/* * 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 #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 ramoops_console_size = MIN_MEM_SIZE; module_param_named(console_size, ramoops_console_size, ulong, 0400); MODULE_PARM_DESC(console_size, "size of kernel console log"); static ulong ramoops_ftrace_size = MIN_MEM_SIZE; module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400); MODULE_PARM_DESC(ftrace_size, "size of ftrace log"); 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 int ramoops_ecc; module_param_named(ecc, ramoops_ecc, int, 0600); MODULE_PARM_DESC(ramoops_ecc, "if non-zero, the option enables ECC support and specifies " "ECC buffer size in bytes (1 is a special value, means 16 " "bytes ECC)"); struct ramoops_context { struct persistent_ram_zone **przs; struct persistent_ram_zone *cprz; struct persistent_ram_zone *fprz; phys_addr_t phys_addr; unsigned long size; size_t record_size; size_t console_size; size_t ftrace_size; int dump_oops; int ecc_size; unsigned int max_dump_cnt; unsigned int dump_write_cnt; unsigned int dump_read_cnt; unsigned int console_read_cnt; unsigned int ftrace_read_cnt; 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->dump_read_cnt = 0; cxt->console_read_cnt = 0; return 0; } static struct persistent_ram_zone * ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max, u64 *id, enum pstore_type_id *typep, enum pstore_type_id type, bool update) { struct persistent_ram_zone *prz; int i = (*c)++; if (i >= max) return NULL; prz = przs[i]; if (update) { /* Update old/shadowed buffer. */ persistent_ram_save_old(prz); if (!persistent_ram_old_size(prz)) return NULL; } *typep = type; *id = i; return prz; } static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, int *count, struct timespec *time, char **buf, struct pstore_info *psi) { ssize_t size; struct ramoops_context *cxt = psi->data; struct persistent_ram_zone *prz; prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, cxt->max_dump_cnt, id, type, PSTORE_TYPE_DMESG, 1); if (!prz) prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt, 1, id, type, PSTORE_TYPE_CONSOLE, 0); if (!prz) prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt, 1, id, type, PSTORE_TYPE_FTRACE, 0); if (!prz) return 0; /* TODO(kees): Bogus time for the moment. */ time->tv_sec = 0; time->tv_nsec = 0; size = persistent_ram_old_size(prz); *buf = kmemdup(persistent_ram_old(prz), size, GFP_KERNEL); if (*buf == NULL) return -ENOMEM; return size; } static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz) { char *hdr; struct timespec timestamp; size_t len; /* Report zeroed timestamp if called before timekeeping has resumed. */ if (__getnstimeofday(×tamp)) { timestamp.tv_sec = 0; timestamp.tv_nsec = 0; } hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n", (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000)); WARN_ON_ONCE(!hdr); len = hdr ? strlen(hdr) : 0; persistent_ram_write(prz, hdr, len); kfree(hdr); return len; } static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, enum kmsg_dump_reason reason, u64 *id, unsigned int part, const char *buf, size_t size, struct pstore_info *psi) { struct ramoops_context *cxt = psi->data; struct persistent_ram_zone *prz; size_t hlen; if (type == PSTORE_TYPE_CONSOLE) { if (!cxt->cprz) return -ENOMEM; persistent_ram_write(cxt->cprz, buf, size); return 0; } else if (type == PSTORE_TYPE_FTRACE) { if (!cxt->fprz) return -ENOMEM; persistent_ram_write(cxt->fprz, buf, size); return 0; } 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; if (!cxt->przs) return -ENOSPC; prz = cxt->przs[cxt->dump_write_cnt]; hlen = ramoops_write_kmsg_hdr(prz); if (size + hlen > prz->buffer_size) size = prz->buffer_size - hlen; persistent_ram_write(prz, buf, size); cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt; return 0; } static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count, struct timespec time, struct pstore_info *psi) { struct ramoops_context *cxt = psi->data; struct persistent_ram_zone *prz; switch (type) { case PSTORE_TYPE_DMESG: if (id >= cxt->max_dump_cnt) return -EINVAL; prz = cxt->przs[id]; break; case PSTORE_TYPE_CONSOLE: prz = cxt->cprz; break; case PSTORE_TYPE_FTRACE: prz = cxt->fprz; break; default: return -EINVAL; } persistent_ram_free_old(prz); persistent_ram_zap(prz); return 0; } static struct ramoops_context oops_cxt = { .pstore = { .owner = THIS_MODULE, .name = "ramoops", .open = ramoops_pstore_open, .read = ramoops_pstore_read, .write_buf = ramoops_pstore_write_buf, .erase = ramoops_pstore_erase, }, }; static void ramoops_free_przs(struct ramoops_context *cxt) { int i; if (!cxt->przs) return; for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++) persistent_ram_free(cxt->przs[i]); kfree(cxt->przs); } static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt, phys_addr_t *paddr, size_t dump_mem_sz) { int err = -ENOMEM; int i; if (!cxt->record_size) return 0; if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) { dev_err(dev, "no room for dumps\n"); return -ENOMEM; } cxt->max_dump_cnt = dump_mem_sz / cxt->record_size; if (!cxt->max_dump_cnt) return -ENOMEM; cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt, GFP_KERNEL); if (!cxt->przs) { dev_err(dev, "failed to initialize a prz array for dumps\n"); return -ENOMEM; } for (i = 0; i < cxt->max_dump_cnt; i++) { size_t sz = cxt->record_size; cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, cxt->ecc_size); if (IS_ERR(cxt->przs[i])) { err = PTR_ERR(cxt->przs[i]); dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", sz, (unsigned long long)*paddr, err); goto fail_prz; } *paddr += sz; } return 0; fail_prz: ramoops_free_przs(cxt); return err; } static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, struct persistent_ram_zone **prz, phys_addr_t *paddr, size_t sz, u32 sig) { if (!sz) return 0; if (*paddr + sz - cxt->phys_addr > cxt->size) { dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n", sz, (unsigned long long)*paddr, cxt->size, (unsigned long long)cxt->phys_addr); return -ENOMEM; } *prz = persistent_ram_new(*paddr, sz, sig, cxt->ecc_size); if (IS_ERR(*prz)) { int err = PTR_ERR(*prz); dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", sz, (unsigned long long)*paddr, err); return err; } persistent_ram_zap(*prz); *paddr += sz; return 0; } static int ramoops_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct ramoops_platform_data *pdata = pdev->dev.platform_data; struct ramoops_context *cxt = &oops_cxt; size_t dump_mem_sz; phys_addr_t paddr; int err = -EINVAL; /* Only a single ramoops area allowed at a time, so fail extra * probes. */ if (cxt->max_dump_cnt) goto fail_out; if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size && !pdata->ftrace_size)) { pr_err("The memory size and the record/console size must be " "non-zero\n"); goto fail_out; } if (!is_power_of_2(pdata->mem_size)) pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); if (!is_power_of_2(pdata->record_size)) pdata->record_size = rounddown_pow_of_two(pdata->record_size); if (!is_power_of_2(pdata->console_size)) pdata->console_size = rounddown_pow_of_two(pdata->console_size); if (!is_power_of_2(pdata->ftrace_size)) pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); cxt->dump_read_cnt = 0; cxt->size = pdata->mem_size; cxt->phys_addr = pdata->mem_address; cxt->record_size = pdata->record_size; cxt->console_size = pdata->console_size; cxt->ftrace_size = pdata->ftrace_size; cxt->dump_oops = pdata->dump_oops; cxt->ecc_size = pdata->ecc_size; paddr = cxt->phys_addr; dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size; err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz); if (err) goto fail_out; err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr, cxt->console_size, 0); if (err) goto fail_init_cprz; err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size, LINUX_VERSION_CODE); if (err) goto fail_init_fprz; if (!cxt->przs && !cxt->cprz && !cxt->fprz) { pr_err("memory size too small, minimum is %zu\n", cxt->console_size + cxt->record_size + cxt->ftrace_size); goto fail_cnt; } cxt->pstore.data = cxt; /* * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we * have to handle dumps, we must have at least record_size buffer. And * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be * ZERO_SIZE_PTR). */ if (cxt->console_size) cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */ cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize); 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; } err = pstore_register(&cxt->pstore); if (err) { pr_err("registering with pstore failed\n"); goto fail_buf; } /* * 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, ecc: %d\n", cxt->size, (unsigned long long)cxt->phys_addr, cxt->ecc_size); return 0; fail_buf: kfree(cxt->pstore.buf); fail_clear: cxt->pstore.bufsize = 0; cxt->max_dump_cnt = 0; fail_cnt: kfree(cxt->fprz); fail_init_fprz: kfree(cxt->cprz); fail_init_cprz: ramoops_free_przs(cxt); 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_dump_cnt = 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 = { .probe = ramoops_probe, .remove = __exit_p(ramoops_remove), .driver = { .name = "ramoops", .owner = THIS_MODULE, }, }; static void ramoops_register_dummy(void) { if (!mem_size) return; pr_info("using module parameters\n"); dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL); if (!dummy_data) { pr_info("could not allocate pdata\n"); return; } dummy_data->mem_size = mem_size; dummy_data->mem_address = mem_address; dummy_data->record_size = record_size; dummy_data->console_size = ramoops_console_size; dummy_data->ftrace_size = ramoops_ftrace_size; dummy_data->dump_oops = dump_oops; /* * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC * (using 1 byte for ECC isn't much of use anyway). */ dummy_data->ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc; dummy = platform_device_register_data(NULL, "ramoops", -1, dummy_data, sizeof(struct ramoops_platform_data)); if (IS_ERR(dummy)) { pr_info("could not create platform device: %ld\n", PTR_ERR(dummy)); } } static int __init ramoops_init(void) { ramoops_register_dummy(); return platform_driver_register(&ramoops_driver); } postcore_initcall(ramoops_init); static void __exit ramoops_exit(void) { platform_driver_unregister(&ramoops_driver); platform_device_unregister(dummy); kfree(dummy_data); } module_exit(ramoops_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marco Stornelli "); MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");