diff options
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/Kconfig | 100 | ||||
| -rw-r--r-- | fs/pstore/platform.c | 136 |
2 files changed, 97 insertions, 139 deletions
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index c49d554cc9ae..3acc38600cd1 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 13fd1a297846..aaa5e4e66db4 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) - return; - - /* Skip if no pstore backend yet or compression init already done. */ - if (!psinfo || tfm) + /* Skip if not built-in or compression disabled. */ + if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !compress || + !strcmp(compress, "none")) { + compress = NULL; 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(); |