From c950fd6f201aea649932898206a850f0a7f25603 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 28 Jul 2016 00:08:25 +0900 Subject: pstore: Split pstore fragile flags This patch adds new PSTORE_FLAGS for each pstore type so that they can be enabled separately. This is a preparation for ongoing virtio-pstore work to support those types flexibly. The PSTORE_FLAGS_FRAGILE is changed to PSTORE_FLAGS_DMESG to preserve the original behavior. Cc: Anton Vorontsov Cc: Colin Cross Cc: Kees Cook Cc: Tony Luck Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Matt Fleming Cc: linux-acpi@vger.kernel.org Cc: linux-efi@vger.kernel.org Signed-off-by: Namhyung Kim [kees: retained "FRAGILE" for now to make merges easier] Signed-off-by: Kees Cook --- include/linux/pstore.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 899e95e84400..f5806b2a6f7a 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -74,7 +74,13 @@ struct pstore_info { void *data; }; -#define PSTORE_FLAGS_FRAGILE 1 +#define PSTORE_FLAGS_DMESG (1 << 0) +#define PSTORE_FLAGS_FRAGILE PSTORE_FLAGS_DMESG +#define PSTORE_FLAGS_CONSOLE (1 << 1) +#define PSTORE_FLAGS_FTRACE (1 << 2) +#define PSTORE_FLAGS_PMSG (1 << 3) + +#define PSTORE_FLAGS_ALL ((1 << 4) - 1) extern int pstore_register(struct pstore_info *); extern void pstore_unregister(struct pstore_info *); -- cgit v1.2.3 From 79d955af711a6e20207783590a2cfddbd649568b Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 28 Jul 2016 00:08:26 +0900 Subject: pstore/ram: Set pstore flags dynamically The ramoops can be configured to enable each pstore type by setting their size. In that case, it'd be better not to register disabled types in the first place. Cc: Anton Vorontsov Cc: Colin Cross Cc: Kees Cook Cc: Tony Luck Signed-off-by: Namhyung Kim Signed-off-by: Kees Cook --- fs/pstore/ram.c | 8 +++++++- include/linux/pstore.h | 2 -- 2 files changed, 7 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index c2ebf5084977..08597c524439 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -623,7 +623,13 @@ static int ramoops_probe(struct platform_device *pdev) goto fail_clear; } - cxt->pstore.flags = PSTORE_FLAGS_ALL; + cxt->pstore.flags = PSTORE_FLAGS_DMESG; + if (cxt->console_size) + cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; + if (cxt->ftrace_size) + cxt->pstore.flags |= PSTORE_FLAGS_FTRACE; + if (cxt->pmsg_size) + cxt->pstore.flags |= PSTORE_FLAGS_PMSG; err = pstore_register(&cxt->pstore); if (err) { diff --git a/include/linux/pstore.h b/include/linux/pstore.h index f5806b2a6f7a..50d475228d97 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -80,8 +80,6 @@ struct pstore_info { #define PSTORE_FLAGS_FTRACE (1 << 2) #define PSTORE_FLAGS_PMSG (1 << 3) -#define PSTORE_FLAGS_ALL ((1 << 4) - 1) - extern int pstore_register(struct pstore_info *); extern void pstore_unregister(struct pstore_info *); extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason); -- cgit v1.2.3 From 5bf6d1b92715f224ef6e1c3abca5dd63eeb4915d Mon Sep 17 00:00:00 2001 From: Mark Salyzyn Date: Thu, 1 Sep 2016 08:13:46 -0700 Subject: pstore/pmsg: drop bounce buffer Removing a bounce buffer copy operation in the pmsg driver path is always better. We also gain in overall performance by not requesting a vmalloc on every write as this can cause precious RT tasks, such as user facing media operation, to stall while memory is being reclaimed. Added a write_buf_user to the pstore functions, a backup platform write_buf_user that uses the small buffer that is part of the instance, and implemented a ramoops write_buf_user that only supports PSTORE_TYPE_PMSG. Signed-off-by: Mark Salyzyn Signed-off-by: Kees Cook --- fs/pstore/platform.c | 36 +++++++++++++++++++++++++++++++++++ fs/pstore/pmsg.c | 35 ++++++---------------------------- fs/pstore/ram.c | 19 +++++++++++++++++++ fs/pstore/ram_core.c | 47 ++++++++++++++++++++++++++++++++++++++++++++-- include/linux/pstore.h | 11 ++++++++--- include/linux/pstore_ram.h | 7 +++++-- 6 files changed, 119 insertions(+), 36 deletions(-) (limited to 'include') diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 76dd604a0f2c..14984d902a99 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -623,6 +623,40 @@ static int pstore_write_compat(enum pstore_type_id type, size, psi); } +static int pstore_write_buf_user_compat(enum pstore_type_id type, + enum kmsg_dump_reason reason, + u64 *id, unsigned int part, + const char __user *buf, + bool compressed, size_t size, + struct pstore_info *psi) +{ + unsigned long flags = 0; + size_t i, bufsize = size; + long ret = 0; + + if (unlikely(!access_ok(VERIFY_READ, buf, size))) + return -EFAULT; + if (bufsize > psinfo->bufsize) + bufsize = psinfo->bufsize; + spin_lock_irqsave(&psinfo->buf_lock, flags); + for (i = 0; i < size; ) { + size_t c = min(size - i, bufsize); + + ret = __copy_from_user(psinfo->buf, buf + i, c); + if (unlikely(ret != 0)) { + ret = -EFAULT; + break; + } + ret = psi->write_buf(type, reason, id, part, psinfo->buf, + compressed, c, psi); + if (unlikely(ret < 0)) + break; + i += c; + } + spin_unlock_irqrestore(&psinfo->buf_lock, flags); + return unlikely(ret < 0) ? ret : size; +} + /* * platform specific persistent storage driver registers with * us here. If pstore is already mounted, call the platform @@ -645,6 +679,8 @@ int pstore_register(struct pstore_info *psi) if (!psi->write) psi->write = pstore_write_compat; + if (!psi->write_buf_user) + psi->write_buf_user = pstore_write_buf_user_compat; psinfo = psi; mutex_init(&psinfo->read_mutex); spin_unlock(&pstore_lock); diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c index 7de20cd3797f..78f6176c020f 100644 --- a/fs/pstore/pmsg.c +++ b/fs/pstore/pmsg.c @@ -19,48 +19,25 @@ #include "internal.h" static DEFINE_MUTEX(pmsg_lock); -#define PMSG_MAX_BOUNCE_BUFFER_SIZE (2*PAGE_SIZE) static ssize_t write_pmsg(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - size_t i, buffer_size; - char *buffer; + u64 id; + int ret; if (!count) return 0; + /* check outside lock, page in any data. write_buf_user also checks */ if (!access_ok(VERIFY_READ, buf, count)) return -EFAULT; - buffer_size = count; - if (buffer_size > PMSG_MAX_BOUNCE_BUFFER_SIZE) - buffer_size = PMSG_MAX_BOUNCE_BUFFER_SIZE; - buffer = vmalloc(buffer_size); - if (!buffer) - return -ENOMEM; - mutex_lock(&pmsg_lock); - for (i = 0; i < count; ) { - size_t c = min(count - i, buffer_size); - u64 id; - long ret; - - ret = __copy_from_user(buffer, buf + i, c); - if (unlikely(ret != 0)) { - mutex_unlock(&pmsg_lock); - vfree(buffer); - return -EFAULT; - } - psinfo->write_buf(PSTORE_TYPE_PMSG, 0, &id, 0, buffer, 0, c, - psinfo); - - i += c; - } - + ret = psinfo->write_buf_user(PSTORE_TYPE_PMSG, 0, &id, 0, buf, 0, count, + psinfo); mutex_unlock(&pmsg_lock); - vfree(buffer); - return count; + return ret ? ret : count; } static const struct file_operations pmsg_fops = { diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 08597c524439..f3e3cf00d8b9 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -331,6 +331,24 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, return 0; } +static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type, + enum kmsg_dump_reason reason, + u64 *id, unsigned int part, + const char __user *buf, + bool compressed, size_t size, + struct pstore_info *psi) +{ + if (type == PSTORE_TYPE_PMSG) { + struct ramoops_context *cxt = psi->data; + + if (!cxt->mprz) + return -ENOMEM; + return persistent_ram_write_user(cxt->mprz, buf, size); + } + + return -EINVAL; +} + static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count, struct timespec time, struct pstore_info *psi) { @@ -369,6 +387,7 @@ static struct ramoops_context oops_cxt = { .open = ramoops_pstore_open, .read = ramoops_pstore_read, .write_buf = ramoops_pstore_write_buf, + .write_buf_user = ramoops_pstore_write_buf_user, .erase = ramoops_pstore_erase, }, }; diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 9cc6efe0b785..9486c4873c69 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -17,15 +17,16 @@ #include #include #include -#include #include #include +#include #include #include +#include #include #include +#include #include -#include #include struct persistent_ram_buffer { @@ -267,6 +268,16 @@ static void notrace persistent_ram_update(struct persistent_ram_zone *prz, persistent_ram_update_ecc(prz, start, count); } +static int notrace persistent_ram_update_user(struct persistent_ram_zone *prz, + const void __user *s, unsigned int start, unsigned int count) +{ + struct persistent_ram_buffer *buffer = prz->buffer; + int ret = unlikely(__copy_from_user(buffer->data + start, s, count)) ? + -EFAULT : 0; + persistent_ram_update_ecc(prz, start, count); + return ret; +} + void persistent_ram_save_old(struct persistent_ram_zone *prz) { struct persistent_ram_buffer *buffer = prz->buffer; @@ -320,6 +331,38 @@ int notrace persistent_ram_write(struct persistent_ram_zone *prz, return count; } +int notrace persistent_ram_write_user(struct persistent_ram_zone *prz, + const void __user *s, unsigned int count) +{ + int rem, ret = 0, c = count; + size_t start; + + if (unlikely(!access_ok(VERIFY_READ, s, count))) + return -EFAULT; + if (unlikely(c > prz->buffer_size)) { + s += c - prz->buffer_size; + c = prz->buffer_size; + } + + buffer_size_add(prz, c); + + start = buffer_start_add(prz, c); + + rem = prz->buffer_size - start; + if (unlikely(rem < c)) { + ret = persistent_ram_update_user(prz, s, start, rem); + s += rem; + c -= rem; + start = 0; + } + if (likely(!ret)) + ret = persistent_ram_update_user(prz, s, start, c); + + persistent_ram_update_header_ecc(prz); + + return unlikely(ret) ? ret : count; +} + size_t persistent_ram_old_size(struct persistent_ram_zone *prz) { return prz->old_log_size; diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 50d475228d97..92013cc9cc8c 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -22,12 +22,13 @@ #ifndef _LINUX_PSTORE_H #define _LINUX_PSTORE_H -#include +#include +#include #include #include -#include #include -#include +#include +#include /* types */ enum pstore_type_id { @@ -68,6 +69,10 @@ struct pstore_info { enum kmsg_dump_reason reason, u64 *id, unsigned int part, const char *buf, bool compressed, size_t size, struct pstore_info *psi); + int (*write_buf_user)(enum pstore_type_id type, + enum kmsg_dump_reason reason, u64 *id, + unsigned int part, const char __user *buf, + bool compressed, size_t size, struct pstore_info *psi); int (*erase)(enum pstore_type_id type, u64 id, int count, struct timespec time, struct pstore_info *psi); diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index 4660aaa3195e..c668c861c96c 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -17,11 +17,12 @@ #ifndef __LINUX_PSTORE_RAM_H__ #define __LINUX_PSTORE_RAM_H__ +#include #include +#include #include #include #include -#include struct persistent_ram_buffer; struct rs_control; @@ -59,7 +60,9 @@ void persistent_ram_free(struct persistent_ram_zone *prz); void persistent_ram_zap(struct persistent_ram_zone *prz); int persistent_ram_write(struct persistent_ram_zone *prz, const void *s, - unsigned int count); + unsigned int count); +int persistent_ram_write_user(struct persistent_ram_zone *prz, + const void __user *s, unsigned int count); void persistent_ram_save_old(struct persistent_ram_zone *prz); size_t persistent_ram_old_size(struct persistent_ram_zone *prz); -- cgit v1.2.3