITS(&bitC); >> ^~~~ >> AR lib/zstd//built-in.a >> >> Warning level 3 was used: -Wimplicit-fallthrough=3 >> >> This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough. >> >> Signed-off-by: Gustavo A. R. Silva >> --- >> lib/zstd/bitstream.h | 5 +++++ >> lib/zstd/compress.c | 1 + >> lib/zstd/decompress.c | 5 ++++- >> lib/zstd/huf_compress.c | 2 ++ >> 4 files changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/lib/zstd/bitstream.h b/lib/zstd/bitstream.h >> index a826b99e1d63..3a49784d5c61 100644 >> --- a/lib/zstd/bitstream.h >> +++ b/lib/zstd/bitstream.h >> @@ -259,10 +259,15 @@ ZSTD_STATIC size_t BIT_initDStream(BIT_DStream_t *bitD, const void *srcBuffer, s >> bitD->bitContainer = *(const BYTE *)(bitD->start); >> switch (srcSize) { >> case 7: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[6]) << (sizeof(bitD->bitContainer) * 8 - 16); >> + /* fall through */ >> case 6: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[5]) << (sizeof(bitD->bitContainer) * 8 - 24); >> + /* fall through */ >> case 5: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[4]) << (sizeof(bitD->bitContainer) * 8 - 32); >> + /* fall through */ >> case 4: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[3]) << 24; >> + /* fall through */ >> case 3: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[2]) << 16; >> + /* fall through */ >> case 2: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[1]) << 8; >> default:; >> } >> diff --git a/lib/zstd/compress.c b/lib/zstd/compress.c >> index f9166cf4f7a9..5e0b67003e55 100644 >> --- a/lib/zstd/compress.c >> +++ b/lib/zstd/compress.c >> @@ -3182,6 +3182,7 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream *zcs, void *dst, size_t * >> zcs->outBuffFlushedSize = 0; >> zcs->stage = zcss_flush; /* pass-through to flush stage */ >> } >> + /* fall through */ > > Perhaps reword the existing comment and move it down? > >> >> case zcss_flush: { >> size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize; >> diff --git a/lib/zstd/decompress.c b/lib/zstd/decompress.c >> index b17846725ca0..269ee9a796c1 100644 >> --- a/lib/zstd/decompress.c >> +++ b/lib/zstd/decompress.c >> @@ -1768,6 +1768,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, c >> return 0; >> } >> dctx->expected = 0; /* not necessary to copy more */ >> + /* fall through */ >> >> case ZSTDds_decodeFrameHeader: >> memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected); >> @@ -2375,7 +2376,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream *zds, ZSTD_outBuffer *output, ZSTD_inB >> } >> zds->stage = zdss_read; >> } >> - /* pass-through */ >> + /* fall through */ >> >> case zdss_read: { >> size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx); >> @@ -2404,6 +2405,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream *zds, ZSTD_outBuffer *output, ZSTD_inB >> zds->stage = zdss_load; >> /* pass-through */ >> } >> + /* fall through */ > > Same ("pass-through" exists a couple lines up) > >> >> case zdss_load: { >> size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx); >> @@ -2436,6 +2438,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream *zds, ZSTD_outBuffer *output, ZSTD_inB >> /* pass-through */ >> } >> } >> + /* fall through */ > > Same Yeah. The thing is that the pass-though comment is embedded in two nested blocks of code. And GCC triggers a warning if the fall-through comments are not placed at the very bottom of the case statement (some people dislike this 'feature'). That's the reason why I didn't want to change any of the pass-through comments, and instead added the fall-through comments at the bottom of every case. What do you think about this 'feature'? > >> >> case zdss_flush: { >> size_t const toFlushSize = zds->outEnd - zds->outStart; >> diff --git a/lib/zstd/huf_compress.c b/lib/zstd/huf_compress.c >> index 40055a7016e6..e727812d12aa 100644 >> --- a/lib/zstd/huf_compress.c >> +++ b/lib/zstd/huf_compress.c >> @@ -556,7 +556,9 @@ size_t HUF_compress1X_usingCTable(void *dst, size_t dstSize, const void *src, si >> n = srcSize & ~3; /* join to mod 4 */ >> switch (srcSize & 3) { >> case 3: HUF_encodeSymbol(&bitC, ip[n + 2], CTable); HUF_FLUSHBITS_2(&bitC); >> + /* fall through */ >> case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC); >> + /* fall through */ >> case 1: HUF_encodeSymbol(&bitC, ip[n + 0], CTable); HUF_FLUSHBITS(&bitC); >> case 0: >> default:; >> -- >> 2.20.1 >> > > Otherwise, yup, looks good. > > Reviewed-by: Kees Cook > Thanks -- Gustavo