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Commit 95047b05 authored by Kees Cook's avatar Kees Cook
Browse files

pstore: Refactor compression initialization 



This refactors compression initialization slightly to better handle
getting potentially called twice (via early pstore_register() calls
and later pstore_init()) and improves the comments and reporting to be
more verbose.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Tested-by: default avatarGuenter Roeck <groeck@chromium.org>
parent 41603165

fs/pstore/platform.c

+33 −15
Original line number Diff line number Diff line
@@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out, 


static void allocate_buf_for_compression(void)

{

	struct crypto_comp *ctx;

	int size;

	char *buf;



	/* Skip if not built-in or compression backend not selected yet. */

	if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)

		return;



	/* Skip if no pstore backend yet or compression init already done. */

	if (!psinfo || tfm)

		return;



	if (!crypto_has_comp(zbackend->name, 0, 0)) {

		pr_err("No %s compression\n", zbackend->name);

		pr_err("Unknown compression: %s\n", zbackend->name);

		return;

	}



	big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);

	if (big_oops_buf_sz <= 0)

	size = zbackend->zbufsize(psinfo->bufsize);

	if (size <= 0) {

		pr_err("Invalid compression size for %s: %d\n",

		       zbackend->name, size);

		return;

	}



	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);

	if (!big_oops_buf) {

		pr_err("allocate compression buffer error!\n");

	buf = kmalloc(size, GFP_KERNEL);

	if (!buf) {

		pr_err("Failed %d byte compression buffer allocation for: %s\n",

		       size, zbackend->name);

		return;

	}



	tfm = crypto_alloc_comp(zbackend->name, 0, 0);

	if (IS_ERR_OR_NULL(tfm)) {

		kfree(big_oops_buf);

		big_oops_buf = NULL;

		pr_err("crypto_alloc_comp() failed!\n");

	ctx = crypto_alloc_comp(zbackend->name, 0, 0);

	if (IS_ERR_OR_NULL(ctx)) {

		kfree(buf);

		pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,

		       PTR_ERR(ctx));

		return;

	}



	/* A non-NULL big_oops_buf indicates compression is available. */

	tfm = ctx;

	big_oops_buf_sz = size;

	big_oops_buf = buf;



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

}



static void free_buf_for_compression(void)

{

	if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))

	if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm)

		crypto_free_comp(tfm);

	kfree(big_oops_buf);

	big_oops_buf = NULL;
@@ -774,7 +794,6 @@ void __init pstore_choose_compression(void) 
	for (step = zbackends; step->name; step++) {

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

			zbackend = step;

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

			return;

		}

	}
@@ -791,7 +810,6 @@ static int __init pstore_init(void) 
	 * initialize compression because crypto was not ready. If so,

	 * initialize compression now.

	 */

	if (psinfo && !tfm)

	allocate_buf_for_compression();



	ret = pstore_init_fs();