cregit-Linux how code gets into the kernel

Release 4.7 drivers/s390/char/zcore.c

/*
 * 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.txt
 *
 * 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/miscdevice.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/memblock.h>

#include <asm/asm-offsets.h>
#include <asm/ipl.h>
#include <asm/sclp.h>
#include <asm/setup.h>
#include <asm/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 *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; }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu8171.68%266.67%
martin schwidefskymartin schwidefsky3228.32%133.33%
Total113100.00%3100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky5854.72%133.33%
michael holzheumichael holzheu4845.28%266.67%
Total106100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu4164.06%233.33%
martin schwidefskymartin schwidefsky2234.38%350.00%
heiko carstensheiko carstens11.56%116.67%
Total64100.00%6100.00%

/* * Release the HSA */
static void release_hsa(void) { diag308(DIAG308_REL_HSA, NULL); hsa_available = 0; }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky19100.00%2100.00%
Total19100.00%2100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky45100.00%2100.00%
Total45100.00%2100.00%


static int zcore_memmap_open(struct inode *inode, struct file *filp) { struct memblock_region *reg; char *buf; int i = 0; buf = kzalloc(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); }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky9889.09%375.00%
frank munzertfrank munzert1210.91%125.00%
Total110100.00%4100.00%


static int zcore_memmap_release(struct inode *inode, struct file *filp) { kfree(filp->private_data); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
frank munzertfrank munzert26100.00%1100.00%
Total26100.00%1100.00%

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 (ipl_block) { diag308(DIAG308_SET, ipl_block); diag308(DIAG308_IPL, NULL); } return count; }

Contributors

PersonTokensPropCommitsCommitProp
frank munzertfrank munzert47100.00%1100.00%
Total47100.00%1100.00%


static int zcore_reipl_open(struct inode *inode, struct file *filp) { return nonseekable_open(inode, filp); }

Contributors

PersonTokensPropCommitsCommitProp
frank munzertfrank munzert1875.00%150.00%
martin schwidefskymartin schwidefsky625.00%150.00%
Total24100.00%2100.00%


static int zcore_reipl_release(struct inode *inode, struct file *filp) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
frank munzertfrank munzert19100.00%1100.00%
Total19100.00%1100.00%

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)); }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu7796.25%150.00%
david hildenbranddavid hildenbrand33.75%150.00%
Total80100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu70100.00%1100.00%
Total70100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu2790.00%375.00%
david hildenbranddavid hildenbrand310.00%125.00%
Total30100.00%4100.00%

/* * 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; ipl_block = (void *) __get_free_page(GFP_KERNEL); if (!ipl_block) return -ENOMEM; if (ipib_info.ipib < sclp.hsa_size) rc = memcpy_hsa_kernel(ipl_block, ipib_info.ipib, PAGE_SIZE); else rc = memcpy_real(ipl_block, (void *) ipib_info.ipib, PAGE_SIZE); if (rc || csum_partial(ipl_block, ipl_block->hdr.len, 0) != ipib_info.checksum) { TRACE("Checksum does not match\n"); free_page((unsigned long) ipl_block); ipl_block = NULL; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
frank munzertfrank munzert14694.81%240.00%
michael holzheumichael holzheu53.25%240.00%
david hildenbranddavid hildenbrand31.95%120.00%
Total154100.00%5100.00%


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("DETECTED 'S390X (64 bit) OS'\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; }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu26169.97%337.50%
frank munzertfrank munzert8422.52%225.00%
heiko carstensheiko carstens236.17%225.00%
martin schwidefskymartin schwidefsky51.34%112.50%
Total373100.00%8100.00%


static void __exit zcore_exit(void) { debug_unregister(zcore_dbf); sclp_sdias_exit(); free_page((unsigned long) ipl_block); debugfs_remove(zcore_hsa_file); debugfs_remove(zcore_reipl_file); debugfs_remove(zcore_memmap_file); debugfs_remove(zcore_dir); diag308(DIAG308_REL_HSA, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu2852.83%250.00%
frank munzertfrank munzert2445.28%125.00%
heiko carstensheiko carstens11.89%125.00%
Total53100.00%4100.00%

MODULE_AUTHOR("Copyright IBM Corp. 2003,2008"); MODULE_DESCRIPTION("zcore module for zfcpdump support"); MODULE_LICENSE("GPL"); subsys_initcall(zcore_init); module_exit(zcore_exit);

Overall Contributors

PersonTokensPropCommitsCommitProp
michael holzheumichael holzheu76747.32%1035.71%
frank munzertfrank munzert47829.49%310.71%
martin schwidefskymartin schwidefsky31619.49%621.43%
heiko carstensheiko carstens352.16%517.86%
arnd bergmannarnd bergmann100.62%13.57%
david hildenbranddavid hildenbrand90.56%13.57%
philipp hachtmannphilipp hachtmann30.19%13.57%
tejun heotejun heo30.19%13.57%
Total1621100.00%28100.00%
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