forked from rpms/kernel
		
	
		
			
				
	
	
		
			723 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			723 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 973e23bf27b0b2e5021321357fc570cccea3104c Mon Sep 17 00:00:00 2001
 | |
| From: Dave Anderson <anderson@redhat.com>
 | |
| Date: Tue, 26 Nov 2013 12:42:46 -0500
 | |
| Subject: [PATCH] crash-driver
 | |
| 
 | |
| Bugzilla: N/A
 | |
| Upstream-status: Fedora mustard
 | |
| ---
 | |
|  arch/arm/include/asm/crash-driver.h     |   6 ++
 | |
|  arch/arm64/include/asm/crash-driver.h   |   6 ++
 | |
|  arch/ia64/include/asm/crash-driver.h    |  90 ++++++++++++++++++++++
 | |
|  arch/ia64/kernel/ia64_ksyms.c           |   3 +
 | |
|  arch/powerpc/include/asm/crash-driver.h |   6 ++
 | |
|  arch/s390/include/asm/crash-driver.h    |  60 +++++++++++++++
 | |
|  arch/s390/mm/maccess.c                  |   2 +
 | |
|  arch/x86/include/asm/crash-driver.h     |   6 ++
 | |
|  drivers/char/Kconfig                    |   3 +
 | |
|  drivers/char/Makefile                   |   2 +
 | |
|  drivers/char/crash.c                    | 128 ++++++++++++++++++++++++++++++++
 | |
|  include/asm-generic/crash-driver.h      |  72 ++++++++++++++++++
 | |
|  12 files changed, 384 insertions(+)
 | |
|  create mode 100644 arch/arm/include/asm/crash-driver.h
 | |
|  create mode 100644 arch/arm64/include/asm/crash-driver.h
 | |
|  create mode 100644 arch/ia64/include/asm/crash-driver.h
 | |
|  create mode 100644 arch/powerpc/include/asm/crash-driver.h
 | |
|  create mode 100644 arch/s390/include/asm/crash-driver.h
 | |
|  create mode 100644 arch/x86/include/asm/crash-driver.h
 | |
|  create mode 100644 drivers/char/crash.c
 | |
|  create mode 100644 include/asm-generic/crash-driver.h
 | |
| 
 | |
| diff --git a/arch/arm/include/asm/crash-driver.h b/arch/arm/include/asm/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..06e7ae9
 | |
| --- /dev/null
 | |
| +++ b/arch/arm/include/asm/crash-driver.h
 | |
| @@ -0,0 +1,6 @@
 | |
| +#ifndef _ARM_CRASH_H
 | |
| +#define _ARM_CRASH_H
 | |
| +
 | |
| +#include <asm-generic/crash-driver.h>
 | |
| +
 | |
| +#endif /* _ARM_CRASH_H */
 | |
| diff --git a/arch/arm64/include/asm/crash-driver.h b/arch/arm64/include/asm/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..43b26da
 | |
| --- /dev/null
 | |
| +++ b/arch/arm64/include/asm/crash-driver.h
 | |
| @@ -0,0 +1,6 @@
 | |
| +#ifndef _ARM64_CRASH_H
 | |
| +#define _ARM64_CRASH_H
 | |
| +
 | |
| +#include <asm-generic/crash-driver.h>
 | |
| +
 | |
| +#endif /* _ARM64_CRASH_H */
 | |
| diff --git a/arch/ia64/include/asm/crash-driver.h b/arch/ia64/include/asm/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..404bcb9
 | |
| --- /dev/null
 | |
| +++ b/arch/ia64/include/asm/crash-driver.h
 | |
| @@ -0,0 +1,90 @@
 | |
| +#ifndef _ASM_IA64_CRASH_H
 | |
| +#define _ASM_IA64_CRASH_H
 | |
| +
 | |
| +/*
 | |
| + * linux/include/asm-ia64/crash-driver.h
 | |
| + *
 | |
| + * Copyright (c) 2004 Red Hat, Inc. All rights reserved.
 | |
| + *
 | |
| + * This program is free software; you can redistribute it and/or modify
 | |
| + * it under the terms of the GNU General Public License as published by
 | |
| + * the Free Software Foundation; either version 2, or (at your option)
 | |
| + * any later version.
 | |
| + *
 | |
| + * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 | |
| + *
 | |
| + */
 | |
| +
 | |
| +#ifdef __KERNEL__
 | |
| +
 | |
| +#include <linux/efi.h>
 | |
| +#include <linux/mm.h>
 | |
| +#include <asm/mmzone.h>
 | |
| +
 | |
| +static inline void *
 | |
| +map_virtual(u64 offset, struct page **pp)
 | |
| +{
 | |
| +	struct page *page;
 | |
| +	unsigned long pfn;
 | |
| +	u32 type;
 | |
| +
 | |
| +	if (REGION_NUMBER(offset) == 5) {
 | |
| +		char byte;
 | |
| +
 | |
| +		if (__get_user(byte, (char *)offset) == 0)
 | |
| +			return (void *)offset;
 | |
| +		else
 | |
| +			return NULL;
 | |
| +	}
 | |
| +
 | |
| +	switch (type = efi_mem_type(offset))
 | |
| +	{
 | |
| +	case EFI_LOADER_CODE:
 | |
| +	case EFI_LOADER_DATA:
 | |
| +	case EFI_BOOT_SERVICES_CODE:
 | |
| +	case EFI_BOOT_SERVICES_DATA:
 | |
| +	case EFI_CONVENTIONAL_MEMORY:
 | |
| +		break;
 | |
| +
 | |
| +	default:
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: invalid memory type for %lx: %d\n",
 | |
| +			offset, type);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	pfn = offset >> PAGE_SHIFT;
 | |
| +
 | |
| +	if (!pfn_valid(pfn)) {
 | |
| +		printk(KERN_INFO
 | |
| +			"crash memory driver: invalid pfn: %lx )\n", pfn);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	page = pfn_to_page(pfn);
 | |
| +
 | |
| +	if (!page->virtual) {
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: offset: %lx page: %lx page->virtual: NULL\n",
 | |
| +			offset, (unsigned long)page);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	return (page->virtual + (offset & (PAGE_SIZE-1)));
 | |
| +}
 | |
| +
 | |
| +static inline void unmap_virtual(struct page *page)
 | |
| +{
 | |
| +	return;
 | |
| +}
 | |
| +
 | |
| +#endif /* __KERNEL__ */
 | |
| +
 | |
| +#endif /* _ASM_IA64_CRASH_H */
 | |
| diff --git a/arch/ia64/kernel/ia64_ksyms.c b/arch/ia64/kernel/ia64_ksyms.c
 | |
| index d111248..b14b4c6 100644
 | |
| --- a/arch/ia64/kernel/ia64_ksyms.c
 | |
| +++ b/arch/ia64/kernel/ia64_ksyms.c
 | |
| @@ -9,3 +9,6 @@
 | |
|  EXPORT_SYMBOL(min_low_pfn);	/* defined by bootmem.c, but not exported by generic code */
 | |
|  EXPORT_SYMBOL(max_low_pfn);	/* defined by bootmem.c, but not exported by generic code */
 | |
|  #endif
 | |
| +
 | |
| +#include <linux/efi.h>
 | |
| +EXPORT_SYMBOL_GPL(efi_mem_type);
 | |
| diff --git a/arch/powerpc/include/asm/crash-driver.h b/arch/powerpc/include/asm/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..50092d9
 | |
| --- /dev/null
 | |
| +++ b/arch/powerpc/include/asm/crash-driver.h
 | |
| @@ -0,0 +1,6 @@
 | |
| +#ifndef _PPC64_CRASH_H
 | |
| +#define _PPC64_CRASH_H
 | |
| +
 | |
| +#include <asm-generic/crash-driver.h>
 | |
| +
 | |
| +#endif /* _PPC64_CRASH_H */
 | |
| diff --git a/arch/s390/include/asm/crash-driver.h b/arch/s390/include/asm/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..552be5e
 | |
| --- /dev/null
 | |
| +++ b/arch/s390/include/asm/crash-driver.h
 | |
| @@ -0,0 +1,60 @@
 | |
| +#ifndef _S390_CRASH_H
 | |
| +#define _S390_CRASH_H
 | |
| +
 | |
| +#ifdef __KERNEL__
 | |
| +
 | |
| +#include <linux/mm.h>
 | |
| +#include <linux/highmem.h>
 | |
| +
 | |
| +/*
 | |
| + * For swapped prefix pages get bounce buffer using xlate_dev_mem_ptr()
 | |
| + */
 | |
| +static inline void *map_virtual(u64 offset, struct page **pp)
 | |
| +{
 | |
| +	struct page *page;
 | |
| +	unsigned long pfn;
 | |
| +	void *vaddr;
 | |
| +
 | |
| +	vaddr = xlate_dev_mem_ptr(offset);
 | |
| +	pfn = ((unsigned long) vaddr) >> PAGE_SHIFT;
 | |
| +	if ((unsigned long) vaddr != offset)
 | |
| +		page = pfn_to_page(pfn);
 | |
| +	else
 | |
| +		page = NULL;
 | |
| +
 | |
| +	if (!page_is_ram(pfn)) {
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: !page_is_ram(pfn: %lx)\n", pfn);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	if (!pfn_valid(pfn)) {
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: invalid pfn: %lx )\n", pfn);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	*pp = page;
 | |
| +	return vaddr;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Free bounce buffer if necessary
 | |
| + */
 | |
| +static inline void unmap_virtual(struct page *page)
 | |
| +{
 | |
| +	void *vaddr;
 | |
| +
 | |
| +	if (page) {
 | |
| +		/*
 | |
| +		 * Because for bounce buffers vaddr will never be 0
 | |
| +		 * unxlate_dev_mem_ptr() will always free the bounce buffer.
 | |
| +		 */
 | |
| +		vaddr = (void *)(page_to_pfn(page) << PAGE_SHIFT);
 | |
| +		unxlate_dev_mem_ptr(0, vaddr);
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +#endif /* __KERNEL__ */
 | |
| +
 | |
| +#endif /* _S390_CRASH_H */
 | |
| diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
 | |
| index 792f9c6..3197995 100644
 | |
| --- a/arch/s390/mm/maccess.c
 | |
| +++ b/arch/s390/mm/maccess.c
 | |
| @@ -201,6 +201,7 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
 | |
|  	put_online_cpus();
 | |
|  	return bounce;
 | |
|  }
 | |
| +EXPORT_SYMBOL_GPL(xlate_dev_mem_ptr);
 | |
|  
 | |
|  /*
 | |
|   * Free converted buffer for /dev/mem access (if necessary)
 | |
| @@ -210,3 +211,4 @@ void unxlate_dev_mem_ptr(phys_addr_t addr, void *buf)
 | |
|  	if ((void *) addr != buf)
 | |
|  		free_page((unsigned long) buf);
 | |
|  }
 | |
| +EXPORT_SYMBOL_GPL(unxlate_dev_mem_ptr);
 | |
| diff --git a/arch/x86/include/asm/crash-driver.h b/arch/x86/include/asm/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..fd4736e
 | |
| --- /dev/null
 | |
| +++ b/arch/x86/include/asm/crash-driver.h
 | |
| @@ -0,0 +1,6 @@
 | |
| +#ifndef _X86_CRASH_H
 | |
| +#define _X86_CRASH_H
 | |
| +
 | |
| +#include <asm-generic/crash-driver.h>
 | |
| +
 | |
| +#endif /* _X86_CRASH_H */
 | |
| diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
 | |
| index dcc0973..99b99d5 100644
 | |
| --- a/drivers/char/Kconfig
 | |
| +++ b/drivers/char/Kconfig
 | |
| @@ -4,6 +4,9 @@
 | |
|  
 | |
|  menu "Character devices"
 | |
|  
 | |
| +config CRASH
 | |
| +	tristate "Crash Utility memory driver"
 | |
| +
 | |
|  source "drivers/tty/Kconfig"
 | |
|  
 | |
|  config DEVMEM
 | |
| diff --git a/drivers/char/Makefile b/drivers/char/Makefile
 | |
| index 6e6c244..29cc9c8 100644
 | |
| --- a/drivers/char/Makefile
 | |
| +++ b/drivers/char/Makefile
 | |
| @@ -58,3 +58,5 @@ js-rtc-y = rtc.o
 | |
|  obj-$(CONFIG_XILLYBUS)		+= xillybus/
 | |
|  obj-$(CONFIG_POWERNV_OP_PANEL)	+= powernv-op-panel.o
 | |
|  obj-$(CONFIG_ADI)		+= adi.o
 | |
| +
 | |
| +obj-$(CONFIG_CRASH)            += crash.o
 | |
| diff --git a/drivers/char/crash.c b/drivers/char/crash.c
 | |
| new file mode 100644
 | |
| index 0000000..085378a
 | |
| --- /dev/null
 | |
| +++ b/drivers/char/crash.c
 | |
| @@ -0,0 +1,128 @@
 | |
| +/*
 | |
| + *  linux/drivers/char/crash.c
 | |
| + *
 | |
| + *  Copyright (C) 2004  Dave Anderson <anderson@redhat.com>
 | |
| + *  Copyright (C) 2004  Red Hat, Inc.
 | |
| + */
 | |
| +
 | |
| +/******************************************************************************
 | |
| + *
 | |
| + *   This program is free software; you can redistribute it and/or modify
 | |
| + *   it under the terms of the GNU General Public License as published by
 | |
| + *   the Free Software Foundation; either version 2, or (at your option)
 | |
| + *   any later version.
 | |
| + *
 | |
| + *   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., 675 Mass Ave, Cambridge, MA 02139, USA.
 | |
| + *
 | |
| + *****************************************************************************/
 | |
| +
 | |
| +#include <linux/module.h>
 | |
| +#include <linux/types.h>
 | |
| +#include <linux/miscdevice.h>
 | |
| +#include <linux/init.h>
 | |
| +#include <asm/io.h>
 | |
| +#include <asm/uaccess.h>
 | |
| +#include <asm/types.h>
 | |
| +#include <asm/crash-driver.h>
 | |
| +
 | |
| +#define CRASH_VERSION   "1.0"
 | |
| +
 | |
| +/*
 | |
| + *  These are the file operation functions that allow crash utility
 | |
| + *  access to physical memory.
 | |
| + */
 | |
| +
 | |
| +static loff_t
 | |
| +crash_llseek(struct file * file, loff_t offset, int orig)
 | |
| +{
 | |
| +	switch (orig) {
 | |
| +	case 0:
 | |
| +		file->f_pos = offset;
 | |
| +		return file->f_pos;
 | |
| +	case 1:
 | |
| +		file->f_pos += offset;
 | |
| +		return file->f_pos;
 | |
| +	default:
 | |
| +		return -EINVAL;
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + *  Determine the page address for an address offset value,
 | |
| + *  get a virtual address for it, and copy it out.
 | |
| + *  Accesses must fit within a page.
 | |
| + */
 | |
| +static ssize_t
 | |
| +crash_read(struct file *file, char *buf, size_t count, loff_t *poff)
 | |
| +{
 | |
| +	void *vaddr;
 | |
| +	struct page *page;
 | |
| +	u64 offset;
 | |
| +	ssize_t read;
 | |
| +
 | |
| +	offset = *poff;
 | |
| +	if (offset >> PAGE_SHIFT != (offset+count-1) >> PAGE_SHIFT)
 | |
| +		return -EINVAL;
 | |
| +
 | |
| +	vaddr = map_virtual(offset, &page);
 | |
| +	if (!vaddr)
 | |
| +		return -EFAULT;
 | |
| +
 | |
| +	if (copy_to_user(buf, vaddr, count)) {
 | |
| +		unmap_virtual(page);
 | |
| +		return -EFAULT;
 | |
| +	}
 | |
| +	unmap_virtual(page);
 | |
| +
 | |
| +	read = count;
 | |
| +	*poff += read;
 | |
| +	return read;
 | |
| +}
 | |
| +
 | |
| +static struct file_operations crash_fops = {
 | |
| +	.owner = THIS_MODULE,
 | |
| +	.llseek = crash_llseek,
 | |
| +	.read = crash_read,
 | |
| +};
 | |
| +
 | |
| +static struct miscdevice crash_dev = {
 | |
| +	MISC_DYNAMIC_MINOR,
 | |
| +	"crash",
 | |
| +	&crash_fops
 | |
| +};
 | |
| +
 | |
| +static int __init
 | |
| +crash_init(void)
 | |
| +{
 | |
| +	int ret;
 | |
| +
 | |
| +	ret = misc_register(&crash_dev);
 | |
| +	if (ret) {
 | |
| +		printk(KERN_ERR
 | |
| +		    "crash memory driver: cannot misc_register (MISC_DYNAMIC_MINOR)\n");
 | |
| +		goto out;
 | |
| +	}
 | |
| +
 | |
| +	ret = 0;
 | |
| +	printk(KERN_INFO "crash memory driver: version %s\n", CRASH_VERSION);
 | |
| +out:
 | |
| +	return ret;
 | |
| +}
 | |
| +
 | |
| +static void __exit
 | |
| +crash_cleanup_module(void)
 | |
| +{
 | |
| +	misc_deregister(&crash_dev);
 | |
| +}
 | |
| +
 | |
| +module_init(crash_init);
 | |
| +module_exit(crash_cleanup_module);
 | |
| +
 | |
| +MODULE_LICENSE("GPL");
 | |
| diff --git a/include/asm-generic/crash-driver.h b/include/asm-generic/crash-driver.h
 | |
| new file mode 100644
 | |
| index 0000000..25ab986
 | |
| --- /dev/null
 | |
| +++ b/include/asm-generic/crash-driver.h
 | |
| @@ -0,0 +1,72 @@
 | |
| +#ifndef __CRASH_H__
 | |
| +#define __CRASH_H__
 | |
| +
 | |
| +/*
 | |
| + * include/linux/crash-driver.h
 | |
| + *
 | |
| + * Copyright (c) 2013 Red Hat, Inc. All rights reserved.
 | |
| + *
 | |
| + * This program is free software; you can redistribute it and/or modify
 | |
| + * it under the terms of the GNU General Public License as published by
 | |
| + * the Free Software Foundation; either version 2, or (at your option)
 | |
| + * any later version.
 | |
| + *
 | |
| + * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 | |
| + *
 | |
| + */
 | |
| +
 | |
| +#ifdef __KERNEL__
 | |
| +
 | |
| +#include <linux/mm.h>
 | |
| +#include <linux/highmem.h>
 | |
| +
 | |
| +static inline void *
 | |
| +map_virtual(u64 offset, struct page **pp)
 | |
| +{
 | |
| +	struct page *page;
 | |
| +	unsigned long pfn;
 | |
| +	void *vaddr;
 | |
| +
 | |
| +	pfn = (unsigned long)(offset >> PAGE_SHIFT);
 | |
| +
 | |
| +	if (!page_is_ram(pfn)) {
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: !page_is_ram(pfn: %lx)\n", pfn);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	if (!pfn_valid(pfn)) {
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: invalid pfn: %lx )\n", pfn);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	page = pfn_to_page(pfn);
 | |
| +
 | |
| +	vaddr = kmap(page);
 | |
| +	if (!vaddr) {
 | |
| +		printk(KERN_INFO
 | |
| +		    "crash memory driver: pfn: %lx kmap(page: %lx) failed\n",
 | |
| +			pfn, (unsigned long)page);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	*pp = page;
 | |
| +	return (vaddr + (offset & (PAGE_SIZE-1)));
 | |
| +}
 | |
| +
 | |
| +static inline void unmap_virtual(struct page *page)
 | |
| +{
 | |
| +	kunmap(page);
 | |
| +}
 | |
| +
 | |
| +#endif /* __KERNEL__ */
 | |
| +
 | |
| +#endif /* __CRASH_H__ */
 | |
| -- 
 | |
| 2.7.4
 | |
| 
 | |
| From 23d8bd48303acda2d3a95a3e1a662784a4fa9fcd Mon Sep 17 00:00:00 2001
 | |
| From: Fedora Kernel Team <kernel-team@fedoraproject.org>
 | |
| Date: Tue, 20 Sep 2016 19:39:46 +0200
 | |
| Subject: [PATCH] Update of crash driver to handle CONFIG_HARDENED_USERCOPY and
 | |
|  to restrict the supported architectures.
 | |
| 
 | |
| ---
 | |
|  drivers/char/Kconfig |  1 +
 | |
|  drivers/char/crash.c | 33 ++++++++++++++++++++++++++++++---
 | |
|  2 files changed, 31 insertions(+), 3 deletions(-)
 | |
| 
 | |
| diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
 | |
| index 99b99d5..be6a3ae 100644
 | |
| --- a/drivers/char/Kconfig
 | |
| +++ b/drivers/char/Kconfig
 | |
| @@ -6,6 +6,7 @@ menu "Character devices"
 | |
|  
 | |
|  config CRASH
 | |
|  	tristate "Crash Utility memory driver"
 | |
| +	depends on X86_32 || X86_64 || ARM || ARM64 || PPC64 || S390
 | |
|  
 | |
|  source "drivers/tty/Kconfig"
 | |
|  
 | |
| diff --git a/drivers/char/crash.c b/drivers/char/crash.c
 | |
| index 085378a..0258bf8 100644
 | |
| --- a/drivers/char/crash.c
 | |
| +++ b/drivers/char/crash.c
 | |
| @@ -32,7 +32,7 @@
 | |
|  #include <asm/types.h>
 | |
|  #include <asm/crash-driver.h>
 | |
|  
 | |
| -#define CRASH_VERSION   "1.0"
 | |
| +#define CRASH_VERSION   "1.2"
 | |
|  
 | |
|  /*
 | |
|   *  These are the file operation functions that allow crash utility
 | |
| @@ -66,6 +66,7 @@ crash_read(struct file *file, char *buf, size_t count, loff_t *poff)
 | |
|  	struct page *page;
 | |
|  	u64 offset;
 | |
|  	ssize_t read;
 | |
| +	char *buffer = file->private_data;
 | |
|  
 | |
|  	offset = *poff;
 | |
|  	if (offset >> PAGE_SHIFT != (offset+count-1) >> PAGE_SHIFT)
 | |
| @@ -74,8 +75,12 @@ crash_read(struct file *file, char *buf, size_t count, loff_t *poff)
 | |
|  	vaddr = map_virtual(offset, &page);
 | |
|  	if (!vaddr)
 | |
|  		return -EFAULT;
 | |
| -
 | |
| -	if (copy_to_user(buf, vaddr, count)) {
 | |
| +	/*
 | |
| +	 * Use bounce buffer to bypass the CONFIG_HARDENED_USERCOPY
 | |
| +	 * kernel text restriction.
 | |
| +	*/
 | |
| +	memcpy(buffer, (char *)vaddr, count);
 | |
| +	if (copy_to_user(buf, buffer, count)) {
 | |
|  		unmap_virtual(page);
 | |
|  		return -EFAULT;
 | |
|  	}
 | |
| @@ -86,10 +91,32 @@ crash_read(struct file *file, char *buf, size_t count, loff_t *poff)
 | |
|  	return read;
 | |
|  }
 | |
|  
 | |
| +static int
 | |
| +crash_open(struct inode * inode, struct file * filp)
 | |
| +{
 | |
| +	if (!capable(CAP_SYS_RAWIO))
 | |
| +		return -EPERM;
 | |
| +
 | |
| +	filp->private_data = (void *)__get_free_page(GFP_KERNEL);
 | |
| +	if (!filp->private_data)
 | |
| +		return -ENOMEM;
 | |
| +
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +static int
 | |
| +crash_release(struct inode *inode, struct file *filp)
 | |
| +{
 | |
| +	free_pages((unsigned long)filp->private_data, 0);
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
|  static struct file_operations crash_fops = {
 | |
|  	.owner = THIS_MODULE,
 | |
|  	.llseek = crash_llseek,
 | |
|  	.read = crash_read,
 | |
| +	.open = crash_open,
 | |
| +	.release = crash_release,
 | |
|  };
 | |
|  
 | |
|  static struct miscdevice crash_dev = {
 | |
| -- 
 | |
| 2.7.4
 | |
| 
 | |
| From: Dave Anderson <anderson@redhat.com>
 | |
| Date: Fri, 18 Nov 2016 11:52:35 -0500
 | |
| Cc: onestero@redhat.com
 | |
| Subject: [PATCH v2] Restore live system crash analysis for ARM64
 | |
| 
 | |
| This v2 version simplifies the copy out of the kimage_voffset value
 | |
| to user-space per Oleg's suggestion.
 | |
| 
 | |
| Upstream status: N/A
 | |
| 
 | |
| Test: v2 version tested successfully with a modified crash utility
 | |
| 
 | |
| The following Linux 4.6 commit breaks support for live system
 | |
| crash analysis on ARM64:
 | |
| 
 | |
|    commit a7f8de168ace487fa7b88cb154e413cf40e87fc6
 | |
|    Author: Ard Biesheuvel <ard.biesheuvel@linaro.org>
 | |
|    arm64: allow kernel Image to be loaded anywhere in physical memory
 | |
| 
 | |
| The patchset drastically modified the kernel's virtual memory layout,
 | |
| where notably the static kernel text and data image was moved from the
 | |
| unity mapped region into the vmalloc region.  Prior to Linux 4.6,
 | |
| the kernel's __virt_to_phys() function was this:
 | |
| 
 | |
|  #define __virt_to_phys(x)  (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
 | |
| 
 | |
| When running on a live system, the crash utility could determine PAGE_OFFSET
 | |
| by looking at the virtual addresses compiled into the vmlinux file, and
 | |
| PHYS_OFFSET can be determined by looking at /proc/iomem.
 | |
| 
 | |
| As of Linux 4.6, it is done differently:
 | |
| 
 | |
|  #define __virt_to_phys(x) ({                                            \
 | |
|         phys_addr_t __x = (phys_addr_t)(x);                             \
 | |
|         __x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET :   \
 | |
|                                  (__x - kimage_voffset); })
 | |
| 
 | |
| The PAGE_OFFSET/PHYS_OFFSET section of the conditional expression is for
 | |
| traditional unity-mapped virtual addresses, but kernel text and static
 | |
| data requires the new "kimage_voffset" variable.  Unfortunately, the
 | |
| contents of the new "kimage_voffset" variable is not available or
 | |
| calculatable from a user-space perspective, even with root privileges.
 | |
| 
 | |
| At least the ARM64 developers made its contents available to modules
 | |
| with an EXPORT_SYMBOL(kimage_voffset) declaration.  Accordingly, with
 | |
| a modification to the /dev/crash driver to return its contents, the
 | |
| crash utility can run on a live system.
 | |
| 
 | |
| The patch allows for architecture-specific DEV_CRASH_ARCH_DATA ioctls
 | |
| to be created, where this is the first instance of one.
 | |
| 
 | |
| 
 | |
| ---
 | |
|  arch/arm64/include/asm/crash-driver.h | 16 ++++++++++++++++
 | |
|  drivers/char/crash.c                  | 13 ++++++++++++-
 | |
|  2 files changed, 28 insertions(+), 1 deletion(-)
 | |
| 
 | |
| diff --git a/arch/arm64/include/asm/crash-driver.h b/arch/arm64/include/asm/crash-driver.h
 | |
| index 43b26da..fe68e7c 100644
 | |
| --- a/arch/arm64/include/asm/crash-driver.h
 | |
| +++ b/arch/arm64/include/asm/crash-driver.h
 | |
| @@ -3,4 +3,20 @@
 | |
|  
 | |
|  #include <asm-generic/crash-driver.h>
 | |
|  
 | |
| +#define DEV_CRASH_ARCH_DATA _IOR('c', 1, long)
 | |
| +
 | |
| +static long
 | |
| +crash_arch_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 | |
| +{
 | |
| +	extern u64 kimage_voffset;
 | |
| +
 | |
| +	switch (cmd)
 | |
| +	{
 | |
| +	case DEV_CRASH_ARCH_DATA:
 | |
| +		return put_user(kimage_voffset, (unsigned long __user *)arg);
 | |
| +	default:
 | |
| +		return -EINVAL;
 | |
| +	}
 | |
| +}
 | |
| +
 | |
|  #endif /* _ARM64_CRASH_H */
 | |
| diff --git a/drivers/char/crash.c b/drivers/char/crash.c
 | |
| index 0258bf8..dfb767c 100644
 | |
| --- a/drivers/char/crash.c
 | |
| +++ b/drivers/char/crash.c
 | |
| @@ -32,7 +32,7 @@
 | |
|  #include <asm/types.h>
 | |
|  #include <asm/crash-driver.h>
 | |
|  
 | |
| -#define CRASH_VERSION   "1.2"
 | |
| +#define CRASH_VERSION   "1.3"
 | |
|  
 | |
|  /*
 | |
|   *  These are the file operation functions that allow crash utility
 | |
| @@ -111,10 +111,21 @@ crash_release(struct inode *inode, struct file *filp)
 | |
|  	return 0;
 | |
|  }
 | |
|  
 | |
| +static long
 | |
| +crash_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 | |
| +{
 | |
| +#ifdef DEV_CRASH_ARCH_DATA
 | |
| +	return crash_arch_ioctl(file, cmd, arg);
 | |
| +#else
 | |
| +	return -EINVAL;
 | |
| +#endif
 | |
| +}
 | |
| +
 | |
|  static struct file_operations crash_fops = {
 | |
|  	.owner = THIS_MODULE,
 | |
|  	.llseek = crash_llseek,
 | |
|  	.read = crash_read,
 | |
| +	.unlocked_ioctl = crash_ioctl,
 | |
|  	.open = crash_open,
 | |
|  	.release = crash_release,
 | |
|  };
 | |
| -- 
 | |
| 1.8.3.1
 | |
| 
 |