From ffa52d02c50ea31420dc70869c0b6b439e7cb5ef Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 28 Oct 2015 09:47:58 +0100 Subject: [PATCH] s390/zcore: remove /sys/kernel/debug/zcore/mem New versions of the SCSI dumper use the /dev/vmcore interface instead of zcore mem. Remove the outdated interface. Acked-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- Documentation/s390/zfcpdump.txt | 22 +- arch/s390/include/asm/lowcore.h | 1 - drivers/s390/char/Makefile | 4 +- drivers/s390/char/zcore.c | 394 +------------------------------- 4 files changed, 18 insertions(+), 403 deletions(-) diff --git a/Documentation/s390/zfcpdump.txt b/Documentation/s390/zfcpdump.txt index dc929be96016..b064aa59714d 100644 --- a/Documentation/s390/zfcpdump.txt +++ b/Documentation/s390/zfcpdump.txt @@ -15,19 +15,15 @@ the s390-tools package) to make the device bootable. The operator of a Linux system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump resides on. -The kernel part of zfcpdump is implemented as a debugfs file under "zcore/mem", -which exports memory and registers of the crashed Linux in an s390 -standalone dump format. It can be used in the same way as e.g. /dev/mem. The -dump format defines a 4K header followed by plain uncompressed memory. The -register sets are stored in the prefix pages of the respective CPUs. To build a -dump enabled kernel with the zcore driver, the kernel config option -CONFIG_CRASH_DUMP has to be set. When reading from "zcore/mem", the part of -memory, which has been saved by hardware is read by the driver via the SCLP -hardware interface. The second part is just copied from the non overwritten real -memory. - -Since kernel version 3.12 also the /proc/vmcore file can also be used to access -the dump. +The user space dump tool accesses the memory of the crashed system by means +of the /proc/vmcore interface. This interface exports the crashed system's +memory and registers in ELF core dump format. To access the memory which has +been saved by the hardware SCLP requests will be created at the time the data +is needed by /proc/vmcore. The tail part of the crashed systems memory which +has not been stashed by hardware can just be copied from real memory. + +To build a dump enabled kernel the kernel config option CONFIG_CRASH_DUMP +has to be set. To get a valid zfcpdump kernel configuration use "make zfcpdump_defconfig". diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h index bc618067e725..afe1cfebf1a4 100644 --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -35,7 +35,6 @@ struct save_area { struct save_area_ext { struct save_area sa; __vector128 vx_regs[32]; - u64 vx_sa_addr; }; struct _lowcore { diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile index 6fa9364d1c07..8a2632ba88dc 100644 --- a/drivers/s390/char/Makefile +++ b/drivers/s390/char/Makefile @@ -30,9 +30,7 @@ obj-$(CONFIG_S390_TAPE_3590) += tape_3590.o obj-$(CONFIG_MONREADER) += monreader.o obj-$(CONFIG_MONWRITER) += monwriter.o obj-$(CONFIG_S390_VMUR) += vmur.o - -zcore_mod-objs := sclp_sdias.o zcore.o -obj-$(CONFIG_CRASH_DUMP) += zcore_mod.o +obj-$(CONFIG_CRASH_DUMP) += sclp_sdias.o zcore.o hmcdrv-objs := hmcdrv_mod.o hmcdrv_dev.o hmcdrv_ftp.o hmcdrv_cache.o diag_ftp.o sclp_ftp.o obj-$(CONFIG_HMC_DRV) += hmcdrv.o diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c index e0c87a83eb34..3ad3d538e432 100644 --- a/drivers/s390/char/zcore.c +++ b/drivers/s390/char/zcore.c @@ -43,27 +43,14 @@ enum arch_id { ARCH_S390X = 1, }; -/* dump system info */ - -struct sys_info { - enum arch_id arch; - unsigned long sa_base; - u32 sa_size; - int cpu_map[NR_CPUS]; - unsigned long mem_size; - struct save_area lc_mask; -}; - struct ipib_info { unsigned long ipib; u32 checksum; } __attribute__((packed)); -static struct sys_info sys_info; static struct debug_info *zcore_dbf; static int hsa_available; static struct dentry *zcore_dir; -static struct dentry *zcore_file; static struct dentry *zcore_memmap_file; static struct dentry *zcore_reipl_file; static struct dentry *zcore_hsa_file; @@ -149,171 +136,22 @@ static int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count) return memcpy_hsa(dest, src, count, TO_KERNEL); } -static int __init init_cpu_info(enum arch_id arch) +static int __init init_cpu_info(void) { struct save_area_ext *sa_ext; - struct _lowcore *lc; - void *ptr; - int i; /* get info for boot cpu from lowcore, stored in the HSA */ sa_ext = dump_save_areas.areas[0]; if (!sa_ext) return -ENOMEM; - if (memcpy_hsa_kernel(&sa_ext->sa, sys_info.sa_base, - sys_info.sa_size) < 0) { + if (memcpy_hsa_kernel(&sa_ext->sa, SAVE_AREA_BASE, + sizeof(struct save_area)) < 0) { TRACE("could not copy from HSA\n"); return -EIO; } - if (!MACHINE_HAS_VX) - return 0; - - save_vx_regs_safe(sa_ext->vx_regs); - /* Get address of the vector register save area for each CPU */ - for (i = 0; i < dump_save_areas.count; i++) { - sa_ext = dump_save_areas.areas[i]; - lc = (struct _lowcore *)(unsigned long) sa_ext->sa.pref_reg; - ptr = &lc->vector_save_area_addr; - copy_from_oldmem(&sa_ext->vx_sa_addr, ptr, - sizeof(sa_ext->vx_sa_addr)); - } - return 0; -} - -static DEFINE_MUTEX(zcore_mutex); - -#define DUMP_VERSION 0x5 -#define DUMP_MAGIC 0xa8190173618f23fdULL -#define DUMP_ARCH_S390X 2 -#define DUMP_ARCH_S390 1 -#define HEADER_SIZE 4096 - -/* dump header dumped according to s390 crash dump format */ - -struct zcore_header { - u64 magic; - u32 version; - u32 header_size; - u32 dump_level; - u32 page_size; - u64 mem_size; - u64 mem_start; - u64 mem_end; - u32 num_pages; - u32 pad1; - u64 tod; - struct cpuid cpu_id; - u32 arch_id; - u32 volnr; - u32 build_arch; - u64 rmem_size; - u8 mvdump; - u16 cpu_cnt; - u16 real_cpu_cnt; - u8 end_pad1[0x200-0x061]; - u64 mvdump_sign; - u64 mvdump_zipl_time; - u8 end_pad2[0x800-0x210]; - u32 lc_vec[512]; -} __attribute__((packed,__aligned__(16))); - -static struct zcore_header zcore_header = { - .magic = DUMP_MAGIC, - .version = DUMP_VERSION, - .header_size = 4096, - .dump_level = 0, - .page_size = PAGE_SIZE, - .mem_start = 0, - .build_arch = DUMP_ARCH_S390X, -}; - -/* - * Copy lowcore info to buffer. Use map in order to copy only register parts. - * - * @buf: User buffer - * @sa: Pointer to save area - * @sa_off: Offset in save area to copy - * @len: Number of bytes to copy - */ -static int copy_lc(void __user *buf, void *sa, int sa_off, int len) -{ - int i; - char *lc_mask = (char*)&sys_info.lc_mask; - - for (i = 0; i < len; i++) { - if (!lc_mask[i + sa_off]) - continue; - if (copy_to_user(buf + i, sa + sa_off + i, 1)) - return -EFAULT; - } - return 0; -} - -/* - * Copy lowcores info to memory, if necessary - * - * @buf: User buffer - * @addr: Start address of buffer in dump memory - * @count: Size of buffer - */ -static int zcore_add_lc(char __user *buf, unsigned long start, size_t count) -{ - struct save_area_ext *sa_ext; - struct save_area *sa; - unsigned long end; - int i; - - if (count == 0) - return 0; - - end = start + count; - for (i = 0; i < dump_save_areas.count; i++) { - unsigned long cp_start, cp_end; /* copy range */ - unsigned long sa_start, sa_end; /* save area range */ - unsigned long sa_off, len, buf_off; - - sa_ext = dump_save_areas.areas[i]; - sa = &sa_ext->sa; - - /* Copy the 512 bytes lowcore save area 0x1200 - 0x1400 */ - sa_start = sa->pref_reg + sys_info.sa_base; - sa_end = sa_start + sys_info.sa_size; - - if (end >= sa_start && start < sa_end) { - cp_start = max(start, sa_start); - cp_end = min(end, sa_end); - buf_off = cp_start - start; - sa_off = cp_start - sa_start; - len = cp_end - cp_start; - - TRACE("copy_lc: %lx-%lx\n", cp_start, cp_end); - if (copy_lc(buf + buf_off, sa, sa_off, len)) - return -EFAULT; - } - - if (!MACHINE_HAS_VX) - continue; - - /* Copy the 512 bytes vector save area */ - sa_start = sa_ext->vx_sa_addr & -1024UL; - sa_end = sa_start + 512; - - if (end >= sa_start && start < sa_end) { - cp_start = max(start, sa_start); - cp_end = min(end, sa_end); - - buf_off = cp_start - start; - sa_off = cp_start - sa_start; - len = cp_end - cp_start; - - TRACE("copy vxrs: %lx-%lx\n", cp_start, cp_end); - if (copy_to_user(buf + buf_off, - (void *) &sa_ext->vx_regs + sa_off, - len)) - return -EFAULT; - } - } + if (MACHINE_HAS_VX) + save_vx_regs_safe(sa_ext->vx_regs); return 0; } @@ -326,126 +164,6 @@ static void release_hsa(void) hsa_available = 0; } -/* - * Read routine for zcore character device - * First 4K are dump header - * Next 32MB are HSA Memory - * Rest is read from absolute Memory - */ -static ssize_t zcore_read(struct file *file, char __user *buf, size_t count, - loff_t *ppos) -{ - unsigned long mem_start; /* Start address in memory */ - size_t mem_offs; /* Offset in dump memory */ - size_t hdr_count; /* Size of header part of output buffer */ - size_t size; - int rc; - - mutex_lock(&zcore_mutex); - - if (*ppos > (sys_info.mem_size + HEADER_SIZE)) { - rc = -EINVAL; - goto fail; - } - - count = min(count, (size_t) (sys_info.mem_size + HEADER_SIZE - *ppos)); - - /* Copy dump header */ - if (*ppos < HEADER_SIZE) { - size = min(count, (size_t) (HEADER_SIZE - *ppos)); - if (copy_to_user(buf, &zcore_header + *ppos, size)) { - rc = -EFAULT; - goto fail; - } - hdr_count = size; - mem_start = 0; - } else { - hdr_count = 0; - mem_start = *ppos - HEADER_SIZE; - } - - mem_offs = 0; - - /* Copy from HSA data */ - if (*ppos < sclp.hsa_size + HEADER_SIZE) { - size = min((count - hdr_count), - (size_t) (sclp.hsa_size - mem_start)); - rc = memcpy_hsa_user(buf + hdr_count, mem_start, size); - if (rc) - goto fail; - - mem_offs += size; - } - - /* Copy from real mem */ - size = count - mem_offs - hdr_count; - rc = copy_to_user_real(buf + hdr_count + mem_offs, - (void *) mem_start + mem_offs, size); - if (rc) - goto fail; - - /* - * Since s390 dump analysis tools like lcrash or crash - * expect register sets in the prefix pages of the cpus, - * we copy them into the read buffer, if necessary. - * buf + hdr_count: Start of memory part of output buffer - * mem_start: Start memory address to copy from - * count - hdr_count: Size of memory area to copy - */ - if (zcore_add_lc(buf + hdr_count, mem_start, count - hdr_count)) { - rc = -EFAULT; - goto fail; - } - *ppos += count; -fail: - mutex_unlock(&zcore_mutex); - return (rc < 0) ? rc : count; -} - -static int zcore_open(struct inode *inode, struct file *filp) -{ - if (!hsa_available) - return -ENODATA; - else - return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; -} - -static int zcore_release(struct inode *inode, struct file *filep) -{ - if (hsa_available) - release_hsa(); - return 0; -} - -static loff_t zcore_lseek(struct file *file, loff_t offset, int orig) -{ - loff_t rc; - - mutex_lock(&zcore_mutex); - switch (orig) { - case 0: - file->f_pos = offset; - rc = file->f_pos; - break; - case 1: - file->f_pos += offset; - rc = file->f_pos; - break; - default: - rc = -EINVAL; - } - mutex_unlock(&zcore_mutex); - return rc; -} - -static const struct file_operations zcore_fops = { - .owner = THIS_MODULE, - .llseek = zcore_lseek, - .read = zcore_read, - .open = zcore_open, - .release = zcore_release, -}; - static ssize_t zcore_memmap_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) { @@ -549,50 +267,6 @@ static const struct file_operations zcore_hsa_fops = { .llseek = no_llseek, }; -static void __init set_lc_mask(struct save_area *map) -{ - memset(&map->fp_regs, 0xff, sizeof(map->fp_regs)); - memset(&map->gp_regs, 0xff, sizeof(map->gp_regs)); - memset(&map->psw, 0xff, sizeof(map->psw)); - memset(&map->pref_reg, 0xff, sizeof(map->pref_reg)); - memset(&map->fp_ctrl_reg, 0xff, sizeof(map->fp_ctrl_reg)); - memset(&map->tod_reg, 0xff, sizeof(map->tod_reg)); - memset(&map->timer, 0xff, sizeof(map->timer)); - memset(&map->clk_cmp, 0xff, sizeof(map->clk_cmp)); - memset(&map->acc_regs, 0xff, sizeof(map->acc_regs)); - memset(&map->ctrl_regs, 0xff, sizeof(map->ctrl_regs)); -} - -/* - * Initialize dump globals for a given architecture - */ -static int __init sys_info_init(enum arch_id arch, unsigned long mem_end) -{ - int rc; - - switch (arch) { - case ARCH_S390X: - pr_alert("DETECTED 'S390X (64 bit) OS'\n"); - break; - case ARCH_S390: - pr_alert("DETECTED 'S390 (32 bit) OS'\n"); - break; - default: - pr_alert("0x%x is an unknown architecture.\n",arch); - return -EINVAL; - } - sys_info.sa_base = SAVE_AREA_BASE; - sys_info.sa_size = sizeof(struct save_area); - sys_info.arch = arch; - set_lc_mask(&sys_info.lc_mask); - rc = init_cpu_info(arch); - if (rc) - return rc; - sys_info.mem_size = mem_end; - - return 0; -} - static int __init check_sdias(void) { if (!sclp.hsa_size) { @@ -602,43 +276,6 @@ static int __init check_sdias(void) return 0; } -static int __init get_mem_info(unsigned long *mem, unsigned long *end) -{ - struct memblock_region *reg; - - for_each_memblock(memory, reg) { - *mem += reg->size; - *end = max_t(unsigned long, *end, reg->base + reg->size); - } - return 0; -} - -static void __init zcore_header_init(int arch, struct zcore_header *hdr, - unsigned long mem_size) -{ - u32 prefix; - int i; - - if (arch == ARCH_S390X) - hdr->arch_id = DUMP_ARCH_S390X; - else - hdr->arch_id = DUMP_ARCH_S390; - hdr->mem_size = mem_size; - hdr->rmem_size = mem_size; - hdr->mem_end = sys_info.mem_size; - hdr->num_pages = mem_size / PAGE_SIZE; - hdr->tod = get_tod_clock(); - get_cpu_id(&hdr->cpu_id); - for (i = 0; i < dump_save_areas.count; i++) { - prefix = dump_save_areas.areas[i]->sa.pref_reg; - hdr->real_cpu_cnt++; - if (!prefix) - continue; - hdr->lc_vec[hdr->cpu_cnt] = prefix; - hdr->cpu_cnt++; - } -} - /* * Provide IPL parameter information block from either HSA or memory * for future reipl @@ -671,11 +308,9 @@ static int __init zcore_reipl_init(void) static int __init zcore_init(void) { - unsigned long mem_size, mem_end; unsigned char arch; int rc; - mem_size = mem_end = 0; if (ipl_info.type != IPL_TYPE_FCP_DUMP) return -ENODATA; if (OLDMEM_BASE) @@ -709,15 +344,11 @@ static int __init zcore_init(void) goto fail; } - rc = get_mem_info(&mem_size, &mem_end); + pr_alert("DETECTED 'S390X (64 bit) OS'\n"); + rc = init_cpu_info(); if (rc) goto fail; - rc = sys_info_init(arch, mem_end); - if (rc) - goto fail; - zcore_header_init(arch, &zcore_header, mem_size); - rc = zcore_reipl_init(); if (rc) goto fail; @@ -727,17 +358,11 @@ static int __init zcore_init(void) rc = -ENOMEM; goto fail; } - zcore_file = debugfs_create_file("mem", S_IRUSR, zcore_dir, NULL, - &zcore_fops); - if (!zcore_file) { - rc = -ENOMEM; - goto fail_dir; - } zcore_memmap_file = debugfs_create_file("memmap", S_IRUSR, zcore_dir, NULL, &zcore_memmap_fops); if (!zcore_memmap_file) { rc = -ENOMEM; - goto fail_file; + goto fail_dir; } zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir, NULL, &zcore_reipl_fops); @@ -757,8 +382,6 @@ fail_reipl_file: debugfs_remove(zcore_reipl_file); fail_memmap_file: debugfs_remove(zcore_memmap_file); -fail_file: - debugfs_remove(zcore_file); fail_dir: debugfs_remove(zcore_dir); fail: @@ -774,7 +397,6 @@ static void __exit zcore_exit(void) debugfs_remove(zcore_hsa_file); debugfs_remove(zcore_reipl_file); debugfs_remove(zcore_memmap_file); - debugfs_remove(zcore_file); debugfs_remove(zcore_dir); diag308(DIAG308_REL_HSA, NULL); } -- 2.20.1