diff mbox series

module/decompress: Support zstd in-kernel decompression

Message ID 20221206215318.3955400-1-swboyd@chromium.org (mailing list archive)
State New, archived
Headers show
Series module/decompress: Support zstd in-kernel decompression | expand

Commit Message

Stephen Boyd Dec. 6, 2022, 9:53 p.m. UTC 
Add support for zstd compressed modules to the in-kernel decompression
code. This allows zstd compressed modules to be decompressed by the
kernel, similar to the existing support for gzip and xz compressed
modules.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 kernel/module/Kconfig      |  3 +-
 kernel/module/decompress.c | 92 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 92 insertions(+), 3 deletions(-)


base-commit: 76dcd734eca23168cb008912c0f69ff408905235

Comments

Luis Chamberlain Dec. 6, 2022, 10:07 p.m. UTC | #1 
On Tue, Dec 06, 2022 at 01:53:18PM -0800, Stephen Boyd wrote:
> Add support for zstd compressed modules to the in-kernel decompression
> code. This allows zstd compressed modules to be decompressed by the
> kernel, similar to the existing support for gzip and xz compressed
> modules.
> 
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
> Cc: Nick Terrell <terrelln@fb.com>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>

Thanks, might as well get the bots to start testing this, so queued up for
modules-next.

  Luis
Dmitry Torokhov Dec. 7, 2022, 1:17 a.m. UTC | #2 
On Tue, Dec 06, 2022 at 01:53:18PM -0800, Stephen Boyd wrote:
> Add support for zstd compressed modules to the in-kernel decompression
> code. This allows zstd compressed modules to be decompressed by the
> kernel, similar to the existing support for gzip and xz compressed
> modules.
> 
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
> Cc: Nick Terrell <terrelln@fb.com>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>

Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Thanks.
Piotr Gorski Dec. 7, 2022, 4:53 p.m. UTC | #3 
Reviewed-by: Piotr Gorski <lucjan.lucjanov@gmail.com>

> Add support for zstd compressed modules to the in-kernel decompression
> code. This allows zstd compressed modules to be decompressed by the
> kernel, similar to the existing support for gzip and xz compressed
> modules.
>
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
> Cc: Nick Terrell <terrelln@fb.com>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>   kernel/module/Kconfig      |  3 +-
>   kernel/module/decompress.c | 92 +++++++++++++++++++++++++++++++++++++-
>   2 files changed, 92 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
> index 26ea5d04f56c..424b3bc58f3f 100644
> --- a/kernel/module/Kconfig
> +++ b/kernel/module/Kconfig
> @@ -221,9 +221,10 @@ endchoice
>   
>   config MODULE_DECOMPRESS
>   	bool "Support in-kernel module decompression"
> -	depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ
> +	depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ || MODULE_COMPRESS_ZSTD
>   	select ZLIB_INFLATE if MODULE_COMPRESS_GZIP
>   	select XZ_DEC if MODULE_COMPRESS_XZ
> +	select ZSTD_DECOMPRESS if MODULE_COMPRESS_ZSTD
>   	help
>   
>   	  Support for decompressing kernel modules by the kernel itself
> diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
> index c033572d83f0..44f14643d014 100644
> --- a/kernel/module/decompress.c
> +++ b/kernel/module/decompress.c
> @@ -50,7 +50,7 @@ static struct page *module_get_next_page(struct load_info *info)
>   	return page;
>   }
>   
> -#ifdef CONFIG_MODULE_COMPRESS_GZIP
> +#if defined(CONFIG_MODULE_COMPRESS_GZIP)
>   #include <linux/zlib.h>
>   #define MODULE_COMPRESSION	gzip
>   #define MODULE_DECOMPRESS_FN	module_gzip_decompress
> @@ -141,7 +141,7 @@ static ssize_t module_gzip_decompress(struct load_info *info,
>   	kfree(s.workspace);
>   	return retval;
>   }
> -#elif CONFIG_MODULE_COMPRESS_XZ
> +#elif defined(CONFIG_MODULE_COMPRESS_XZ)
>   #include <linux/xz.h>
>   #define MODULE_COMPRESSION	xz
>   #define MODULE_DECOMPRESS_FN	module_xz_decompress
> @@ -199,6 +199,94 @@ static ssize_t module_xz_decompress(struct load_info *info,
>   	xz_dec_end(xz_dec);
>   	return retval;
>   }
> +#elif defined(CONFIG_MODULE_COMPRESS_ZSTD)
> +#include <linux/zstd.h>
> +#define MODULE_COMPRESSION	zstd
> +#define MODULE_DECOMPRESS_FN	module_zstd_decompress
> +
> +static ssize_t module_zstd_decompress(struct load_info *info,
> +				    const void *buf, size_t size)
> +{
> +	static const u8 signature[] = { 0x28, 0xb5, 0x2f, 0xfd };
> +	ZSTD_outBuffer zstd_dec;
> +	ZSTD_inBuffer zstd_buf;
> +	zstd_frame_header header;
> +	size_t wksp_size;
> +	void *wksp = NULL;
> +	ZSTD_DStream *dstream;
> +	size_t ret;
> +	size_t new_size = 0;
> +	int retval;
> +
> +	if (size < sizeof(signature) ||
> +	    memcmp(buf, signature, sizeof(signature))) {
> +		pr_err("not a zstd compressed module\n");
> +		return -EINVAL;
> +	}
> +
> +	zstd_buf.src = buf;
> +	zstd_buf.pos = 0;
> +	zstd_buf.size = size;
> +
> +	ret = zstd_get_frame_header(&header, zstd_buf.src, zstd_buf.size);
> +	if (ret != 0) {
> +		pr_err("ZSTD-compressed data has an incomplete frame header\n");
> +		retval = -EINVAL;
> +		goto out;
> +	}
> +	if (header.windowSize > (1 << ZSTD_WINDOWLOG_MAX)) {
> +		pr_err("ZSTD-compressed data has too large a window size\n");
> +		retval = -EINVAL;
> +		goto out;
> +	}
> +
> +	wksp_size = zstd_dstream_workspace_bound(header.windowSize);
> +	wksp = kmalloc(wksp_size, GFP_KERNEL);
> +	if (!wksp) {
> +		retval = -ENOMEM;
> +		goto out;
> +	}
> +
> +	dstream = zstd_init_dstream(header.windowSize, wksp, wksp_size);
> +	if (!dstream) {
> +		pr_err("Can't initialize ZSTD stream\n");
> +		retval = -ENOMEM;
> +		goto out;
> +	}
> +
> +	do {
> +		struct page *page = module_get_next_page(info);
> +
> +		if (!IS_ERR(page)) {
> +			retval = PTR_ERR(page);
> +			goto out;
> +		}
> +
> +		zstd_dec.dst = kmap_local_page(page);
> +		zstd_dec.pos = 0;
> +		zstd_dec.size = PAGE_SIZE;
> +
> +		ret = zstd_decompress_stream(dstream, &zstd_dec, &zstd_buf);
> +		kunmap(page);
> +		retval = zstd_get_error_code(ret);
> +		if (retval)
> +			break;
> +
> +		new_size += zstd_dec.pos;
> +	} while (zstd_dec.pos == PAGE_SIZE && ret != 0);
> +
> +	if (retval) {
> +		pr_err("ZSTD-decompression failed with status %d\n", retval);
> +		retval = -EINVAL;
> +		goto out;
> +	}
> +
> +	retval = new_size;
> +
> + out:
> +	kfree(wksp);
> +	return retval;
> +}
>   #else
>   #error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS"
>   #endif
>
> base-commit: 76dcd734eca23168cb008912c0f69ff408905235
diff mbox series

Patch

diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 26ea5d04f56c..424b3bc58f3f 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -221,9 +221,10 @@  endchoice
 
 config MODULE_DECOMPRESS
 	bool "Support in-kernel module decompression"
-	depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ
+	depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ || MODULE_COMPRESS_ZSTD
 	select ZLIB_INFLATE if MODULE_COMPRESS_GZIP
 	select XZ_DEC if MODULE_COMPRESS_XZ
+	select ZSTD_DECOMPRESS if MODULE_COMPRESS_ZSTD
 	help
 
 	  Support for decompressing kernel modules by the kernel itself
diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index c033572d83f0..44f14643d014 100644
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -50,7 +50,7 @@  static struct page *module_get_next_page(struct load_info *info)
 	return page;
 }
 
-#ifdef CONFIG_MODULE_COMPRESS_GZIP
+#if defined(CONFIG_MODULE_COMPRESS_GZIP)
 #include <linux/zlib.h>
 #define MODULE_COMPRESSION	gzip
 #define MODULE_DECOMPRESS_FN	module_gzip_decompress
@@ -141,7 +141,7 @@  static ssize_t module_gzip_decompress(struct load_info *info,
 	kfree(s.workspace);
 	return retval;
 }
-#elif CONFIG_MODULE_COMPRESS_XZ
+#elif defined(CONFIG_MODULE_COMPRESS_XZ)
 #include <linux/xz.h>
 #define MODULE_COMPRESSION	xz
 #define MODULE_DECOMPRESS_FN	module_xz_decompress
@@ -199,6 +199,94 @@  static ssize_t module_xz_decompress(struct load_info *info,
 	xz_dec_end(xz_dec);
 	return retval;
 }
+#elif defined(CONFIG_MODULE_COMPRESS_ZSTD)
+#include <linux/zstd.h>
+#define MODULE_COMPRESSION	zstd
+#define MODULE_DECOMPRESS_FN	module_zstd_decompress
+
+static ssize_t module_zstd_decompress(struct load_info *info,
+				    const void *buf, size_t size)
+{
+	static const u8 signature[] = { 0x28, 0xb5, 0x2f, 0xfd };
+	ZSTD_outBuffer zstd_dec;
+	ZSTD_inBuffer zstd_buf;
+	zstd_frame_header header;
+	size_t wksp_size;
+	void *wksp = NULL;
+	ZSTD_DStream *dstream;
+	size_t ret;
+	size_t new_size = 0;
+	int retval;
+
+	if (size < sizeof(signature) ||
+	    memcmp(buf, signature, sizeof(signature))) {
+		pr_err("not a zstd compressed module\n");
+		return -EINVAL;
+	}
+
+	zstd_buf.src = buf;
+	zstd_buf.pos = 0;
+	zstd_buf.size = size;
+
+	ret = zstd_get_frame_header(&header, zstd_buf.src, zstd_buf.size);
+	if (ret != 0) {
+		pr_err("ZSTD-compressed data has an incomplete frame header\n");
+		retval = -EINVAL;
+		goto out;
+	}
+	if (header.windowSize > (1 << ZSTD_WINDOWLOG_MAX)) {
+		pr_err("ZSTD-compressed data has too large a window size\n");
+		retval = -EINVAL;
+		goto out;
+	}
+
+	wksp_size = zstd_dstream_workspace_bound(header.windowSize);
+	wksp = kmalloc(wksp_size, GFP_KERNEL);
+	if (!wksp) {
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	dstream = zstd_init_dstream(header.windowSize, wksp, wksp_size);
+	if (!dstream) {
+		pr_err("Can't initialize ZSTD stream\n");
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	do {
+		struct page *page = module_get_next_page(info);
+
+		if (!IS_ERR(page)) {
+			retval = PTR_ERR(page);
+			goto out;
+		}
+
+		zstd_dec.dst = kmap_local_page(page);
+		zstd_dec.pos = 0;
+		zstd_dec.size = PAGE_SIZE;
+
+		ret = zstd_decompress_stream(dstream, &zstd_dec, &zstd_buf);
+		kunmap(page);
+		retval = zstd_get_error_code(ret);
+		if (retval)
+			break;
+
+		new_size += zstd_dec.pos;
+	} while (zstd_dec.pos == PAGE_SIZE && ret != 0);
+
+	if (retval) {
+		pr_err("ZSTD-decompression failed with status %d\n", retval);
+		retval = -EINVAL;
+		goto out;
+	}
+
+	retval = new_size;
+
+ out:
+	kfree(wksp);
+	return retval;
+}
 #else
 #error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS"
 #endif