I was not able to find any existing zstd patch for kmod, so I wrote my own.
I was struggling to get the C code below the 80 character line length limit,
that's why I used gotos. I used descriptive label names, and it still looks
clean enough in my opinion.
I changed the style of the hackargs variable in autogen.sh to multiline
because said line was becoming a bit long with the new --with-zstd arg
added.
This patch has been running on my two Arch Linux installations (with an
accompanying mkinitcpio patch) for several months over many kernel updates
without any issues.
Any additional testing and/or patch review would of course be appreciated.
Signed-off-by: Torge Matthies <openglfreak@xxxxxxxxxxxxxx>
---
.semaphore/semaphore.yml | 4 +-
.travis.yml | 1 +
Makefile.am | 4 +-
autogen.sh | 9 ++-
configure.ac | 13 +++-
libkmod/libkmod-file.c | 119 +++++++++++++++++++++++++++++++++++
libkmod/libkmod.pc.in | 2 +-
shared/util.c | 3 +
testsuite/mkosi/mkosi.fedora | 1 +
testsuite/test-util.c | 3 +
10 files changed, 153 insertions(+), 6 deletions(-)
diff --git a/.semaphore/semaphore.yml b/.semaphore/semaphore.yml
index db47ca1..fe1d78a 100644
--- a/.semaphore/semaphore.yml
+++ b/.semaphore/semaphore.yml
@@ -22,7 +22,7 @@ blocks:
prologue:
commands:
- sudo apt update
- - sudo apt --yes install docbook-xsl liblzma-dev zlib1g-dev cython linux-headers-generic libssl-dev
+ - sudo apt --yes install docbook-xsl libzstd-dev liblzma-dev zlib1g-dev cython linux-headers-generic libssl-dev
- checkout
epilogue:
@@ -42,5 +42,5 @@ blocks:
prologue:
commands:
- sudo apt update
- - sudo apt --yes install docbook-xsl liblzma-dev zlib1g-dev cython linux-headers-generic libssl-dev
+ - sudo apt --yes install docbook-xsl libzstd-dev liblzma-dev zlib1g-dev cython linux-headers-generic libssl-dev
- checkout
diff --git a/.travis.yml b/.travis.yml
index 02c753e..0fcce14 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ matrix:
before_install:
- sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
- sudo apt-get update -qq
+ - sudo apt-get install -qq libzstd-dev
- sudo apt-get install -qq liblzma-dev
- sudo apt-get install -qq zlib1g-dev
- sudo apt-get install -qq xsltproc docbook-xsl
diff --git a/Makefile.am b/Makefile.am
index 8eadb99..37d840b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -31,6 +31,8 @@ SED_PROCESS = \
-e 's,@exec_prefix\@,$(exec_prefix),g' \
-e 's,@libdir\@,$(libdir),g' \
-e 's,@includedir\@,$(includedir),g' \
+ -e 's,@libzstd_CFLAGS\@,${libzstd_CFLAGS},g' \
+ -e 's,@libzstd_LIBS\@,${libzstd_LIBS},g' \
-e 's,@liblzma_CFLAGS\@,${liblzma_CFLAGS},g' \
-e 's,@liblzma_LIBS\@,${liblzma_LIBS},g' \
-e 's,@zlib_CFLAGS\@,${zlib_CFLAGS},g' \
@@ -90,7 +92,7 @@ libkmod_libkmod_la_DEPENDENCIES = \
${top_srcdir}/libkmod/libkmod.sym
libkmod_libkmod_la_LIBADD = \
shared/libshared.la \
- ${liblzma_LIBS} ${zlib_LIBS} ${libcrypto_LIBS}
+ ${libzstd_LIBS} ${liblzma_LIBS} ${zlib_LIBS} ${libcrypto_LIBS}
noinst_LTLIBRARIES += libkmod/libkmod-internal.la
libkmod_libkmod_internal_la_SOURCES = $(libkmod_libkmod_la_SOURCES)
diff --git a/autogen.sh b/autogen.sh
index 67b119f..e4997c4 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -32,7 +32,14 @@ fi
cd $oldpwd
-hackargs="--enable-debug --enable-python --with-xz --with-zlib --with-openssl"
+hackargs="\
+--enable-debug \
+--enable-python \
+--with-zstd \
+--with-xz \
+--with-zlib \
+--with-openssl \
+"
if [ "x$1" = "xc" ]; then
shift
diff --git a/configure.ac b/configure.ac
index 4a65d6b..a49f6b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -83,6 +83,17 @@ AC_ARG_WITH([rootlibdir],
[], [with_rootlibdir=$libdir])
AC_SUBST([rootlibdir], [$with_rootlibdir])
+AC_ARG_WITH([zstd],
+ AS_HELP_STRING([--with-zstd], [handle Zstandard-compressed modules @<:@default=disabled@:>@]),
+ [], [with_zstd=no])
+AS_IF([test "x$with_zstd" != "xno"], [
+ PKG_CHECK_MODULES([libzstd], [libzstd >= 1.4.4])
+ AC_DEFINE([ENABLE_ZSTD], [1], [Enable Zstandard for modules.])
+], [
+ AC_MSG_NOTICE([Zstandard support not requested])
+])
+CC_FEATURE_APPEND([with_features], [with_zstd], [ZSTD])
+
AC_ARG_WITH([xz],
AS_HELP_STRING([--with-xz], [handle Xz-compressed modules @<:@default=disabled@:>@]),
[], [with_xz=no])
@@ -307,7 +318,7 @@ AC_MSG_RESULT([
tools: ${enable_tools}
python bindings: ${enable_python}
logging: ${enable_logging}
- compression: xz=${with_xz} zlib=${with_zlib}
+ compression: zstd=${with_zstd} xz=${with_xz} zlib=${with_zlib}
debug: ${enable_debug}
coverage: ${enable_coverage}
doc: ${enable_gtk_doc}
diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index 5eeba6a..1a2e753 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -26,6 +26,9 @@
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
+#ifdef ENABLE_ZSTD
+#include <zstd.h>
+#endif
#ifdef ENABLE_XZ
#include <lzma.h>
#endif
@@ -45,6 +48,9 @@ struct file_ops {
};
struct kmod_file {
+#ifdef ENABLE_ZSTD
+ bool zstd_used;
+#endif
#ifdef ENABLE_XZ
bool xz_used;
#endif
@@ -60,6 +66,116 @@ struct kmod_file {
struct kmod_elf *elf;
};
+#ifdef ENABLE_ZSTD
+static int load_zstd(struct kmod_file *file)
+{
+ ZSTD_DStream *dstr = NULL;
+ size_t in_buf_size, out_buf_min_size, out_buf_size;
+ uint8_t *in_buf = NULL, *out_buf = NULL;
+ ZSTD_inBuffer zst_input;
+ ZSTD_outBuffer zst_output;
+ int ret = -EINVAL;
+
+ dstr = ZSTD_createDStream();
+ if (dstr == NULL) {
+ ERR(file->ctx, "zstd: Failed to create decompression stream\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ in_buf_size = ZSTD_initDStream(dstr);
+ in_buf = malloc(in_buf_size);
+ if (in_buf == NULL) {
+ ERR(file->ctx, "zstd: %s\n", strerror(ENOMEM));
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ out_buf_size = out_buf_min_size = ZSTD_DStreamOutSize();
+ out_buf = malloc(out_buf_size);
+ if (out_buf == NULL) {
+ ERR(file->ctx, "zstd: %s\n", strerror(ENOMEM));
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ zst_input.src = in_buf;
+ zst_output.dst = out_buf;
+ zst_output.size = out_buf_size;
+ zst_output.pos = 0;
+ while (true) {
+ ssize_t rdret;
+ size_t dsret;
+ uint8_t *tmp;
+
+ rdret = read(file->fd, in_buf, in_buf_size);
+ if (rdret < 0) {
+ ret = -errno;
+ goto out;
+ }
+ if (rdret == 0)
+ break;
+
+ zst_input.size = rdret;
+ zst_input.pos = 0;
+
+ if (zst_output.size - zst_output.pos < out_buf_min_size)
+ goto realloc_buffer;
+
+try_decompress:
+ dsret = ZSTD_decompressStream(dstr, &zst_output, &zst_input);
+ if (ZSTD_isError(dsret)) {
+ ERR(file->ctx, "zstd: %s\n", ZSTD_getErrorName(dsret));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (zst_output.pos < zst_output.size
+ && zst_output.size - zst_output.pos
+ >= out_buf_min_size) {
+ if (zst_input.pos < zst_input.size)
+ goto try_decompress;
+ else
+ continue;
+ }
+
+realloc_buffer:
+ tmp = realloc(out_buf, out_buf_size + out_buf_min_size);
+ if (tmp == NULL) {
+ ret = -errno;
+ goto out;
+ }
+ out_buf_size += out_buf_min_size;
+ out_buf = tmp;
+ zst_output.dst = out_buf;
+ zst_output.size = out_buf_size;
+ goto try_decompress;
+ }
+
+ ZSTD_freeDStream(dstr);
+ free(in_buf);
+ file->zstd_used = true;
+ file->memory = out_buf;
+ file->size = zst_output.pos;
+ return 0;
+out:
+ if (dstr != NULL)
+ ZSTD_freeDStream(dstr);
+ free(out_buf);
+ free(in_buf);
+ return ret;
+}
+
+static void unload_zstd(struct kmod_file *file)
+{
+ if (!file->zstd_used)
+ return;
+ free(file->memory);
+}
+
+static const char magic_zstd[] = {0x28, 0xB5, 0x2F, 0xFD};
+#endif
+
#ifdef ENABLE_XZ
static void xz_uncompress_belch(struct kmod_file *file, lzma_ret ret)
{
@@ -238,6 +354,9 @@ static const struct comp_type {
const char *magic_bytes;
const struct file_ops ops;
} comp_types[] = {
+#ifdef ENABLE_ZSTD
+ {sizeof(magic_zstd), magic_zstd, {load_zstd, unload_zstd}},
+#endif
#ifdef ENABLE_XZ
{sizeof(magic_xz), magic_xz, {load_xz, unload_xz}},
#endif
diff --git a/libkmod/libkmod.pc.in b/libkmod/libkmod.pc.in
index e4fdf21..3acca6a 100644
--- a/libkmod/libkmod.pc.in
+++ b/libkmod/libkmod.pc.in
@@ -7,5 +7,5 @@ Name: libkmod
Description: Library to deal with kernel modules
Version: @VERSION@
Libs: -L${libdir} -lkmod
-Libs.private: @liblzma_LIBS@ @zlib_LIBS@
+Libs.private: @libzstd_LIBS@ @liblzma_LIBS@ @zlib_LIBS@
Cflags: -I${includedir}
diff --git a/shared/util.c b/shared/util.c
index fd2028d..b487b5f 100644
--- a/shared/util.c
+++ b/shared/util.c
@@ -45,6 +45,9 @@ static const struct kmod_ext {
#endif
#ifdef ENABLE_XZ
{".ko.xz", sizeof(".ko.xz") - 1},
+#endif
+#ifdef ENABLE_ZSTD
+ {".ko.zst", sizeof(".ko.zst") - 1},
#endif
{ }
};
diff --git a/testsuite/mkosi/mkosi.fedora b/testsuite/mkosi/mkosi.fedora
index 5252f87..7a2ee5e 100644
--- a/testsuite/mkosi/mkosi.fedora
+++ b/testsuite/mkosi/mkosi.fedora
@@ -19,6 +19,7 @@ BuildPackages =
make
pkgconf-pkg-config
xml-common
+ libzstd-devel
xz-devel
zlib-devel
openssl-devel
diff --git a/testsuite/test-util.c b/testsuite/test-util.c
index 5e25e58..621446b 100644
--- a/testsuite/test-util.c
+++ b/testsuite/test-util.c
@@ -156,6 +156,9 @@ static int test_path_ends_with_kmod_ext(const struct test *t)
#endif
#ifdef ENABLE_XZ
{ "/bla.ko.xz", true },
+#endif
+#ifdef ENABLE_ZSTD
+ { "/bla.ko.zst", true },
#endif
{ "/bla.ko.x", false },
{ "/bla.ko.", false },
--
2.28.0
