From 1894a253db97059bc299b834b76f665bc6586b1d Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Wed, 16 May 2012 05:43:08 -0700 Subject: ramoops: Move to fs/pstore/ram.c Since ramoops was converted to pstore, it has nothing to do with character devices nowadays. Instead, today it is just a RAM backend for pstore. The patch just moves things around. There are a few changes were needed because of the move: 1. Kconfig and Makefiles fixups, of course. 2. In pstore/ram.c we have to play a bit with MODULE_PARAM_PREFIX, this is needed to keep user experience the same as with ramoops driver (i.e. so that ramoops.foo kernel command line arguments would still work). Signed-off-by: Anton Vorontsov Acked-by: Marco Stornelli Acked-by: Kees Cook Signed-off-by: Greg Kroah-Hartman --- fs/pstore/Kconfig | 14 +++ fs/pstore/Makefile | 3 + fs/pstore/ram.c | 362 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 379 insertions(+) create mode 100644 fs/pstore/ram.c (limited to 'fs/pstore') diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 8007ae7c0d8..b75ee51b271 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -11,3 +11,17 @@ config PSTORE (e.g. ACPI_APEI on X86) which will select this for you. If you don't have a platform persistent store driver, say N. + +config PSTORE_RAM + tristate "Log panic/oops to a RAM buffer" + depends on HAS_IOMEM + depends on PSTORE + default n + help + This enables panic and oops messages to be logged to a circular + buffer in RAM where it can be read back at some later point. + + Note that for historical reasons, the module will be named + "ramoops.ko". + + For more information, see Documentation/ramoops.txt. diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile index 760f4bce7d1..2ab3d0d55ef 100644 --- a/fs/pstore/Makefile +++ b/fs/pstore/Makefile @@ -5,3 +5,6 @@ obj-y += pstore.o pstore-objs += inode.o platform.o + +ramoops-objs += ram.o +obj-$(CONFIG_PSTORE_RAM) += ramoops.o diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c new file mode 100644 index 00000000000..e443c9c6914 --- /dev/null +++ b/fs/pstore/ram.c @@ -0,0 +1,362 @@ +/* + * RAM Oops/Panic logger + * + * Copyright (C) 2010 Marco Stornelli + * Copyright (C) 2011 Kees Cook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define RAMOOPS_KERNMSG_HDR "====" +#define MIN_MEM_SIZE 4096UL + +static ulong record_size = MIN_MEM_SIZE; +module_param(record_size, ulong, 0400); +MODULE_PARM_DESC(record_size, + "size of each dump done on oops/panic"); + +static ulong mem_address; +module_param(mem_address, ulong, 0400); +MODULE_PARM_DESC(mem_address, + "start of reserved RAM used to store oops/panic logs"); + +static ulong mem_size; +module_param(mem_size, ulong, 0400); +MODULE_PARM_DESC(mem_size, + "size of reserved RAM used to store oops/panic logs"); + +static int dump_oops = 1; +module_param(dump_oops, int, 0600); +MODULE_PARM_DESC(dump_oops, + "set to 1 to dump oopses, 0 to only dump panics (default 1)"); + +struct ramoops_context { + void *virt_addr; + phys_addr_t phys_addr; + unsigned long size; + size_t record_size; + int dump_oops; + unsigned int count; + unsigned int max_count; + unsigned int read_count; + struct pstore_info pstore; +}; + +static struct platform_device *dummy; +static struct ramoops_platform_data *dummy_data; + +static int ramoops_pstore_open(struct pstore_info *psi) +{ + struct ramoops_context *cxt = psi->data; + + cxt->read_count = 0; + return 0; +} + +static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, + struct timespec *time, + char **buf, + struct pstore_info *psi) +{ + ssize_t size; + char *rambuf; + struct ramoops_context *cxt = psi->data; + + if (cxt->read_count >= cxt->max_count) + return -EINVAL; + *id = cxt->read_count++; + /* Only supports dmesg output so far. */ + *type = PSTORE_TYPE_DMESG; + /* TODO(kees): Bogus time for the moment. */ + time->tv_sec = 0; + time->tv_nsec = 0; + + rambuf = cxt->virt_addr + (*id * cxt->record_size); + size = strnlen(rambuf, cxt->record_size); + *buf = kmalloc(size, GFP_KERNEL); + if (*buf == NULL) + return -ENOMEM; + memcpy(*buf, rambuf, size); + + return size; +} + +static int ramoops_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 *buf; + size_t res; + struct timeval timestamp; + struct ramoops_context *cxt = psi->data; + size_t available = cxt->record_size; + + /* Currently ramoops is designed to only store dmesg dumps. */ + if (type != PSTORE_TYPE_DMESG) + return -EINVAL; + + /* Out of the various dmesg dump types, ramoops is currently designed + * to only store crash logs, rather than storing general kernel logs. + */ + if (reason != KMSG_DUMP_OOPS && + reason != KMSG_DUMP_PANIC) + return -EINVAL; + + /* Skip Oopes when configured to do so. */ + if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) + return -EINVAL; + + /* Explicitly only take the first part of any new crash. + * If our buffer is larger than kmsg_bytes, this can never happen, + * and if our buffer is smaller than kmsg_bytes, we don't want the + * report split across multiple records. + */ + if (part != 1) + return -ENOSPC; + + buf = cxt->virt_addr + (cxt->count * cxt->record_size); + + res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); + buf += res; + available -= res; + + do_gettimeofday(×tamp); + res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); + buf += res; + available -= res; + + if (size > available) + size = available; + + memcpy(buf, cxt->pstore.buf, size); + memset(buf + size, '\0', available - size); + + cxt->count = (cxt->count + 1) % cxt->max_count; + + return 0; +} + +static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, + struct pstore_info *psi) +{ + char *buf; + struct ramoops_context *cxt = psi->data; + + if (id >= cxt->max_count) + return -EINVAL; + + buf = cxt->virt_addr + (id * cxt->record_size); + memset(buf, '\0', cxt->record_size); + + return 0; +} + +static struct ramoops_context oops_cxt = { + .pstore = { + .owner = THIS_MODULE, + .name = "ramoops", + .open = ramoops_pstore_open, + .read = ramoops_pstore_read, + .write = ramoops_pstore_write, + .erase = ramoops_pstore_erase, + }, +}; + +static int __init ramoops_probe(struct platform_device *pdev) +{ + struct ramoops_platform_data *pdata = pdev->dev.platform_data; + struct ramoops_context *cxt = &oops_cxt; + int err = -EINVAL; + + /* Only a single ramoops area allowed at a time, so fail extra + * probes. + */ + if (cxt->max_count) + goto fail_out; + + if (!pdata->mem_size || !pdata->record_size) { + pr_err("The memory size and the record size must be " + "non-zero\n"); + goto fail_out; + } + + pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); + pdata->record_size = rounddown_pow_of_two(pdata->record_size); + + /* Check for the minimum memory size */ + if (pdata->mem_size < MIN_MEM_SIZE && + pdata->record_size < MIN_MEM_SIZE) { + pr_err("memory size too small, minimum is %lu\n", + MIN_MEM_SIZE); + goto fail_out; + } + + if (pdata->mem_size < pdata->record_size) { + pr_err("The memory size must be larger than the " + "records size\n"); + goto fail_out; + } + + cxt->max_count = pdata->mem_size / pdata->record_size; + cxt->count = 0; + cxt->size = pdata->mem_size; + cxt->phys_addr = pdata->mem_address; + cxt->record_size = pdata->record_size; + cxt->dump_oops = pdata->dump_oops; + + cxt->pstore.data = cxt; + cxt->pstore.bufsize = cxt->record_size; + cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL); + spin_lock_init(&cxt->pstore.buf_lock); + if (!cxt->pstore.buf) { + pr_err("cannot allocate pstore buffer\n"); + goto fail_clear; + } + + if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) { + pr_err("request mem region (0x%lx@0x%llx) failed\n", + cxt->size, (unsigned long long)cxt->phys_addr); + err = -EINVAL; + goto fail_buf; + } + + cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size); + if (!cxt->virt_addr) { + pr_err("ioremap failed\n"); + goto fail_mem_region; + } + + err = pstore_register(&cxt->pstore); + if (err) { + pr_err("registering with pstore failed\n"); + goto fail_iounmap; + } + + /* + * Update the module parameter variables as well so they are visible + * through /sys/module/ramoops/parameters/ + */ + mem_size = pdata->mem_size; + mem_address = pdata->mem_address; + record_size = pdata->record_size; + dump_oops = pdata->dump_oops; + + pr_info("attached 0x%lx@0x%llx (%ux0x%zx)\n", + cxt->size, (unsigned long long)cxt->phys_addr, + cxt->max_count, cxt->record_size); + + return 0; + +fail_iounmap: + iounmap(cxt->virt_addr); +fail_mem_region: + release_mem_region(cxt->phys_addr, cxt->size); +fail_buf: + kfree(cxt->pstore.buf); +fail_clear: + cxt->pstore.bufsize = 0; + cxt->max_count = 0; +fail_out: + return err; +} + +static int __exit ramoops_remove(struct platform_device *pdev) +{ +#if 0 + /* TODO(kees): We cannot unload ramoops since pstore doesn't support + * unregistering yet. + */ + struct ramoops_context *cxt = &oops_cxt; + + iounmap(cxt->virt_addr); + release_mem_region(cxt->phys_addr, cxt->size); + cxt->max_count = 0; + + /* TODO(kees): When pstore supports unregistering, call it here. */ + kfree(cxt->pstore.buf); + cxt->pstore.bufsize = 0; + + return 0; +#endif + return -EBUSY; +} + +static struct platform_driver ramoops_driver = { + .remove = __exit_p(ramoops_remove), + .driver = { + .name = "ramoops", + .owner = THIS_MODULE, + }, +}; + +static int __init ramoops_init(void) +{ + int ret; + ret = platform_driver_probe(&ramoops_driver, ramoops_probe); + if (ret == -ENODEV) { + /* + * If we didn't find a platform device, we use module parameters + * building platform data on the fly. + */ + pr_info("platform device not found, using module parameters\n"); + dummy_data = kzalloc(sizeof(struct ramoops_platform_data), + GFP_KERNEL); + if (!dummy_data) + return -ENOMEM; + dummy_data->mem_size = mem_size; + dummy_data->mem_address = mem_address; + dummy_data->record_size = record_size; + dummy_data->dump_oops = dump_oops; + dummy = platform_create_bundle(&ramoops_driver, ramoops_probe, + NULL, 0, dummy_data, + sizeof(struct ramoops_platform_data)); + + if (IS_ERR(dummy)) + ret = PTR_ERR(dummy); + else + ret = 0; + } + + return ret; +} + +static void __exit ramoops_exit(void) +{ + platform_driver_unregister(&ramoops_driver); + kfree(dummy_data); +} + +module_init(ramoops_init); +module_exit(ramoops_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Marco Stornelli "); +MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); -- cgit v1.2.3