* [PATCH v3 1/2] pstore: Remove worst-case compression size logic
2023-07-12 16:23 [PATCH v3 0/2] pstore: Replace crypto API compression with zlib calls Ard Biesheuvel
@ 2023-07-12 16:23 ` Ard Biesheuvel
2023-07-13 6:59 ` Eric Biggers
2023-07-12 16:23 ` [PATCH v3 2/2] pstore: Replace crypto API compression with zlib_deflate library calls Ard Biesheuvel
2023-07-13 17:37 ` [PATCH v3 0/2] pstore: Replace crypto API compression with zlib calls Kees Cook
2 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2023-07-12 16:23 UTC (permalink / raw)
To: linux-hardening
Cc: Ard Biesheuvel, Kees Cook, Guilherme G. Piccoli, Eric Biggers
The worst case compression size used by pstore gives an upper bound for
how much the data might inadvertently *grow* due to encapsulation
overhead if the input is not compressible at all.
Given that pstore records have individual 'compressed' flags, we can
simply store the uncompressed data if compressing it would end up using
more space, making the worst case identical to the uncompressed case.
This means we can just drop all the elaborate logic that reasons about
upper bounds for each individual compression algorithm, and just store
the uncompressed data directly if compression fails for any reason.
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
fs/pstore/platform.c | 206 ++------------------
1 file changed, 19 insertions(+), 187 deletions(-)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index cbc0b468c1ab6ca1..13fd1a297846535a 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -16,15 +16,6 @@
#include <linux/console.h>
#include <linux/module.h>
#include <linux/pstore.h>
-#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
-#include <linux/lzo.h>
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
-#include <linux/lz4.h>
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
-#include <linux/zstd.h>
-#endif
#include <linux/crypto.h>
#include <linux/string.h>
#include <linux/timer.h>
@@ -97,13 +88,7 @@ MODULE_PARM_DESC(kmsg_bytes, "amount of kernel log to snapshot (in bytes)");
/* Compression parameters */
static struct crypto_comp *tfm;
-struct pstore_zbackend {
- int (*zbufsize)(size_t size);
- const char *name;
-};
-
static char *big_oops_buf;
-static size_t big_oops_buf_sz;
void pstore_set_kmsg_bytes(int bytes)
{
@@ -168,105 +153,6 @@ static bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
}
}
-#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
-static int zbufsize_deflate(size_t size)
-{
- size_t cmpr;
-
- switch (size) {
- /* buffer range for efivars */
- case 1000 ... 2000:
- cmpr = 56;
- break;
- case 2001 ... 3000:
- cmpr = 54;
- break;
- case 3001 ... 3999:
- cmpr = 52;
- break;
- /* buffer range for nvram, erst */
- case 4000 ... 10000:
- cmpr = 45;
- break;
- default:
- cmpr = 60;
- break;
- }
-
- return (size * 100) / cmpr;
-}
-#endif
-
-#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
-static int zbufsize_lzo(size_t size)
-{
- return lzo1x_worst_compress(size);
-}
-#endif
-
-#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
-static int zbufsize_lz4(size_t size)
-{
- return LZ4_compressBound(size);
-}
-#endif
-
-#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
-static int zbufsize_842(size_t size)
-{
- return size;
-}
-#endif
-
-#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
-static int zbufsize_zstd(size_t size)
-{
- return zstd_compress_bound(size);
-}
-#endif
-
-static const struct pstore_zbackend *zbackend __ro_after_init;
-
-static const struct pstore_zbackend zbackends[] = {
-#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
- {
- .zbufsize = zbufsize_deflate,
- .name = "deflate",
- },
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
- {
- .zbufsize = zbufsize_lzo,
- .name = "lzo",
- },
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS)
- {
- .zbufsize = zbufsize_lz4,
- .name = "lz4",
- },
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
- {
- .zbufsize = zbufsize_lz4,
- .name = "lz4hc",
- },
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
- {
- .zbufsize = zbufsize_842,
- .name = "842",
- },
-#endif
-#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
- {
- .zbufsize = zbufsize_zstd,
- .name = "zstd",
- },
-#endif
- { }
-};
-
static int pstore_compress(const void *in, void *out,
unsigned int inlen, unsigned int outlen)
{
@@ -287,50 +173,46 @@ static int pstore_compress(const 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)
+ if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !compress)
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("Unknown compression: %s\n", zbackend->name);
+ if (!crypto_has_comp(compress, 0, 0)) {
+ pr_err("Unknown compression: %s\n", compress);
return;
}
- size = zbackend->zbufsize(psinfo->bufsize);
- if (size <= 0) {
- pr_err("Invalid compression size for %s: %d\n",
- zbackend->name, size);
- return;
- }
-
- buf = kmalloc(size, GFP_KERNEL);
+ /*
+ * The compression buffer only needs to be as large as the maximum
+ * uncompressed record size, since any record that would be expanded by
+ * compression is just stored uncompressed.
+ */
+ buf = kmalloc(psinfo->bufsize, GFP_KERNEL);
if (!buf) {
- pr_err("Failed %d byte compression buffer allocation for: %s\n",
- size, zbackend->name);
+ pr_err("Failed %zu byte compression buffer allocation for: %s\n",
+ psinfo->bufsize, compress);
return;
}
- ctx = crypto_alloc_comp(zbackend->name, 0, 0);
+ ctx = crypto_alloc_comp(compress, 0, 0);
if (IS_ERR_OR_NULL(ctx)) {
kfree(buf);
- pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
+ pr_err("crypto_alloc_comp('%s') failed: %ld\n", compress,
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 crash dump compression: %s\n", zbackend->name);
+ pr_info("Using crash dump compression: %s\n", compress);
}
static void free_buf_for_compression(void)
@@ -341,33 +223,6 @@ static void free_buf_for_compression(void)
}
kfree(big_oops_buf);
big_oops_buf = NULL;
- big_oops_buf_sz = 0;
-}
-
-/*
- * Called when compression fails, since the printk buffer
- * would be fetched for compression calling it again when
- * compression fails would have moved the iterator of
- * printk buffer which results in fetching old contents.
- * Copy the recent messages from big_oops_buf to psinfo->buf
- */
-static size_t copy_kmsg_to_buffer(int hsize, size_t len)
-{
- size_t total_len;
- size_t diff;
-
- total_len = hsize + len;
-
- if (total_len > psinfo->bufsize) {
- diff = total_len - psinfo->bufsize + hsize;
- memcpy(psinfo->buf, big_oops_buf, hsize);
- memcpy(psinfo->buf + hsize, big_oops_buf + diff,
- psinfo->bufsize - hsize);
- total_len = psinfo->bufsize;
- } else
- memcpy(psinfo->buf, big_oops_buf, total_len);
-
- return total_len;
}
void pstore_record_init(struct pstore_record *record,
@@ -426,13 +281,8 @@ static void pstore_dump(struct kmsg_dumper *dumper,
record.part = part;
record.buf = psinfo->buf;
- if (big_oops_buf) {
- dst = big_oops_buf;
- dst_size = big_oops_buf_sz;
- } else {
- dst = psinfo->buf;
- dst_size = psinfo->bufsize;
- }
+ dst = big_oops_buf ?: psinfo->buf;
+ dst_size = psinfo->bufsize;
/* Write dump header. */
header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why,
@@ -453,8 +303,8 @@ static void pstore_dump(struct kmsg_dumper *dumper,
record.compressed = true;
record.size = zipped_len;
} else {
- record.size = copy_kmsg_to_buffer(header_size,
- dump_size);
+ record.size = header_size + dump_size;
+ memcpy(psinfo->buf, dst, record.size);
}
} else {
record.size = header_size + dump_size;
@@ -703,8 +553,7 @@ static void decompress_record(struct pstore_record *record)
}
/* Allocate enough space to hold max decompression and ECC. */
- unzipped_len = big_oops_buf_sz;
- workspace = kmalloc(unzipped_len + record->ecc_notice_size,
+ workspace = kmalloc(psinfo->bufsize + record->ecc_notice_size,
GFP_KERNEL);
if (!workspace)
return;
@@ -818,27 +667,10 @@ static void pstore_timefunc(struct timer_list *unused)
pstore_timer_kick();
}
-static 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;
- return;
- }
- }
-}
-
static int __init pstore_init(void)
{
int ret;
- pstore_choose_compression();
-
/*
* Check if any pstore backends registered earlier but did not
* initialize compression because crypto was not ready. If so,
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/2] pstore: Replace crypto API compression with zlib_deflate library calls
2023-07-12 16:23 [PATCH v3 0/2] pstore: Replace crypto API compression with zlib calls Ard Biesheuvel
2023-07-12 16:23 ` [PATCH v3 1/2] pstore: Remove worst-case compression size logic Ard Biesheuvel
@ 2023-07-12 16:23 ` Ard Biesheuvel
2023-07-13 7:00 ` Eric Biggers
2023-07-13 17:37 ` [PATCH v3 0/2] pstore: Replace crypto API compression with zlib calls Kees Cook
2 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2023-07-12 16:23 UTC (permalink / raw)
To: linux-hardening
Cc: Ard Biesheuvel, Kees Cook, Guilherme G. Piccoli, Eric Biggers
Pstore supports compression using a variety of algorithms exposed by the
crypto API. This uses the deprecated comp (as opposed to scomp/acomp)
API, and so we should stop using that, and either move to the new API,
or switch to a different approach entirely.
Given that we only compress ASCII text in pstore, and considering that
this happens when the system is likely to be in an unstable state, the
flexibility that the complex crypto API provides does not outweigh its
impact on the risk that we might encounter additional problems when
trying to commit the kernel log contents to the pstore backend.
So let's switch [back] to the zlib deflate library API, and remove all
the complexity that really has no place in a low-level diagnostic
facility. Note that, while more modern compression algorithms have been
added to the kernel in recent years, the code size of zlib deflate is
substantially smaller than, e.g., zstd, while its performance in terms
of compression ratio is comparable for ASCII text, and speed is deemed
irrelevant in this context.
Note that this means that compressed pstore records may no longer be
accessible after a kernel upgrade, but this has never been part of the
contract. (The choice of compression algorithm is not stored in the
pstore records either)
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
fs/pstore/Kconfig | 100 ++------------
fs/pstore/platform.c | 136 +++++++++++++-------
2 files changed, 97 insertions(+), 139 deletions(-)
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index c49d554cc9ae9f80..3acc38600cd1a2d0 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -1,7 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
config PSTORE
tristate "Persistent store support"
- select CRYPTO if PSTORE_COMPRESS
default n
help
This option enables generic access to platform level
@@ -22,99 +21,18 @@ config PSTORE_DEFAULT_KMSG_BYTES
Defines default size of pstore kernel log storage.
Can be enlarged if needed, not recommended to shrink it.
-config PSTORE_DEFLATE_COMPRESS
- tristate "DEFLATE (ZLIB) compression"
- default y
- depends on PSTORE
- select CRYPTO_DEFLATE
- help
- This option enables DEFLATE (also known as ZLIB) compression
- algorithm support.
-
-config PSTORE_LZO_COMPRESS
- tristate "LZO compression"
- depends on PSTORE
- select CRYPTO_LZO
- help
- This option enables LZO compression algorithm support.
-
-config PSTORE_LZ4_COMPRESS
- tristate "LZ4 compression"
- depends on PSTORE
- select CRYPTO_LZ4
- help
- This option enables LZ4 compression algorithm support.
-
-config PSTORE_LZ4HC_COMPRESS
- tristate "LZ4HC compression"
- depends on PSTORE
- select CRYPTO_LZ4HC
- help
- This option enables LZ4HC (high compression) mode algorithm.
-
-config PSTORE_842_COMPRESS
- bool "842 compression"
- depends on PSTORE
- select CRYPTO_842
- help
- This option enables 842 compression algorithm support.
-
-config PSTORE_ZSTD_COMPRESS
- bool "zstd compression"
- depends on PSTORE
- select CRYPTO_ZSTD
- help
- This option enables zstd compression algorithm support.
-
config PSTORE_COMPRESS
- def_bool y
+ bool "Pstore compression (deflate)"
depends on PSTORE
- depends on PSTORE_DEFLATE_COMPRESS || PSTORE_LZO_COMPRESS || \
- PSTORE_LZ4_COMPRESS || PSTORE_LZ4HC_COMPRESS || \
- PSTORE_842_COMPRESS || PSTORE_ZSTD_COMPRESS
-
-choice
- prompt "Default pstore compression algorithm"
- depends on PSTORE_COMPRESS
+ select ZLIB_INFLATE
+ select ZLIB_DEFLATE
+ default y
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 6 compression algorithms:
- deflate, lzo, lz4, lz4hc, 842 and zstd.
-
- The default compression algorithm is deflate.
-
- config PSTORE_DEFLATE_COMPRESS_DEFAULT
- bool "deflate" if PSTORE_DEFLATE_COMPRESS
-
- config PSTORE_LZO_COMPRESS_DEFAULT
- bool "lzo" if PSTORE_LZO_COMPRESS
-
- config PSTORE_LZ4_COMPRESS_DEFAULT
- bool "lz4" if PSTORE_LZ4_COMPRESS
-
- config PSTORE_LZ4HC_COMPRESS_DEFAULT
- bool "lz4hc" if PSTORE_LZ4HC_COMPRESS
-
- config PSTORE_842_COMPRESS_DEFAULT
- bool "842" if PSTORE_842_COMPRESS
-
- config PSTORE_ZSTD_COMPRESS_DEFAULT
- bool "zstd" if PSTORE_ZSTD_COMPRESS
-
-endchoice
-
-config PSTORE_COMPRESS_DEFAULT
- string
- depends on PSTORE_COMPRESS
- default "deflate" if PSTORE_DEFLATE_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
- default "zstd" if PSTORE_ZSTD_COMPRESS_DEFAULT
+ Whether pstore records should be compressed before being written to
+ the backing store. This is implemented using the zlib 'deflate'
+ algorithm, using the library implementation instead of using the full
+ blown crypto API. This reduces the risk of secondary oopses or other
+ problems while pstore is recording panic metadata.
config PSTORE_CONSOLE
bool "Log kernel console messages"
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 13fd1a297846535a..aaa5e4e66db431b3 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -16,13 +16,14 @@
#include <linux/console.h>
#include <linux/module.h>
#include <linux/pstore.h>
-#include <linux/crypto.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/jiffies.h>
+#include <linux/vmalloc.h>
#include <linux/workqueue.h>
+#include <linux/zlib.h>
#include "internal.h"
@@ -71,12 +72,21 @@ static char *backend;
module_param(backend, charp, 0444);
MODULE_PARM_DESC(backend, "specific backend to use");
-static char *compress =
-#ifdef CONFIG_PSTORE_COMPRESS_DEFAULT
- CONFIG_PSTORE_COMPRESS_DEFAULT;
-#else
- NULL;
-#endif
+/*
+ * pstore no longer implements compression via the crypto API, and only
+ * supports zlib deflate compression implemented using the zlib library
+ * interface. This removes additional complexity which is hard to justify for a
+ * diagnostic facility that has to operate in conditions where the system may
+ * have become unstable. Zlib deflate is comparatively small in terms of code
+ * size, and compresses ASCII text comparatively well. In terms of compression
+ * speed, deflate is not the best performer but for recording the log output on
+ * a kernel panic, this is not considered critical.
+ *
+ * The only remaining arguments supported by the compress= module parameter are
+ * 'deflate' and 'none'. To retain compatibility with existing installations,
+ * all other values are logged and replaced with 'deflate'.
+ */
+static char *compress = "deflate";
module_param(compress, charp, 0444);
MODULE_PARM_DESC(compress, "compression to use");
@@ -85,8 +95,7 @@ unsigned long kmsg_bytes = CONFIG_PSTORE_DEFAULT_KMSG_BYTES;
module_param(kmsg_bytes, ulong, 0444);
MODULE_PARM_DESC(kmsg_bytes, "amount of kernel log to snapshot (in bytes)");
-/* Compression parameters */
-static struct crypto_comp *tfm;
+static void *compress_workspace;
static char *big_oops_buf;
@@ -156,36 +165,49 @@ static bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
static int pstore_compress(const void *in, void *out,
unsigned int inlen, unsigned int outlen)
{
+ struct z_stream_s zstream = {
+ .next_in = in,
+ .avail_in = inlen,
+ .next_out = out,
+ .avail_out = outlen,
+ .workspace = compress_workspace,
+ };
int ret;
if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS))
return -EINVAL;
- ret = crypto_comp_compress(tfm, in, inlen, out, &outlen);
- if (ret) {
- pr_err("crypto_comp_compress failed, ret = %d!\n", ret);
- return ret;
- }
+ ret = zlib_deflateInit2(&zstream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
+ -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+ if (ret != Z_OK)
+ return -EINVAL;
- return outlen;
+ ret = zlib_deflate(&zstream, Z_FINISH);
+ if (ret != Z_STREAM_END)
+ return -EINVAL;
+
+ ret = zlib_deflateEnd(&zstream);
+ if (ret != Z_OK)
+ pr_warn_once("zlib_deflateEnd() failed: %d\n", ret);
+
+ return zstream.total_out;
}
static void allocate_buf_for_compression(void)
{
- struct crypto_comp *ctx;
char *buf;
- /* Skip if not built-in or compression backend not selected yet. */
- if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !compress)
+ /* Skip if not built-in or compression disabled. */
+ if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !compress ||
+ !strcmp(compress, "none")) {
+ compress = NULL;
return;
+ }
- /* Skip if no pstore backend yet or compression init already done. */
- if (!psinfo || tfm)
- return;
-
- if (!crypto_has_comp(compress, 0, 0)) {
- pr_err("Unknown compression: %s\n", compress);
- return;
+ if (strcmp(compress, "deflate")) {
+ pr_err("Unsupported compression '%s', falling back to deflate\n",
+ compress);
+ compress = "deflate";
}
/*
@@ -200,16 +222,15 @@ static void allocate_buf_for_compression(void)
return;
}
- ctx = crypto_alloc_comp(compress, 0, 0);
- if (IS_ERR_OR_NULL(ctx)) {
+ compress_workspace =
+ vmalloc(zlib_deflate_workspacesize(MAX_WBITS, DEF_MEM_LEVEL));
+ if (!compress_workspace) {
+ pr_err("Failed to allocate zlib deflate workspace\n");
kfree(buf);
- pr_err("crypto_alloc_comp('%s') failed: %ld\n", compress,
- PTR_ERR(ctx));
return;
}
/* A non-NULL big_oops_buf indicates compression is available. */
- tfm = ctx;
big_oops_buf = buf;
pr_info("Using crash dump compression: %s\n", compress);
@@ -217,10 +238,11 @@ static void allocate_buf_for_compression(void)
static void free_buf_for_compression(void)
{
- if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) {
- crypto_free_comp(tfm);
- tfm = NULL;
+ if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && compress_workspace) {
+ vfree(compress_workspace);
+ compress_workspace = NULL;
}
+
kfree(big_oops_buf);
big_oops_buf = NULL;
}
@@ -531,7 +553,8 @@ void pstore_unregister(struct pstore_info *psi)
}
EXPORT_SYMBOL_GPL(pstore_unregister);
-static void decompress_record(struct pstore_record *record)
+static void decompress_record(struct pstore_record *record,
+ struct z_stream_s *zstream)
{
int ret;
int unzipped_len;
@@ -547,26 +570,37 @@ static void decompress_record(struct pstore_record *record)
}
/* Missing compression buffer means compression was not initialized. */
- if (!big_oops_buf) {
+ if (!zstream->workspace) {
pr_warn("no decompression method initialized!\n");
return;
}
+ ret = zlib_inflateReset(zstream);
+ if (ret != Z_OK) {
+ pr_err("zlib_inflateReset() failed, ret = %d!\n", ret);
+ return;
+ }
+
/* Allocate enough space to hold max decompression and ECC. */
workspace = kmalloc(psinfo->bufsize + record->ecc_notice_size,
GFP_KERNEL);
if (!workspace)
return;
- /* After decompression "unzipped_len" is almost certainly smaller. */
- ret = crypto_comp_decompress(tfm, record->buf, record->size,
- workspace, &unzipped_len);
- if (ret) {
- pr_err("crypto_comp_decompress failed, ret = %d!\n", ret);
+ zstream->next_in = record->buf;
+ zstream->avail_in = record->size;
+ zstream->next_out = workspace;
+ zstream->avail_out = psinfo->bufsize;
+
+ ret = zlib_inflate(zstream, Z_FINISH);
+ if (ret != Z_STREAM_END) {
+ pr_err("zlib_inflate() failed, ret = %d!\n", ret);
kfree(workspace);
return;
}
+ unzipped_len = zstream->total_out;
+
/* Append ECC notice to decompressed buffer. */
memcpy(workspace + unzipped_len, record->buf + record->size,
record->ecc_notice_size);
@@ -596,10 +630,17 @@ void pstore_get_backend_records(struct pstore_info *psi,
{
int failed = 0;
unsigned int stop_loop = 65536;
+ struct z_stream_s zstream = {};
if (!psi || !root)
return;
+ if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && compress) {
+ zstream.workspace = kvmalloc(zlib_inflate_workspacesize(),
+ GFP_KERNEL);
+ zlib_inflateInit2(&zstream, -DEF_WBITS);
+ }
+
mutex_lock(&psi->read_mutex);
if (psi->open && psi->open(psi))
goto out;
@@ -628,7 +669,7 @@ void pstore_get_backend_records(struct pstore_info *psi,
break;
}
- decompress_record(record);
+ decompress_record(record, &zstream);
rc = pstore_mkfile(root, record);
if (rc) {
/* pstore_mkfile() did not take record, so free it. */
@@ -644,6 +685,12 @@ void pstore_get_backend_records(struct pstore_info *psi,
out:
mutex_unlock(&psi->read_mutex);
+ if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && compress) {
+ if (zlib_inflateEnd(&zstream) != Z_OK)
+ pr_warn("zlib_inflateEnd() failed\n");
+ kvfree(zstream.workspace);
+ }
+
if (failed)
pr_warn("failed to create %d record(s) from '%s'\n",
failed, psi->name);
@@ -671,13 +718,6 @@ static int __init pstore_init(void)
{
int ret;
- /*
- * Check if any pstore backends registered earlier but did not
- * initialize compression because crypto was not ready. If so,
- * initialize compression now.
- */
- allocate_buf_for_compression();
-
ret = pstore_init_fs();
if (ret)
free_buf_for_compression();
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread