From 7684bd334d9d4ca4f09873e88d9c0131a2cf6c3b Mon Sep 17 00:00:00 2001 From: Peng Wang Date: Tue, 30 Oct 2018 15:52:34 +0800 Subject: pstore: Avoid duplicate call of persistent_ram_zap() When initialing a prz, if invalid data is found (no PERSISTENT_RAM_SIG), the function call path looks like this: ramoops_init_prz -> persistent_ram_new -> persistent_ram_post_init -> persistent_ram_zap persistent_ram_zap As we can see, persistent_ram_zap() is called twice. We can avoid this by adding an option to persistent_ram_new(), and only call persistent_ram_zap() when it is needed. Signed-off-by: Peng Wang [kees: minor tweak to exit path and commit log] Signed-off-by: Kees Cook --- include/linux/pstore_ram.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/pstore_ram.h') diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index 602d64725222..6e94980357d2 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -30,6 +30,7 @@ * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required. */ #define PRZ_FLAG_NO_LOCK BIT(0) +#define PRZ_FLAG_ZAP_OLD BIT(1) struct persistent_ram_buffer; struct rs_control; -- cgit v1.2.3 From c208f7d4b037e1c71e5c839bb5dfcc3e0df19890 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 1 Nov 2018 15:11:47 -0700 Subject: pstore/ram: Add kern-doc for struct persistent_ram_zone The struct persistent_ram_zone wasn't well documented. This adds kern-doc for it. Signed-off-by: Kees Cook --- fs/pstore/ram_core.c | 10 ++++++++++ include/linux/pstore_ram.h | 46 +++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 53 insertions(+), 3 deletions(-) (limited to 'include/linux/pstore_ram.h') diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 62830734deee..3e9e3ba4fb07 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -29,6 +29,16 @@ #include #include +/** + * 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 + */ struct persistent_ram_buffer { uint32_t sig; atomic_t start; diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index 6e94980357d2..5d10ad51c1c4 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -30,6 +30,10 @@ * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required. */ #define PRZ_FLAG_NO_LOCK BIT(0) +/* + * If a PRZ should only have a single-boot lifetime, this marks it as + * getting wiped after its contents get copied out after boot. + */ #define PRZ_FLAG_ZAP_OLD BIT(1) struct persistent_ram_buffer; @@ -43,17 +47,53 @@ struct persistent_ram_ecc_info { uint16_t *par; }; +/** + * struct persistent_ram_zone - Details of a persistent RAM zone (PRZ) + * used as a pstore backend + * + * @paddr: physical address of the mapped RAM area + * @size: size of mapping + * @label: unique name of this PRZ + * @flags: holds PRZ_FLAGS_* bits + * + * @buffer_lock: + * locks access to @buffer "size" bytes and "start" offset + * @buffer: + * pointer to actual RAM area managed by this PRZ + * @buffer_size: + * bytes in @buffer->data (not including any trailing ECC bytes) + * + * @par_buffer: + * pointer into @buffer->data containing ECC bytes for @buffer->data + * @par_header: + * pointer into @buffer->data containing ECC bytes for @buffer header + * (i.e. all fields up to @data) + * @rs_decoder: + * RSLIB instance for doing ECC calculations + * @corrected_bytes: + * ECC corrected bytes accounting since boot + * @bad_blocks: + * ECC uncorrectable bytes accounting since boot + * @ecc_info: + * ECC configuration details + * + * @old_log: + * saved copy of @buffer->data prior to most recent wipe + * @old_log_size: + * bytes contained in @old_log + * + */ struct persistent_ram_zone { phys_addr_t paddr; size_t size; void *vaddr; char *label; - struct persistent_ram_buffer *buffer; - size_t buffer_size; u32 flags; + raw_spinlock_t buffer_lock; + struct persistent_ram_buffer *buffer; + size_t buffer_size; - /* ECC correction */ char *par_buffer; char *par_header; struct rs_control *rs_decoder; -- cgit v1.2.3 From f0f23e5469dc80b482d985898a930be0e249a162 Mon Sep 17 00:00:00 2001 From: "Joel Fernandes (Google)" Date: Sat, 3 Nov 2018 16:38:16 -0700 Subject: pstore: Map PSTORE_TYPE_* to strings In later patches we will need to map types to names, so create a constant table for that which can also be used in different parts of old and new code. This saves the type in the PRZ which will be useful in later patches. Instead of having an explicit PSTORE_TYPE_UNKNOWN, just use ..._MAX. This includes removing the now redundant filename templates which can use a single format string. Also, there's no reason to limit the "is it still compressed?" test to only PSTORE_TYPE_DMESG when building the pstorefs filename. Records are zero-initialized, so a backend would need to have explicitly set compressed=1. Signed-off-by: Joel Fernandes (Google) Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- drivers/acpi/apei/erst.c | 2 +- fs/pstore/inode.c | 51 ++++------------------------------------------ fs/pstore/platform.c | 37 +++++++++++++++++++++++++++++++++ fs/pstore/ram.c | 4 +++- include/linux/pstore.h | 17 +++++++++++++--- include/linux/pstore_ram.h | 3 +++ 6 files changed, 62 insertions(+), 52 deletions(-) (limited to 'include/linux/pstore_ram.h') diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c index 3c5ea7cb693e..a5e1d963208e 100644 --- a/drivers/acpi/apei/erst.c +++ b/drivers/acpi/apei/erst.c @@ -1035,7 +1035,7 @@ skip: CPER_SECTION_TYPE_MCE) == 0) record->type = PSTORE_TYPE_MCE; else - record->type = PSTORE_TYPE_UNKNOWN; + record->type = PSTORE_TYPE_MAX; if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP) record->time.tv_sec = rcd->hdr.timestamp; diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 8cf2218b46a7..c60ee46f3e39 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -335,53 +335,10 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) goto fail_alloc; private->record = record; - switch (record->type) { - case PSTORE_TYPE_DMESG: - scnprintf(name, sizeof(name), "dmesg-%s-%llu%s", - record->psi->name, record->id, - record->compressed ? ".enc.z" : ""); - break; - case PSTORE_TYPE_CONSOLE: - scnprintf(name, sizeof(name), "console-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_FTRACE: - scnprintf(name, sizeof(name), "ftrace-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_MCE: - scnprintf(name, sizeof(name), "mce-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_PPC_RTAS: - scnprintf(name, sizeof(name), "rtas-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_PPC_OF: - scnprintf(name, sizeof(name), "powerpc-ofw-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_PPC_COMMON: - scnprintf(name, sizeof(name), "powerpc-common-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_PMSG: - scnprintf(name, sizeof(name), "pmsg-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_PPC_OPAL: - scnprintf(name, sizeof(name), "powerpc-opal-%s-%llu", - record->psi->name, record->id); - break; - case PSTORE_TYPE_UNKNOWN: - scnprintf(name, sizeof(name), "unknown-%s-%llu", - record->psi->name, record->id); - break; - default: - scnprintf(name, sizeof(name), "type%d-%s-%llu", - record->type, record->psi->name, record->id); - break; - } + scnprintf(name, sizeof(name), "%s-%s-%llu%s", + pstore_type_to_name(record->type), + record->psi->name, record->id, + record->compressed ? ".enc.z" : ""); dentry = d_alloc_name(root, name); if (!dentry) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 32340e7dd6a5..2387cb74f729 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -59,6 +59,19 @@ MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content " "enabling this option is not safe, it may lead to further " "corruption on Oopses)"); +/* Names should be in the same order as the enum pstore_type_id */ +static const char * const pstore_type_names[] = { + "dmesg", + "mce", + "console", + "ftrace", + "rtas", + "powerpc-ofw", + "powerpc-common", + "pmsg", + "powerpc-opal", +}; + static int pstore_new_entry; static void pstore_timefunc(struct timer_list *); @@ -104,6 +117,30 @@ void pstore_set_kmsg_bytes(int bytes) /* Tag each group of saved records with a sequence number */ static int oopscount; +const char *pstore_type_to_name(enum pstore_type_id type) +{ + BUILD_BUG_ON(ARRAY_SIZE(pstore_type_names) != PSTORE_TYPE_MAX); + + if (WARN_ON_ONCE(type >= PSTORE_TYPE_MAX)) + return "unknown"; + + return pstore_type_names[type]; +} +EXPORT_SYMBOL_GPL(pstore_type_to_name); + +enum pstore_type_id pstore_name_to_type(const char *name) +{ + int i; + + for (i = 0; i < PSTORE_TYPE_MAX; i++) { + if (!strcmp(pstore_type_names[i], name)) + return i; + } + + return PSTORE_TYPE_MAX; +} +EXPORT_SYMBOL_GPL(pstore_name_to_type); + static const char *get_reason_str(enum kmsg_dump_reason reason) { switch (reason) { diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 10ac4d23c423..b174d0fc009f 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -611,6 +611,7 @@ static int ramoops_init_przs(const char *name, goto fail; } *paddr += zone_sz; + prz_ar[i]->type = pstore_name_to_type(name); } *przs = prz_ar; @@ -650,6 +651,7 @@ static int ramoops_init_prz(const char *name, } *paddr += sz; + (*prz)->type = pstore_name_to_type(name); return 0; } @@ -785,7 +787,7 @@ static int ramoops_probe(struct platform_device *pdev) dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size - cxt->pmsg_size; - err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr, + err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr, dump_mem_sz, cxt->record_size, &cxt->max_dump_cnt, 0, 0); if (err) diff --git a/include/linux/pstore.h b/include/linux/pstore.h index f46e5df76b58..a9ec285d85d1 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -32,21 +32,32 @@ struct module; -/* pstore record types (see fs/pstore/inode.c for filename templates) */ +/* + * pstore record types (see fs/pstore/platform.c for pstore_type_names[]) + * These values may be written to storage (see EFI vars backend), so + * they are kind of an ABI. Be careful changing the mappings. + */ enum pstore_type_id { + /* Frontend storage types */ PSTORE_TYPE_DMESG = 0, PSTORE_TYPE_MCE = 1, PSTORE_TYPE_CONSOLE = 2, PSTORE_TYPE_FTRACE = 3, - /* PPC64 partition types */ + + /* PPC64-specific partition types */ PSTORE_TYPE_PPC_RTAS = 4, PSTORE_TYPE_PPC_OF = 5, PSTORE_TYPE_PPC_COMMON = 6, PSTORE_TYPE_PMSG = 7, PSTORE_TYPE_PPC_OPAL = 8, - PSTORE_TYPE_UNKNOWN = 255 + + /* End of the list */ + PSTORE_TYPE_MAX }; +const char *pstore_type_to_name(enum pstore_type_id type); +enum pstore_type_id pstore_name_to_type(const char *name); + struct pstore_info; /** * struct pstore_record - details of a pstore record entry diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index 5d10ad51c1c4..337971c41980 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -22,6 +22,7 @@ #include #include #include +#include #include /* @@ -54,6 +55,7 @@ struct persistent_ram_ecc_info { * @paddr: physical address of the mapped RAM area * @size: size of mapping * @label: unique name of this PRZ + * @type: frontend type for this PRZ * @flags: holds PRZ_FLAGS_* bits * * @buffer_lock: @@ -88,6 +90,7 @@ struct persistent_ram_zone { size_t size; void *vaddr; char *label; + enum pstore_type_id type; u32 flags; raw_spinlock_t buffer_lock; -- cgit v1.2.3