Messages in this thread Patch in this message | | | From | "Eric W. Biederman" <> | Subject | [PATCH 27/29] crashdump-routines-for-copying-dump-pages | Date | Wed, 19 Jan 2005 0:31:37 -0700 |
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kernel/crash.c has been renamed kernel/crash_dump.c to clarify it's purpose.
From: Hariprasad Nellitheertha <hari@in.ibm.com>
This patch provides the interfaces necessary to read the dump contents, treating it as a high memory device.
Signed off by Hariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: Eric Biederman <ebiederm@xmission.com> ---
arch/i386/mm/highmem.c | 18 ++++++++++++++++++ include/asm-i386/highmem.h | 1 + include/linux/highmem.h | 1 + kernel/crash_dump.c | 33 +++++++++++++++++++++++++++++++++ 4 files changed, 53 insertions(+)
diff -uNr linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/arch/i386/mm/highmem.c linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/arch/i386/mm/highmem.c --- linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/arch/i386/mm/highmem.c Fri Jan 14 04:32:22 2005 +++ linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/arch/i386/mm/highmem.c Tue Jan 18 23:16:41 2005 @@ -74,6 +74,24 @@ preempt_check_resched(); } +/* This is the same as kmap_atomic() but can map memory that doesn't + * have a struct page associated with it. + */ +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + inc_preempt_count(); + + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot)); + __flush_tlb_one(vaddr); + + return (void*) vaddr; +} + struct page *kmap_atomic_to_page(char *ptr) { unsigned long idx, vaddr = (unsigned long)ptr; diff -uNr linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/include/asm-i386/highmem.h linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/include/asm-i386/highmem.h --- linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/include/asm-i386/highmem.h Fri Jan 14 04:32:27 2005 +++ linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/include/asm-i386/highmem.h Tue Jan 18 23:16:41 2005 @@ -72,6 +72,7 @@ void kunmap(struct page *page); char *kmap_atomic(struct page *page, enum km_type type); void kunmap_atomic(char *kvaddr, enum km_type type); +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); struct page *kmap_atomic_to_page(char *ptr); #define flush_cache_kmaps() do { } while (0) diff -uNr linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/include/linux/highmem.h linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/include/linux/highmem.h --- linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/include/linux/highmem.h Fri Jan 14 04:32:27 2005 +++ linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/include/linux/highmem.h Tue Jan 18 23:16:41 2005 @@ -28,6 +28,7 @@ #define kmap_atomic(page, idx) ((char *)page_address(page)) #define kunmap_atomic(addr, idx) do { char *p = addr; (void)p; } while (0) +#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) #define kmap_atomic_to_page(ptr) virt_to_page(ptr) #endif /* CONFIG_HIGHMEM */ diff -uNr linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/kernel/crash_dump.c linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/kernel/crash_dump.c --- linux-2.6.11-rc1-mm1-nokexec-crashdump-memory-preserving-reboot-using-kexec/kernel/crash_dump.c Tue Jan 18 23:16:24 2005 +++ linux-2.6.11-rc1-mm1-nokexec-crashdump-routines-for-copying-dump-pages/kernel/crash_dump.c Tue Jan 18 23:16:41 2005 @@ -8,6 +8,39 @@ #include <linux/smp_lock.h> #include <linux/errno.h> #include <linux/proc_fs.h> +#include <linux/bootmem.h> +#include <linux/highmem.h> +#include <linux/crash_dump.h> + #include <asm/io.h> #include <asm/uaccess.h> +/* + * Copy a page from "oldmem". For this page, there is no pte mapped + * in the current kernel. We stitch up a pte, similar to kmap_atomic. + */ +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, + size_t csize, int userbuf) +{ + void *page, *vaddr; + + if (!csize) + return 0; + + page = kmalloc(PAGE_SIZE, GFP_KERNEL); + + vaddr = kmap_atomic_pfn(pfn, KM_PTE0); + copy_page(page, vaddr); + kunmap_atomic(vaddr, KM_PTE0); + + if (userbuf) { + if (copy_to_user(buf, page, csize)) { + kfree(page); + return -EFAULT; + } + } else + memcpy(buf, page, csize); + kfree(page); + + return 0; +} - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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