drivers/s390/char/zcore.c - linux - Git at Google

 // 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 <linux/init.h>
 #include <linux/slab.h>
 #include <linux/debugfs.h>
 #include <linux/memblock.h>

 #include <asm/asm-offsets.h>
 #include <asm/ipl.h>
 #include <asm/sclp.h>
 #include <asm/setup.h>
 #include <linux/uaccess.h>
 #include <asm/debug.h>
 #include <asm/processor.h>
 #include <asm/irqflags.h>
 #include <asm/checksum.h>
 #include <asm/os_info.h>
 #include <asm/switch_to.h>
 #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);
	// 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 <linux/init.h>
	#include <linux/slab.h>
	#include <linux/debugfs.h>
	#include <linux/memblock.h>

	#include <asm/asm-offsets.h>
	#include <asm/ipl.h>
	#include <asm/sclp.h>
	#include <asm/setup.h>
	#include <linux/uaccess.h>
	#include <asm/debug.h>
	#include <asm/processor.h>
	#include <asm/irqflags.h>
	#include <asm/checksum.h>
	#include <asm/os_info.h>
	#include <asm/switch_to.h>
	#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);