From 3d6d8d20ec4fd3b256632edb373a9c504724b8a9 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 17 Nov 2011 13:13:29 -0800 Subject: [PATCH 1/2] pstore: pass reason to backend write callback This allows a backend to filter on the dmesg reason as well as the pstore reason. When ramoops is switched to pstore, this is needed since it has no interest in storing non-crash dmesg details. Drop pstore_write() as it has no users, and handling the "reason" here has no obviously correct value. Signed-off-by: Kees Cook Signed-off-by: Tony Luck --- drivers/acpi/apei/erst.c | 6 ++++-- drivers/firmware/efivars.c | 8 +++++--- fs/pstore/platform.c | 30 +----------------------------- include/linux/pstore.h | 12 +++++------- 4 files changed, 15 insertions(+), 41 deletions(-) diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c index 631b9477b99c..6a9e3bad13f4 100644 --- a/drivers/acpi/apei/erst.c +++ b/drivers/acpi/apei/erst.c @@ -934,7 +934,8 @@ static int erst_close_pstore(struct pstore_info *psi); static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, struct timespec *time, char **buf, struct pstore_info *psi); -static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part, +static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason, + u64 *id, unsigned int part, size_t size, struct pstore_info *psi); static int erst_clearer(enum pstore_type_id type, u64 id, struct pstore_info *psi); @@ -1053,7 +1054,8 @@ out: return (rc < 0) ? rc : (len - sizeof(*rcd)); } -static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part, +static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason, + u64 *id, unsigned int part, size_t size, struct pstore_info *psi) { struct cper_pstore_record *rcd = (struct cper_pstore_record *) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index a54a6b972ced..0a53a05a850d 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -495,7 +495,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, return 0; } -static int efi_pstore_write(enum pstore_type_id type, u64 *id, +static int efi_pstore_write(enum pstore_type_id type, + enum kmsg_dump_reason reason, u64 *id, unsigned int part, size_t size, struct pstore_info *psi) { char name[DUMP_NAME_LEN]; @@ -565,7 +566,7 @@ static int efi_pstore_write(enum pstore_type_id type, u64 *id, static int efi_pstore_erase(enum pstore_type_id type, u64 id, struct pstore_info *psi) { - efi_pstore_write(type, &id, (unsigned int)id, 0, psi); + efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi); return 0; } @@ -586,7 +587,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, return -1; } -static int efi_pstore_write(enum pstore_type_id type, u64 *id, +static int efi_pstore_write(enum pstore_type_id type, + enum kmsg_dump_reason reason, u64 *id, unsigned int part, size_t size, struct pstore_info *psi) { return 0; diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 57bbf9078ac8..f146d89179bf 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -122,7 +122,7 @@ static void pstore_dump(struct kmsg_dumper *dumper, memcpy(dst, s1 + s1_start, l1_cpy); memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy); - ret = psinfo->write(PSTORE_TYPE_DMESG, &id, part, + ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part, hsize + l1_cpy + l2_cpy, psinfo); if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) pstore_new_entry = 1; @@ -243,33 +243,5 @@ static void pstore_timefunc(unsigned long dummy) mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL); } -/* - * Call platform driver to write a record to the - * persistent store. - */ -int pstore_write(enum pstore_type_id type, char *buf, size_t size) -{ - u64 id; - int ret; - unsigned long flags; - - if (!psinfo) - return -ENODEV; - - if (size > psinfo->bufsize) - return -EFBIG; - - spin_lock_irqsave(&psinfo->buf_lock, flags); - memcpy(psinfo->buf, buf, size); - ret = psinfo->write(type, &id, 0, size, psinfo); - if (ret == 0 && pstore_is_mounted()) - pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id, psinfo->buf, - size, CURRENT_TIME, psinfo); - spin_unlock_irqrestore(&psinfo->buf_lock, flags); - - return 0; -} -EXPORT_SYMBOL_GPL(pstore_write); - module_param(backend, charp, 0444); MODULE_PARM_DESC(backend, "Pstore backend to use"); diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 2ca8cde5459d..e1461e143be2 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -22,6 +22,9 @@ #ifndef _LINUX_PSTORE_H #define _LINUX_PSTORE_H +#include +#include + /* types */ enum pstore_type_id { PSTORE_TYPE_DMESG = 0, @@ -41,7 +44,8 @@ struct pstore_info { ssize_t (*read)(u64 *id, enum pstore_type_id *type, struct timespec *time, char **buf, struct pstore_info *psi); - int (*write)(enum pstore_type_id type, u64 *id, + int (*write)(enum pstore_type_id type, + enum kmsg_dump_reason reason, u64 *id, unsigned int part, size_t size, struct pstore_info *psi); int (*erase)(enum pstore_type_id type, u64 id, struct pstore_info *psi); @@ -50,18 +54,12 @@ struct pstore_info { #ifdef CONFIG_PSTORE extern int pstore_register(struct pstore_info *); -extern int pstore_write(enum pstore_type_id type, char *buf, size_t size); #else static inline int pstore_register(struct pstore_info *psi) { return -ENODEV; } -static inline int -pstore_write(enum pstore_type_id type, char *buf, size_t size) -{ - return -ENODEV; -} #endif #endif /*_LINUX_PSTORE_H*/ From 2174f6df7891fa331800beb72634c969f017900b Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 18 Nov 2011 13:49:00 -0800 Subject: [PATCH 2/2] pstore: gracefully handle NULL pstore_info functions If a pstore backend doesn't want to support various portions of the pstore interface, it can just leave those functions NULL instead of creating no-op stubs. Signed-off-by: Kees Cook Signed-off-by: Tony Luck --- fs/pstore/inode.c | 3 ++- fs/pstore/platform.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 379a02dc1217..b3b426edb2fd 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -80,7 +80,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry) { struct pstore_private *p = dentry->d_inode->i_private; - p->psi->erase(p->type, p->id, p->psi); + if (p->psi->erase) + p->psi->erase(p->type, p->id, p->psi); return simple_unlink(dir, dentry); } diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index f146d89179bf..9ec22d3b4293 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -207,8 +207,7 @@ void pstore_get_records(int quiet) return; mutex_lock(&psi->read_mutex); - rc = psi->open(psi); - if (rc) + if (psi->open && psi->open(psi)) goto out; while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) { @@ -219,7 +218,8 @@ void pstore_get_records(int quiet) if (rc && (rc != -EEXIST || !quiet)) failed++; } - psi->close(psi); + if (psi->close) + psi->close(psi); out: mutex_unlock(&psi->read_mutex);