723 lines
19 KiB
Diff
723 lines
19 KiB
Diff
From 973e23bf27b0b2e5021321357fc570cccea3104c Mon Sep 17 00:00:00 2001
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|
From: Dave Anderson <anderson@redhat.com>
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Date: Tue, 26 Nov 2013 12:42:46 -0500
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Subject: [PATCH] crash-driver
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Bugzilla: N/A
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Upstream-status: Fedora mustard
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---
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|
arch/arm/include/asm/crash-driver.h | 6 ++
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arch/arm64/include/asm/crash-driver.h | 6 ++
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arch/ia64/include/asm/crash-driver.h | 90 ++++++++++++++++++++++
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arch/ia64/kernel/ia64_ksyms.c | 3 +
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arch/powerpc/include/asm/crash-driver.h | 6 ++
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arch/s390/include/asm/crash-driver.h | 60 +++++++++++++++
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arch/s390/mm/maccess.c | 2 +
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arch/x86/include/asm/crash-driver.h | 6 ++
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drivers/char/Kconfig | 3 +
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drivers/char/Makefile | 2 +
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drivers/char/crash.c | 128 ++++++++++++++++++++++++++++++++
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include/asm-generic/crash-driver.h | 72 ++++++++++++++++++
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12 files changed, 384 insertions(+)
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create mode 100644 arch/arm/include/asm/crash-driver.h
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create mode 100644 arch/arm64/include/asm/crash-driver.h
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create mode 100644 arch/ia64/include/asm/crash-driver.h
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create mode 100644 arch/powerpc/include/asm/crash-driver.h
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create mode 100644 arch/s390/include/asm/crash-driver.h
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create mode 100644 arch/x86/include/asm/crash-driver.h
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create mode 100644 drivers/char/crash.c
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create mode 100644 include/asm-generic/crash-driver.h
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diff --git a/arch/arm/include/asm/crash-driver.h b/arch/arm/include/asm/crash-driver.h
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new file mode 100644
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index 0000000..06e7ae9
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--- /dev/null
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+++ b/arch/arm/include/asm/crash-driver.h
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@@ -0,0 +1,6 @@
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+#ifndef _ARM_CRASH_H
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+#define _ARM_CRASH_H
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+
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+#include <asm-generic/crash-driver.h>
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+
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+#endif /* _ARM_CRASH_H */
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diff --git a/arch/arm64/include/asm/crash-driver.h b/arch/arm64/include/asm/crash-driver.h
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new file mode 100644
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index 0000000..43b26da
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--- /dev/null
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+++ b/arch/arm64/include/asm/crash-driver.h
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@@ -0,0 +1,6 @@
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+#ifndef _ARM64_CRASH_H
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+#define _ARM64_CRASH_H
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+
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+#include <asm-generic/crash-driver.h>
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+
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+#endif /* _ARM64_CRASH_H */
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diff --git a/arch/ia64/include/asm/crash-driver.h b/arch/ia64/include/asm/crash-driver.h
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new file mode 100644
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index 0000000..404bcb9
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--- /dev/null
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+++ b/arch/ia64/include/asm/crash-driver.h
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@@ -0,0 +1,90 @@
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+#ifndef _ASM_IA64_CRASH_H
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+#define _ASM_IA64_CRASH_H
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+
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+/*
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+ * linux/include/asm-ia64/crash-driver.h
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+ *
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+ * Copyright (c) 2004 Red Hat, Inc. All rights reserved.
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2, or (at your option)
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+ * any later version.
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+ *
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ *
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+ * You should have received a copy of the GNU General Public License
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+ * along with this program; if not, write to the Free Software
|
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+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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+ *
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+ */
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+
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+#ifdef __KERNEL__
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+
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+#include <linux/efi.h>
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+#include <linux/mm.h>
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+#include <asm/mmzone.h>
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+
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+static inline void *
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+map_virtual(u64 offset, struct page **pp)
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+{
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+ struct page *page;
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+ unsigned long pfn;
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+ u32 type;
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+
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+ if (REGION_NUMBER(offset) == 5) {
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+ char byte;
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+
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+ if (__get_user(byte, (char *)offset) == 0)
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+ return (void *)offset;
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+ else
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+ return NULL;
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+ }
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+
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+ switch (type = efi_mem_type(offset))
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+ {
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+ case EFI_LOADER_CODE:
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+ case EFI_LOADER_DATA:
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+ case EFI_BOOT_SERVICES_CODE:
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+ case EFI_BOOT_SERVICES_DATA:
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+ case EFI_CONVENTIONAL_MEMORY:
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+ break;
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+
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+ default:
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+ printk(KERN_INFO
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+ "crash memory driver: invalid memory type for %lx: %d\n",
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+ offset, type);
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+ return NULL;
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+ }
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+
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+ pfn = offset >> PAGE_SHIFT;
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+
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+ if (!pfn_valid(pfn)) {
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+ printk(KERN_INFO
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+ "crash memory driver: invalid pfn: %lx )\n", pfn);
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+ return NULL;
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+ }
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+
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+ page = pfn_to_page(pfn);
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+
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+ if (!page->virtual) {
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+ printk(KERN_INFO
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+ "crash memory driver: offset: %lx page: %lx page->virtual: NULL\n",
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+ offset, (unsigned long)page);
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+ return NULL;
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+ }
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+
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+ return (page->virtual + (offset & (PAGE_SIZE-1)));
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+}
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+
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+static inline void unmap_virtual(struct page *page)
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+{
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+ return;
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+}
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+
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+#endif /* __KERNEL__ */
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+
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+#endif /* _ASM_IA64_CRASH_H */
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diff --git a/arch/ia64/kernel/ia64_ksyms.c b/arch/ia64/kernel/ia64_ksyms.c
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index d111248..b14b4c6 100644
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--- a/arch/ia64/kernel/ia64_ksyms.c
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+++ b/arch/ia64/kernel/ia64_ksyms.c
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@@ -9,3 +9,6 @@
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EXPORT_SYMBOL(min_low_pfn); /* defined by bootmem.c, but not exported by generic code */
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EXPORT_SYMBOL(max_low_pfn); /* defined by bootmem.c, but not exported by generic code */
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#endif
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+
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+#include <linux/efi.h>
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+EXPORT_SYMBOL_GPL(efi_mem_type);
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diff --git a/arch/powerpc/include/asm/crash-driver.h b/arch/powerpc/include/asm/crash-driver.h
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new file mode 100644
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index 0000000..50092d9
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--- /dev/null
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+++ b/arch/powerpc/include/asm/crash-driver.h
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@@ -0,0 +1,6 @@
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+#ifndef _PPC64_CRASH_H
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+#define _PPC64_CRASH_H
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+
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+#include <asm-generic/crash-driver.h>
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+
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+#endif /* _PPC64_CRASH_H */
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diff --git a/arch/s390/include/asm/crash-driver.h b/arch/s390/include/asm/crash-driver.h
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new file mode 100644
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index 0000000..552be5e
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--- /dev/null
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+++ b/arch/s390/include/asm/crash-driver.h
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@@ -0,0 +1,60 @@
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+#ifndef _S390_CRASH_H
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+#define _S390_CRASH_H
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+
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+#ifdef __KERNEL__
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+
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+#include <linux/mm.h>
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+#include <linux/highmem.h>
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+
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+/*
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+ * For swapped prefix pages get bounce buffer using xlate_dev_mem_ptr()
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+ */
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+static inline void *map_virtual(u64 offset, struct page **pp)
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+{
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+ struct page *page;
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+ unsigned long pfn;
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+ void *vaddr;
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+
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+ vaddr = xlate_dev_mem_ptr(offset);
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+ pfn = ((unsigned long) vaddr) >> PAGE_SHIFT;
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+ if ((unsigned long) vaddr != offset)
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+ page = pfn_to_page(pfn);
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+ else
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+ page = NULL;
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+
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+ if (!page_is_ram(pfn)) {
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+ printk(KERN_INFO
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+ "crash memory driver: !page_is_ram(pfn: %lx)\n", pfn);
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+ return NULL;
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+ }
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+
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+ if (!pfn_valid(pfn)) {
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+ printk(KERN_INFO
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+ "crash memory driver: invalid pfn: %lx )\n", pfn);
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+ return NULL;
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+ }
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+
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+ *pp = page;
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+ return vaddr;
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+}
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+
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+/*
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+ * Free bounce buffer if necessary
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+ */
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+static inline void unmap_virtual(struct page *page)
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+{
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+ void *vaddr;
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+
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+ if (page) {
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+ /*
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+ * Because for bounce buffers vaddr will never be 0
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+ * unxlate_dev_mem_ptr() will always free the bounce buffer.
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+ */
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+ vaddr = (void *)(page_to_pfn(page) << PAGE_SHIFT);
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+ unxlate_dev_mem_ptr(0, vaddr);
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+ }
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+}
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+
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+#endif /* __KERNEL__ */
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+
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+#endif /* _S390_CRASH_H */
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diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
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index 792f9c6..3197995 100644
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--- a/arch/s390/mm/maccess.c
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+++ b/arch/s390/mm/maccess.c
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@@ -201,6 +201,7 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
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put_online_cpus();
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return bounce;
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}
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+EXPORT_SYMBOL_GPL(xlate_dev_mem_ptr);
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|
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/*
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* Free converted buffer for /dev/mem access (if necessary)
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@@ -210,3 +211,4 @@ void unxlate_dev_mem_ptr(phys_addr_t addr, void *buf)
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if ((void *) addr != buf)
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free_page((unsigned long) buf);
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}
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+EXPORT_SYMBOL_GPL(unxlate_dev_mem_ptr);
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diff --git a/arch/x86/include/asm/crash-driver.h b/arch/x86/include/asm/crash-driver.h
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new file mode 100644
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index 0000000..fd4736e
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--- /dev/null
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+++ b/arch/x86/include/asm/crash-driver.h
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@@ -0,0 +1,6 @@
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+#ifndef _X86_CRASH_H
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+#define _X86_CRASH_H
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+
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+#include <asm-generic/crash-driver.h>
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+
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+#endif /* _X86_CRASH_H */
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diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
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index dcc0973..99b99d5 100644
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--- a/drivers/char/Kconfig
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+++ b/drivers/char/Kconfig
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@@ -4,6 +4,9 @@
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menu "Character devices"
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+config CRASH
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+ tristate "Crash Utility memory driver"
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+
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source "drivers/tty/Kconfig"
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config DEVMEM
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diff --git a/drivers/char/Makefile b/drivers/char/Makefile
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index 6e6c244..29cc9c8 100644
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--- a/drivers/char/Makefile
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+++ b/drivers/char/Makefile
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@@ -60,3 +60,5 @@ js-rtc-y = rtc.o
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obj-$(CONFIG_TILE_SROM) += tile-srom.o
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obj-$(CONFIG_XILLYBUS) += xillybus/
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obj-$(CONFIG_POWERNV_OP_PANEL) += powernv-op-panel.o
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+
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+obj-$(CONFIG_CRASH) += crash.o
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diff --git a/drivers/char/crash.c b/drivers/char/crash.c
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new file mode 100644
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index 0000000..085378a
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--- /dev/null
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+++ b/drivers/char/crash.c
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@@ -0,0 +1,128 @@
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+/*
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+ * linux/drivers/char/crash.c
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+ *
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+ * Copyright (C) 2004 Dave Anderson <anderson@redhat.com>
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+ * Copyright (C) 2004 Red Hat, Inc.
|
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+ */
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+
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+/******************************************************************************
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|
+ *
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+ * 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.
|
|
+ *
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|
+ *****************************************************************************/
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|
+
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+#include <linux/module.h>
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+#include <linux/types.h>
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+#include <linux/miscdevice.h>
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+#include <linux/init.h>
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+#include <asm/io.h>
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+#include <asm/uaccess.h>
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+#include <asm/types.h>
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+#include <asm/crash-driver.h>
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+
|
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+#define CRASH_VERSION "1.0"
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+
|
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+/*
|
|
+ * These are the file operation functions that allow crash utility
|
|
+ * access to physical memory.
|
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+ */
|
|
+
|
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+static loff_t
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+crash_llseek(struct file * file, loff_t offset, int orig)
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+{
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+ switch (orig) {
|
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+ case 0:
|
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+ file->f_pos = offset;
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+ return file->f_pos;
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+ case 1:
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+ file->f_pos += offset;
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+ return file->f_pos;
|
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+ default:
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+ return -EINVAL;
|
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+ }
|
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+}
|
|
+
|
|
+/*
|
|
+ * Determine the page address for an address offset value,
|
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+ * get a virtual address for it, and copy it out.
|
|
+ * Accesses must fit within a page.
|
|
+ */
|
|
+static ssize_t
|
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+crash_read(struct file *file, char *buf, size_t count, loff_t *poff)
|
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+{
|
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+ void *vaddr;
|
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+ 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
|
|
|