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| author | Vivek Goyal <vgoyal@in.ibm.com> | 2005-06-25 14:58:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-25 16:24:52 -0700 |
| commit | 92aa63a5a1bf2e7b0c79e6716d24b76dbbdcf951 (patch) | |
| tree | 1f4d49c8e9bf02e834e6af8c1f7d4484d9f76c6e /mm/bootmem.c | |
| parent | d58831e4163699de204dea199be2e903bf5d6eff (diff) | |
| download | lwn-92aa63a5a1bf2e7b0c79e6716d24b76dbbdcf951.tar.gz lwn-92aa63a5a1bf2e7b0c79e6716d24b76dbbdcf951.zip | |
[PATCH] kdump: Retrieve saved max pfn
This patch retrieves the max_pfn being used by previous kernel and stores it
in a safe location (saved_max_pfn) before it is overwritten due to user
defined memory map. This pfn is used to make sure that user does not try to
read the physical memory beyond saved_max_pfn.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/bootmem.c')
| -rw-r--r-- | mm/bootmem.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/bootmem.c b/mm/bootmem.c index f82f7aebbee3..45275f1f8947 100644 --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -33,6 +33,14 @@ EXPORT_SYMBOL(max_pfn); /* This is exported so * dma_get_required_mask(), which uses * it, can be an inline function */ +#ifdef CONFIG_CRASH_DUMP +/* + * If we have booted due to a crash, max_pfn will be a very low value. We need + * to know the amount of memory that the previous kernel used. + */ +unsigned long saved_max_pfn; +#endif + /* return the number of _pages_ that will be allocated for the boot bitmap */ unsigned long __init bootmem_bootmap_pages (unsigned long pages) { |