diff options
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/Kconfig | 100 | ||||
| -rw-r--r-- | fs/pstore/inode.c | 6 | ||||
| -rw-r--r-- | fs/pstore/platform.c | 353 | ||||
| -rw-r--r-- | fs/pstore/ram.c | 11 | ||||
| -rw-r--r-- | fs/pstore/ram_core.c | 17 |
5 files changed, 139 insertions, 348 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/inode.c b/fs/pstore/inode.c index ffbadb8b3032..585360706b33 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -54,7 +54,7 @@ static void free_pstore_private(struct pstore_private *private) if (!private) return; if (private->record) { - kfree(private->record->buf); + kvfree(private->record->buf); kfree(private->record->priv); kfree(private->record); } @@ -223,7 +223,7 @@ static struct inode *pstore_get_inode(struct super_block *sb) struct inode *inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); - inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); + inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode); } return inode; } @@ -390,7 +390,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) inode->i_private = private; if (record->time.tv_sec) - inode->i_mtime = inode->i_ctime = record->time; + inode->i_mtime = inode_set_ctime_to_ts(inode, record->time); d_add(dentry, inode); diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index cbc0b468c1ab..62356d542ef6 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -14,24 +14,17 @@ #include <linux/init.h> #include <linux/kmsg_dump.h> #include <linux/console.h> +#include <linux/mm.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> #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" @@ -80,12 +73,21 @@ 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"); @@ -94,16 +96,9 @@ 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; - -struct pstore_zbackend { - int (*zbufsize)(size_t size); - const char *name; -}; +static void *compress_workspace; static char *big_oops_buf; -static size_t big_oops_buf_sz; void pstore_set_kmsg_bytes(int bytes) { @@ -168,206 +163,89 @@ 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) { + 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; + + 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 outlen; + return zstream.total_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("Unknown compression: %s\n", zbackend->name); + /* Skip if not built-in or compression disabled. */ + if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !compress || + !strcmp(compress, "none")) { + compress = NULL; return; } - size = zbackend->zbufsize(psinfo->bufsize); - if (size <= 0) { - pr_err("Invalid compression size for %s: %d\n", - zbackend->name, size); - return; + if (strcmp(compress, "deflate")) { + pr_err("Unsupported compression '%s', falling back to deflate\n", + compress); + compress = "deflate"; } - 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 = kvzalloc(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); - if (IS_ERR_OR_NULL(ctx)) { - kfree(buf); - pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name, - PTR_ERR(ctx)); + compress_workspace = + vmalloc(zlib_deflate_workspacesize(MAX_WBITS, DEF_MEM_LEVEL)); + if (!compress_workspace) { + pr_err("Failed to allocate zlib deflate workspace\n"); + kvfree(buf); 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) { - 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; - 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; + kvfree(big_oops_buf); + big_oops_buf = NULL; } void pstore_record_init(struct pstore_record *record, @@ -426,13 +304,8 @@ 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 +326,8 @@ 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; @@ -549,7 +422,7 @@ static int pstore_write_user_compat(struct pstore_record *record, if (record->buf) return -EINVAL; - record->buf = memdup_user(buf, record->size); + record->buf = vmemdup_user(buf, record->size); if (IS_ERR(record->buf)) { ret = PTR_ERR(record->buf); goto out; @@ -557,7 +430,7 @@ static int pstore_write_user_compat(struct pstore_record *record, ret = record->psi->write(record); - kfree(record->buf); + kvfree(record->buf); out: record->buf = NULL; @@ -681,7 +554,8 @@ 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; @@ -697,40 +571,50 @@ 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. */ - unzipped_len = big_oops_buf_sz; - workspace = kmalloc(unzipped_len + record->ecc_notice_size, - GFP_KERNEL); + workspace = kvzalloc(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); - kfree(workspace); + 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); + kvfree(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); /* Copy decompressed contents into an minimum-sized allocation. */ - unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size, - GFP_KERNEL); - kfree(workspace); + unzipped = kvmemdup(workspace, unzipped_len + record->ecc_notice_size, + GFP_KERNEL); + kvfree(workspace); if (!unzipped) return; /* Swap out compressed contents with decompressed contents. */ - kfree(record->buf); + kvfree(record->buf); record->buf = unzipped; record->size = unzipped_len; record->compressed = false; @@ -747,10 +631,17 @@ 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; @@ -779,11 +670,11 @@ 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. */ - kfree(record->buf); + kvfree(record->buf); kfree(record->priv); kfree(record); if (rc != -EEXIST || !quiet) @@ -795,6 +686,12 @@ 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); @@ -818,34 +715,10 @@ 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, - * initialize compression now. - */ - allocate_buf_for_compression(); - ret = pstore_init_fs(); if (ret) free_buf_for_compression(); diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 2f625e1fa8d8..d36702c7ab3c 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -20,6 +20,7 @@ #include <linux/compiler.h> #include <linux/of.h> #include <linux/of_address.h> +#include <linux/mm.h> #include "internal.h" #include "ram_internal.h" @@ -268,7 +269,7 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) /* ECC correction notice */ record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0); - record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL); + record->buf = kvzalloc(size + record->ecc_notice_size + 1, GFP_KERNEL); if (record->buf == NULL) { size = -ENOMEM; goto out; @@ -282,7 +283,7 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) out: if (free_prz) { - kfree(prz->old_log); + kvfree(prz->old_log); kfree(prz); } @@ -833,7 +834,7 @@ static int ramoops_probe(struct platform_device *pdev) */ if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) { cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size; - cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL); + cxt->pstore.buf = kvzalloc(cxt->pstore.bufsize, GFP_KERNEL); if (!cxt->pstore.buf) { pr_err("cannot allocate pstore crash dump buffer\n"); err = -ENOMEM; @@ -866,7 +867,7 @@ static int ramoops_probe(struct platform_device *pdev) return 0; fail_buf: - kfree(cxt->pstore.buf); + kvfree(cxt->pstore.buf); fail_clear: cxt->pstore.bufsize = 0; fail_init: @@ -881,7 +882,7 @@ static void ramoops_remove(struct platform_device *pdev) pstore_unregister(&cxt->pstore); - kfree(cxt->pstore.buf); + kvfree(cxt->pstore.buf); cxt->pstore.bufsize = 0; ramoops_free_przs(cxt); diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 85aaf0fc6d7d..650e437b55e6 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -17,6 +17,7 @@ #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/vmalloc.h> +#include <linux/mm.h> #include <asm/page.h> #include "ram_internal.h" @@ -24,12 +25,10 @@ /** * struct persistent_ram_buffer - persistent circular RAM buffer * - * @sig: - * signature to indicate header (PERSISTENT_RAM_SIG xor PRZ-type value) - * @start: - * offset into @data where the beginning of the stored bytes begin - * @size: - * number of valid bytes stored in @data + * @sig: Signature to indicate header (PERSISTENT_RAM_SIG xor PRZ-type value) + * @start: First valid byte in the buffer. + * @size: Number of valid bytes in the buffer. + * @data: The contents of the buffer. */ struct persistent_ram_buffer { uint32_t sig; @@ -301,7 +300,7 @@ void persistent_ram_save_old(struct persistent_ram_zone *prz) if (!prz->old_log) { persistent_ram_ecc_old(prz); - prz->old_log = kmalloc(size, GFP_KERNEL); + prz->old_log = kvzalloc(size, GFP_KERNEL); } if (!prz->old_log) { pr_err("failed to allocate buffer\n"); @@ -385,7 +384,7 @@ void *persistent_ram_old(struct persistent_ram_zone *prz) void persistent_ram_free_old(struct persistent_ram_zone *prz) { - kfree(prz->old_log); + kvfree(prz->old_log); prz->old_log = NULL; prz->old_log_size = 0; } @@ -519,7 +518,7 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig, sig ^= PERSISTENT_RAM_SIG; if (prz->buffer->sig == sig) { - if (buffer_size(prz) == 0) { + if (buffer_size(prz) == 0 && buffer_start(prz) == 0) { pr_debug("found existing empty buffer\n"); return 0; } |