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Commit fe1d4758 authored by Kees Cook's avatar Kees Cook
Browse files

pstore: Select compression at runtime 



To allow for easier build test coverage and run-time testing, this allows
multiple compression algorithms to be built into pstore. Still only one
is supported to operate at a time (which can be selected at build time
or at boot time, similar to how LSMs are selected).

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 55597406

fs/pstore/Kconfig

+67 −29
Original line number Diff line number Diff line
@@ -12,55 +12,93 @@ config PSTORE 
	   If you don't have a platform persistent store driver,

	   say N.



choice

        prompt "Choose compression algorithm"

        depends on PSTORE

        default PSTORE_ZLIB_COMPRESS

        help

          This option chooses compression algorithm.



	  Currently, pstore has support for 5 compression algorithms:

	  zlib, lzo, lz4, lz4hc and 842.



	  The default compression algorithm is zlib.



config PSTORE_ZLIB_COMPRESS

        bool "ZLIB"

	bool "ZLIB compression"

	default y

	depends on PSTORE

	select ZLIB_DEFLATE

	select ZLIB_INFLATE

	help

	  This option enables ZLIB compression algorithm support.



config PSTORE_LZO_COMPRESS

        bool "LZO"

	bool "LZO compression"

	depends on PSTORE

	select LZO_COMPRESS

	select LZO_DECOMPRESS

	help

	  This option enables LZO compression algorithm support.



config PSTORE_LZ4_COMPRESS

        bool "LZ4"

	bool "LZ4 compression"

	depends on PSTORE

	select LZ4_COMPRESS

	select LZ4_DECOMPRESS

	help

	  This option enables LZ4 compression algorithm support.



config PSTORE_LZ4HC_COMPRESS

	bool "LZ4HC"

	bool "LZ4HC compression"

	depends on PSTORE

	select LZ4HC_COMPRESS

	select LZ4_DECOMPRESS

	help

	  This option enables LZ4HC (high compression) mode algorithm.



config PSTORE_842_COMPRESS

	bool "842"

	bool "842 compression"

	depends on PSTORE

	select 842_COMPRESS

	select 842_DECOMPRESS

	help

	  This option enables 842 compression algorithm support.



config PSTORE_COMPRESS

	def_bool y

	depends on PSTORE

	depends on PSTORE_ZLIB_COMPRESS || PSTORE_LZO_COMPRESS ||	\

		   PSTORE_LZ4_COMPRESS || PSTORE_LZ4HC_COMPRESS ||	\

		   PSTORE_842_COMPRESS



choice

	prompt "Default pstore compression algorithm"

	depends on PSTORE_COMPRESS

	help

	  This option chooses the default active compression algorithm.

	  This change be changed at boot with "pstore.compress=..." on

	  the kernel command line.



	  Currently, pstore has support for 5 compression algorithms:

	  zlib, lzo, lz4, lz4hc and 842.



	  The default compression algorithm is zlib.



	config PSTORE_ZLIB_COMPRESS_DEFAULT

		bool "zlib" if PSTORE_ZLIB_COMPRESS=y



	config PSTORE_LZO_COMPRESS_DEFAULT

		bool "lzo" if PSTORE_LZO_COMPRESS=y



	config PSTORE_LZ4_COMPRESS_DEFAULT

		bool "lz4" if PSTORE_LZ4_COMPRESS=y



	config PSTORE_LZ4HC_COMPRESS_DEFAULT

		bool "lz4hc" if PSTORE_LZ4HC_COMPRESS=y



	config PSTORE_842_COMPRESS_DEFAULT

		bool "842" if PSTORE_842_COMPRESS=y



endchoice



config PSTORE_COMPRESS_DEFAULT

	string

	depends on PSTORE_COMPRESS

	default "zlib" if PSTORE_ZLIB_COMPRESS_DEFAULT

	default "lzo" if PSTORE_LZO_COMPRESS_DEFAULT

	default "lz4" if PSTORE_LZ4_COMPRESS_DEFAULT

	default "lz4hc" if PSTORE_LZ4HC_COMPRESS_DEFAULT

	default "842" if PSTORE_842_COMPRESS_DEFAULT



config PSTORE_CONSOLE

	bool "Log kernel console messages"

	depends on PSTORE

fs/pstore/inode.c

+2 −0
Original line number Diff line number Diff line
@@ -486,6 +486,8 @@ static int __init init_pstore_fs(void) 
{

	int err;



	pstore_choose_compression();



	/* Create a convenient mount point for people to access pstore */

	err = sysfs_create_mount_point(fs_kobj, "pstore");

	if (err)

fs/pstore/internal.h

+3 −0
Original line number Diff line number Diff line
@@ -37,4 +37,7 @@ extern bool pstore_is_mounted(void); 
extern void	pstore_record_init(struct pstore_record *record,

				   struct pstore_info *psi);



/* Called during module_init() */

extern void __init pstore_choose_compression(void);



#endif

fs/pstore/platform.c

+79 −55
Original line number Diff line number Diff line
@@ -77,6 +77,12 @@ static DEFINE_SPINLOCK(pstore_lock); 
struct pstore_info *psinfo;



static char *backend;

static char *compress =

#ifdef CONFIG_PSTORE_COMPRESS_DEFAULT

		CONFIG_PSTORE_COMPRESS_DEFAULT;

#else

		NULL;

#endif



/* Compression parameters */

#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
@@ -84,7 +90,11 @@ static char *backend; 
#define WINDOW_BITS 12

#define MEM_LEVEL 4

static struct z_stream_s stream;

#else

#endif

#if defined(CONFIG_PSTORE_LZO_COMPRESS)   || \

    defined(CONFIG_PSTORE_LZ4_COMPRESS)   || \

    defined(CONFIG_PSTORE_LZ4HC_COMPRESS) || \

    defined(CONFIG_PSTORE_842_COMPRESS)

static unsigned char *workspace;

#endif
@@ -268,14 +278,6 @@ static void free_zlib(void) 
	big_oops_buf = NULL;

	big_oops_buf_sz = 0;

}



static const struct pstore_zbackend backend_zlib = {

	.compress	= compress_zlib,

	.decompress	= decompress_zlib,

	.allocate	= allocate_zlib,

	.free		= free_zlib,

	.name		= "zlib",

};

#endif



#ifdef CONFIG_PSTORE_LZO_COMPRESS
@@ -329,14 +331,6 @@ static void free_lzo(void) 
	big_oops_buf = NULL;

	big_oops_buf_sz = 0;

}



static const struct pstore_zbackend backend_lzo = {

	.compress	= compress_lzo,

	.decompress	= decompress_lzo,

	.allocate	= allocate_lzo,

	.free		= free_lzo,

	.name		= "lzo",

};

#endif



#if defined(CONFIG_PSTORE_LZ4_COMPRESS) || defined(CONFIG_PSTORE_LZ4HC_COMPRESS)
@@ -396,14 +390,6 @@ static void allocate_lz4(void) 
		workspace = NULL;

	}

}



static const struct pstore_zbackend backend_lz4 = {

	.compress	= compress_lz4,

	.decompress	= decompress_lz4,

	.allocate	= allocate_lz4,

	.free		= free_lz4,

	.name		= "lz4",

};

#endif



#ifdef CONFIG_PSTORE_LZ4HC_COMPRESS
@@ -438,14 +424,6 @@ static void allocate_lz4hc(void) 
		workspace = NULL;

	}

}



static const struct pstore_zbackend backend_lz4hc = {

	.compress	= compress_lz4hc,

	.decompress	= decompress_lz4,

	.allocate	= allocate_lz4hc,

	.free		= free_lz4,

	.name		= "lz4hc",

};

#endif



#ifdef CONFIG_PSTORE_842_COMPRESS
@@ -508,30 +486,58 @@ static void free_842(void) 
	big_oops_buf = NULL;

	big_oops_buf_sz = 0;

}

#endif



static const struct pstore_zbackend *zbackend __ro_after_init;



static const struct pstore_zbackend backend_842 = {

static const struct pstore_zbackend zbackends[] = {

#ifdef CONFIG_PSTORE_ZLIB_COMPRESS

	{

		.compress	= compress_zlib,

		.decompress	= decompress_zlib,

		.allocate	= allocate_zlib,

		.free		= free_zlib,

		.name		= "zlib",

	},

#endif

#ifdef CONFIG_PSTORE_LZO_COMPRESS

	{

		.compress	= compress_lzo,

		.decompress	= decompress_lzo,

		.allocate	= allocate_lzo,

		.free		= free_lzo,

		.name		= "lzo",

	},

#endif

#ifdef CONFIG_PSTORE_LZ4_COMPRESS

	{

		.compress	= compress_lz4,

		.decompress	= decompress_lz4,

		.allocate	= allocate_lz4,

		.free		= free_lz4,

		.name		= "lz4",

	},

#endif

#ifdef CONFIG_PSTORE_LZ4HC_COMPRESS

	{

		.compress	= compress_lz4hc,

		.decompress	= decompress_lz4,

		.allocate	= allocate_lz4hc,

		.free		= free_lz4,

		.name		= "lz4hc",

	},

#endif

#ifdef CONFIG_PSTORE_842_COMPRESS

	{

		.compress	= compress_842,

		.decompress	= decompress_842,

		.allocate	= allocate_842,

		.free		= free_842,

		.name		= "842",

};

#endif



static const struct pstore_zbackend *zbackend =

#if defined(CONFIG_PSTORE_ZLIB_COMPRESS)

	&backend_zlib;

#elif defined(CONFIG_PSTORE_LZO_COMPRESS)

	&backend_lzo;

#elif defined(CONFIG_PSTORE_LZ4_COMPRESS)

	&backend_lz4;

#elif defined(CONFIG_PSTORE_LZ4HC_COMPRESS)

	&backend_lz4hc;

#elif defined(CONFIG_PSTORE_842_COMPRESS)

	&backend_842;

#else

	NULL;

	},

#endif

	{ }

};



static int pstore_compress(const void *in, void *out,

			   size_t inlen, size_t outlen)
@@ -553,7 +559,6 @@ static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen) 
static void allocate_buf_for_compression(void)

{

	if (zbackend) {

		pr_info("using %s compression\n", zbackend->name);

		zbackend->allocate();

	} else {

		pr_err("allocate compression buffer error!\n");
@@ -1022,5 +1027,24 @@ static void pstore_timefunc(struct timer_list *unused) 
			  jiffies + msecs_to_jiffies(pstore_update_ms));

}



void __init pstore_choose_compression(void)

{

	const struct pstore_zbackend *step;



	if (!compress)

		return;



	for (step = zbackends; step->name; step++) {

		if (!strcmp(compress, step->name)) {

			zbackend = step;

			pr_info("using %s compression\n", zbackend->name);

			return;

		}

	}

}



module_param(compress, charp, 0444);

MODULE_PARM_DESC(compress, "Pstore compression to use");



module_param(backend, charp, 0444);

MODULE_PARM_DESC(backend, "Pstore backend to use");