// SPDX-License-Identifier: GPL-1.0+ /* * zcore module to export memory content and register sets for creating system * dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same * dump format as s390 standalone dumps. * * For more information please refer to Documentation/s390/zfcpdump.rst * * Copyright IBM Corp. 2003, 2008 * Author(s): Michael Holzheu */ #define KMSG_COMPONENT "zdump" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "sclp.h" #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x) #define CHUNK_INFO_SIZE 34 /* 2 16-byte char, each followed by blank */ enum arch_id { ARCH_S390 = 0, ARCH_S390X = 1, }; struct ipib_info { unsigned long ipib; u32 checksum; } __attribute__((packed)); static struct debug_info *zcore_dbf; static int hsa_available; static struct dentry *zcore_dir; static struct dentry *zcore_memmap_file; static struct dentry *zcore_reipl_file; static struct dentry *zcore_hsa_file; static struct ipl_parameter_block *zcore_ipl_block; static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE); /* * Copy memory from HSA to user memory (not reentrant): * * @dest: User buffer where memory should be copied to * @src: Start address within HSA where data should be copied * @count: Size of buffer, which should be copied */ int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count) { unsigned long offset, bytes; if (!hsa_available) return -ENODATA; while (count) { if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) { TRACE("sclp_sdias_copy() failed\n"); return -EIO; } offset = src % PAGE_SIZE; bytes = min(PAGE_SIZE - offset, count); if (copy_to_user(dest, hsa_buf + offset, bytes)) return -EFAULT; src += bytes; dest += bytes; count -= bytes; } return 0; } /* * Copy memory from HSA to kernel memory (not reentrant): * * @dest: Kernel or user buffer where memory should be copied to * @src: Start address within HSA where data should be copied * @count: Size of buffer, which should be copied */ int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count) { unsigned long offset, bytes; if (!hsa_available) return -ENODATA; while (count) { if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) { TRACE("sclp_sdias_copy() failed\n"); return -EIO; } offset = src % PAGE_SIZE; bytes = min(PAGE_SIZE - offset, count); memcpy(dest, hsa_buf + offset, bytes); src += bytes; dest += bytes; count -= bytes; } return 0; } static int __init init_cpu_info(void) { struct save_area *sa; /* get info for boot cpu from lowcore, stored in the HSA */ sa = save_area_boot_cpu(); if (!sa) return -ENOMEM; if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) { TRACE("could not copy from HSA\n"); return -EIO; } save_area_add_regs(sa, hsa_buf); /* vx registers are saved in smp.c */ return 0; } /* * Release the HSA */ static void release_hsa(void) { diag308(DIAG308_REL_HSA, NULL); hsa_available = 0; } static ssize_t zcore_memmap_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) { return simple_read_from_buffer(buf, count, ppos, filp->private_data, memblock.memory.cnt * CHUNK_INFO_SIZE); } static int zcore_memmap_open(struct inode *inode, struct file *filp) { struct memblock_region *reg; char *buf; int i = 0; buf = kcalloc(memblock.memory.cnt, CHUNK_INFO_SIZE, GFP_KERNEL); if (!buf) { return -ENOMEM; } for_each_memblock(memory, reg) { sprintf(buf + (i++ * CHUNK_INFO_SIZE), "%016llx %016llx ", (unsigned long long) reg->base, (unsigned long long) reg->size); } filp->private_data = buf; return nonseekable_open(inode, filp); } static int zcore_memmap_release(struct inode *inode, struct file *filp) { kfree(filp->private_data); return 0; } static const struct file_operations zcore_memmap_fops = { .owner = THIS_MODULE, .read = zcore_memmap_read, .open = zcore_memmap_open, .release = zcore_memmap_release, .llseek = no_llseek, }; static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { if (zcore_ipl_block) { diag308(DIAG308_SET, zcore_ipl_block); diag308(DIAG308_LOAD_CLEAR, NULL); } return count; } static int zcore_reipl_open(struct inode *inode, struct file *filp) { return stream_open(inode, filp); } static int zcore_reipl_release(struct inode *inode, struct file *filp) { return 0; } static const struct file_operations zcore_reipl_fops = { .owner = THIS_MODULE, .write = zcore_reipl_write, .open = zcore_reipl_open, .release = zcore_reipl_release, .llseek = no_llseek, }; static ssize_t zcore_hsa_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) { static char str[18]; if (hsa_available) snprintf(str, sizeof(str), "%lx\n", sclp.hsa_size); else snprintf(str, sizeof(str), "0\n"); return simple_read_from_buffer(buf, count, ppos, str, strlen(str)); } static ssize_t zcore_hsa_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { char value; if (*ppos != 0) return -EPIPE; if (copy_from_user(&value, buf, 1)) return -EFAULT; if (value != '0') return -EINVAL; release_hsa(); return count; } static const struct file_operations zcore_hsa_fops = { .owner = THIS_MODULE, .write = zcore_hsa_write, .read = zcore_hsa_read, .open = nonseekable_open, .llseek = no_llseek, }; static int __init check_sdias(void) { if (!sclp.hsa_size) { TRACE("Could not determine HSA size\n"); return -ENODEV; } return 0; } /* * Provide IPL parameter information block from either HSA or memory * for future reipl */ static int __init zcore_reipl_init(void) { struct ipib_info ipib_info; int rc; rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info)); if (rc) return rc; if (ipib_info.ipib == 0) return 0; zcore_ipl_block = (void *) __get_free_page(GFP_KERNEL); if (!zcore_ipl_block) return -ENOMEM; if (ipib_info.ipib < sclp.hsa_size) rc = memcpy_hsa_kernel(zcore_ipl_block, ipib_info.ipib, PAGE_SIZE); else rc = memcpy_real(zcore_ipl_block, (void *) ipib_info.ipib, PAGE_SIZE); if (rc || (__force u32)csum_partial(zcore_ipl_block, zcore_ipl_block->hdr.len, 0) != ipib_info.checksum) { TRACE("Checksum does not match\n"); free_page((unsigned long) zcore_ipl_block); zcore_ipl_block = NULL; } return 0; } static int __init zcore_init(void) { unsigned char arch; int rc; if (ipl_info.type != IPL_TYPE_FCP_DUMP) return -ENODATA; if (OLDMEM_BASE) return -ENODATA; zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long)); debug_register_view(zcore_dbf, &debug_sprintf_view); debug_set_level(zcore_dbf, 6); TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno); TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn); TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun); rc = sclp_sdias_init(); if (rc) goto fail; rc = check_sdias(); if (rc) goto fail; hsa_available = 1; rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1); if (rc) goto fail; if (arch == ARCH_S390) { pr_alert("The 64-bit dump tool cannot be used for a " "32-bit system\n"); rc = -EINVAL; goto fail; } pr_alert("The dump process started for a 64-bit operating system\n"); rc = init_cpu_info(); if (rc) goto fail; rc = zcore_reipl_init(); if (rc) goto fail; zcore_dir = debugfs_create_dir("zcore" , NULL); if (!zcore_dir) { rc = -ENOMEM; goto fail; } zcore_memmap_file = debugfs_create_file("memmap", S_IRUSR, zcore_dir, NULL, &zcore_memmap_fops); if (!zcore_memmap_file) { rc = -ENOMEM; goto fail_dir; } zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir, NULL, &zcore_reipl_fops); if (!zcore_reipl_file) { rc = -ENOMEM; goto fail_memmap_file; } zcore_hsa_file = debugfs_create_file("hsa", S_IRUSR|S_IWUSR, zcore_dir, NULL, &zcore_hsa_fops); if (!zcore_hsa_file) { rc = -ENOMEM; goto fail_reipl_file; } return 0; fail_reipl_file: debugfs_remove(zcore_reipl_file); fail_memmap_file: debugfs_remove(zcore_memmap_file); fail_dir: debugfs_remove(zcore_dir); fail: diag308(DIAG308_REL_HSA, NULL); return rc; } subsys_initcall(zcore_init);