/* * RAM Oops/Panic logger * * Copyright (C) 2010 Marco Stornelli * * 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 #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)"); static struct ramoops_context { struct kmsg_dumper dump; void *virt_addr; phys_addr_t phys_addr; unsigned long size; unsigned long record_size; int dump_oops; int count; int max_count; } oops_cxt; static struct platform_device *dummy; static struct ramoops_platform_data *dummy_data; static void ramoops_do_dump(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason, const char *s1, unsigned long l1, const char *s2, unsigned long l2) { struct ramoops_context *cxt = container_of(dumper, struct ramoops_context, dump); unsigned long s1_start, s2_start; unsigned long l1_cpy, l2_cpy; int res, hdr_size; char *buf, *buf_orig; struct timeval timestamp; if (reason != KMSG_DUMP_OOPS && reason != KMSG_DUMP_PANIC && reason != KMSG_DUMP_KEXEC) return; /* Only dump oopses if dump_oops is set */ if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) return; buf = cxt->virt_addr + (cxt->count * cxt->record_size); buf_orig = buf; memset(buf, '\0', cxt->record_size); res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); buf += res; do_gettimeofday(×tamp); res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); buf += res; hdr_size = buf - buf_orig; l2_cpy = min(l2, cxt->record_size - hdr_size); l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy); s2_start = l2 - l2_cpy; s1_start = l1 - l1_cpy; memcpy(buf, s1 + s1_start, l1_cpy); memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy); cxt->count = (cxt->count + 1) % cxt->max_count; } 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; if (!pdata->mem_size || !pdata->record_size) { pr_err("The memory size and the record size must be " "non-zero\n"); goto fail3; } rounddown_pow_of_two(pdata->mem_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, minium is %lu\n", MIN_MEM_SIZE); goto fail3; } if (pdata->mem_size < pdata->record_size) { pr_err("The memory size must be larger than the " "records size\n"); goto fail3; } 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; /* * 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; if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) { pr_err("request mem region failed\n"); err = -EINVAL; goto fail3; } cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size); if (!cxt->virt_addr) { pr_err("ioremap failed\n"); goto fail2; } cxt->dump.dump = ramoops_do_dump; err = kmsg_dump_register(&cxt->dump); if (err) { pr_err("registering kmsg dumper failed\n"); goto fail1; } return 0; fail1: iounmap(cxt->virt_addr); fail2: release_mem_region(cxt->phys_addr, cxt->size); fail3: return err; } static int __exit ramoops_remove(struct platform_device *pdev) { struct ramoops_context *cxt = &oops_cxt; if (kmsg_dump_unregister(&cxt->dump) < 0) pr_warn("could not unregister kmsg_dumper\n"); iounmap(cxt->virt_addr); release_mem_region(cxt->phys_addr, cxt->size); return 0; } 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");