| Message ID | AS1PR01MB95648094D8A35D5C772293AD8F109@AS1PR01MB9564.eurprd01.prod.exchangelabs.com |
|---|---|
| State | Accepted |
| Commit | dd8a55cb3e2014934a176a9962010a3c87d12704 |
| Headers | show |
| Series | [FFmpeg-devel,01/21] avcodec/pngenc: Avoid potentially truncating integers | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
> +int ff_inflate_init(FFZStream *z, void *logctx) > +{ > + z_stream *const zstream = &z->zstream; > + int zret; > + > + z->inited = 0; > + zstream->next_in = Z_NULL; > + zstream->avail_in = 0; > + zstream->zalloc = Z_NULL; > + zstream->zfree = Z_NULL; > + zstream->opaque = Z_NULL; why not bzero()? Rest of the patch looks fine /Tomas
Tomas Härdin: >> +int ff_inflate_init(FFZStream *z, void *logctx) >> +{ >> + z_stream *const zstream = &z->zstream; >> + int zret; >> + >> + z->inited = 0; >> + zstream->next_in = Z_NULL; >> + zstream->avail_in = 0; >> + zstream->zalloc = Z_NULL; >> + zstream->zfree = Z_NULL; >> + zstream->opaque = Z_NULL; > > why not bzero()? > > Rest of the patch looks fine > bzero()? You mean memset to zero? The reason that I initialize exactly these fields is because these are exactly the fields required to be initialized by zlib (for inflate; next_in and avail_in are not required to be initialized for deflate): "The fields next_in, avail_in, zalloc, zfree and opaque must be initialized before by the caller." zlib treats all the other fields as uninitialized, so why should we initialize them (Actually reinitialize them -- most FFZStreams are already zeroed initially as part of a codec's private context.)? The way it is done in this patch shows directly which elements zlib expects to be set; setting everything would not achieve the same. - Andreas
ons 2022-03-16 klockan 20:32 +0100 skrev Andreas Rheinhardt: > Tomas Härdin: > > > +int ff_inflate_init(FFZStream *z, void *logctx) > > > +{ > > > + z_stream *const zstream = &z->zstream; > > > + int zret; > > > + > > > + z->inited = 0; > > > + zstream->next_in = Z_NULL; > > > + zstream->avail_in = 0; > > > + zstream->zalloc = Z_NULL; > > > + zstream->zfree = Z_NULL; > > > + zstream->opaque = Z_NULL; > > > > why not bzero()? > > > > Rest of the patch looks fine > > > > bzero()? You mean memset to zero? The reason that I initialize > exactly > these fields is because these are exactly the fields required to be > initialized by zlib (for inflate; next_in and avail_in are not > required > to be initialized for deflate): "The fields next_in, avail_in, > zalloc, > zfree and opaque must be initialized before by the caller." zlib > treats > all the other fields as uninitialized, so why should we initialize > them > (Actually reinitialize them -- most FFZStreams are already zeroed > initially as part of a codec's private context.)? The way it is done > in > this patch shows directly which elements zlib expects to be set; > setting > everything would not achieve the same. Right. Looks OK then /Tomas
Tomas Härdin: > ons 2022-03-16 klockan 20:32 +0100 skrev Andreas Rheinhardt: >> Tomas Härdin: >>>> +int ff_inflate_init(FFZStream *z, void *logctx) >>>> +{ >>>> + z_stream *const zstream = &z->zstream; >>>> + int zret; >>>> + >>>> + z->inited = 0; >>>> + zstream->next_in = Z_NULL; >>>> + zstream->avail_in = 0; >>>> + zstream->zalloc = Z_NULL; >>>> + zstream->zfree = Z_NULL; >>>> + zstream->opaque = Z_NULL; >>> >>> why not bzero()? >>> >>> Rest of the patch looks fine >>> >> >> bzero()? You mean memset to zero? The reason that I initialize >> exactly >> these fields is because these are exactly the fields required to be >> initialized by zlib (for inflate; next_in and avail_in are not >> required >> to be initialized for deflate): "The fields next_in, avail_in, >> zalloc, >> zfree and opaque must be initialized before by the caller." zlib >> treats >> all the other fields as uninitialized, so why should we initialize >> them >> (Actually reinitialize them -- most FFZStreams are already zeroed >> initially as part of a codec's private context.)? The way it is done >> in >> this patch shows directly which elements zlib expects to be set; >> setting >> everything would not achieve the same. > > Right. Looks OK then > Thanks for the review. Will apply this patchset tonight unless there are objections. - Andreas
diff --git a/configure b/configure index 82642deabe..6254dc9dc1 100755 --- a/configure +++ b/configure @@ -2461,6 +2461,7 @@ CONFIG_EXTRA=" idctdsp iirfilter mdct15 + inflate_wrapper intrax8 iso_media ividsp @@ -2722,6 +2723,7 @@ faanidct_select="idctdsp" h264dsp_select="startcode" hevcparse_select="atsc_a53 golomb" frame_thread_encoder_deps="encoders threads" +inflate_wrapper_deps="zlib" intrax8_select="blockdsp idctdsp" iso_media_select="mpeg4audio" mdct_select="fft" diff --git a/libavcodec/Makefile b/libavcodec/Makefile index f36b2e992d..62c8e34963 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -104,6 +104,7 @@ OBJS-$(CONFIG_HUFFYUVENCDSP) += huffyuvencdsp.o OBJS-$(CONFIG_IDCTDSP) += idctdsp.o simple_idct.o jrevdct.o OBJS-$(CONFIG_IIRFILTER) += iirfilter.o OBJS-$(CONFIG_MDCT15) += mdct15.o +OBJS-$(CONFIG_INFLATE_WRAPPER) += zlib_wrapper.o OBJS-$(CONFIG_INTRAX8) += intrax8.o intrax8dsp.o msmpeg4data.o OBJS-$(CONFIG_IVIDSP) += ivi_dsp.o OBJS-$(CONFIG_JNI) += ffjni.o jni.o diff --git a/libavcodec/zlib_wrapper.c b/libavcodec/zlib_wrapper.c new file mode 100644 index 0000000000..b15d5be2b8 --- /dev/null +++ b/libavcodec/zlib_wrapper.c @@ -0,0 +1,57 @@ +/* + * Wrappers for zlib + * Copyright (C) 2022 Andreas Rheinhardt + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <zlib.h> + +#include "libavutil/error.h" +#include "libavutil/log.h" +#include "zlib_wrapper.h" + +int ff_inflate_init(FFZStream *z, void *logctx) +{ + z_stream *const zstream = &z->zstream; + int zret; + + z->inited = 0; + zstream->next_in = Z_NULL; + zstream->avail_in = 0; + zstream->zalloc = Z_NULL; + zstream->zfree = Z_NULL; + zstream->opaque = Z_NULL; + + zret = inflateInit(zstream); + if (zret == Z_OK) { + z->inited = 1; + } else { + av_log(logctx, AV_LOG_ERROR, "inflateInit error %d, message: %s\n", + zret, zstream->msg ? zstream->msg : ""); + return AVERROR_EXTERNAL; + } + return 0; +} + +void ff_inflate_end(FFZStream *z) +{ + if (z->inited) { + z->inited = 0; + inflateEnd(&z->zstream); + } +} diff --git a/libavcodec/zlib_wrapper.h b/libavcodec/zlib_wrapper.h new file mode 100644 index 0000000000..0e91713b25 --- /dev/null +++ b/libavcodec/zlib_wrapper.h @@ -0,0 +1,51 @@ +/* + * Wrappers for zlib + * Copyright (C) 2022 Andreas Rheinhardt + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_ZLIB_WRAPPER_H +#define AVCODEC_ZLIB_WRAPPER_H + +#include <zlib.h> + +typedef struct FFZStream { + z_stream zstream; + int inited; +} FFZStream; + +/** + * Wrapper around inflateInit(). It initializes the fields that zlib + * requires to be initialized before inflateInit(). + * In case of error it also returns an error message to the provided logctx; + * in any case, it sets zstream->inited to indicate whether inflateInit() + * succeeded. + * @return Returns 0 on success or a negative error code on failure + */ +int ff_inflate_init(FFZStream *zstream, void *logctx); + +/** + * Wrapper around inflateEnd(). It calls inflateEnd() iff + * zstream->inited is set and resets zstream->inited. + * It is therefore safe to be called even if + * ff_inflate_init() has never been called on it (or errored out) + * provided that the FFZStream (or just FFZStream.inited) has been zeroed. + */ +void ff_inflate_end(FFZStream *zstream); + +#endif /* AVCODEC_ZLIB_WRAPPER_H */
It is not documented to be safe to call inflateEnd() on a z_stream that has never been successfully been initialized by inflateInit(), but just zeroed. It just happens to work and several codecs rely on this (they have FF_CODEC_CAP_INIT_CLEANUP set and even call inflateEnd() when inflateInit() failed or has never been called). To avoid this, other codecs recorded whether their zstream has been initialized successfully or not. This commit adds wrappers for inflateInit() and inflateEnd() that do what these other codecs do; furthermore, they also take care of properly setting up the zstream before inflateInit() and emit an error message in case of error. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> --- configure | 2 ++ libavcodec/Makefile | 1 + libavcodec/zlib_wrapper.c | 57 +++++++++++++++++++++++++++++++++++++++ libavcodec/zlib_wrapper.h | 51 +++++++++++++++++++++++++++++++++++ 4 files changed, 111 insertions(+) create mode 100644 libavcodec/zlib_wrapper.c create mode 100644 libavcodec/zlib_wrapper.h