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| author | Bob Picco <bob.picco@hp.com> | 2007-06-07 21:01:35 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-08-04 09:10:23 -0700 |
| commit | b6b364eaa2ec37e9d1108fcbf4a025a3a407b879 (patch) | |
| tree | fd4df397b185ab881c75479ad2f60bb00d13a00b | |
| parent | 50099883039e51de64f84938a3db114b4c0cb12f (diff) | |
| download | linux-stable-b6b364eaa2ec37e9d1108fcbf4a025a3a407b879.tar.gz linux-stable-b6b364eaa2ec37e9d1108fcbf4a025a3a407b879.tar.bz2 linux-stable-b6b364eaa2ec37e9d1108fcbf4a025a3a407b879.zip | |
sparsemem: fix oops in x86_64 show_mem
We aren't sampling for holes in memory. Thus we encounter a section hole with
empty section map pointer for SPARSEMEM and OOPs for show_mem. This issue
has been seen in 2.6.21, current git and current mm. This patch is for
2.6.21 stable. It was tested against sparsemem.
Previous to commit f0a5a58aa812b31fd9f197c4ba48245942364eae memory_present
was called for node_start_pfn to node_end_pfn. This would cover the hole(s)
with reserved pages and valid sections. Most SPARSEMEM supported arches
do a pfn_valid check in show_mem before computing the page structure address.
This issue was brought to my attention on IRC by Arnaldo Carvalho de Melo at
acme@redhat.com. Thanks to Arnaldo for testing.
Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86_64/mm/init.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c index 6fd126a464f5..df35d6d83fa7 100644 --- a/arch/x86_64/mm/init.c +++ b/arch/x86_64/mm/init.c @@ -72,6 +72,8 @@ void show_mem(void) for_each_online_pgdat(pgdat) { for (i = 0; i < pgdat->node_spanned_pages; ++i) { + if (!pfn_valid(pgdat->node_start_pfn + i)) + continue; page = pfn_to_page(pgdat->node_start_pfn + i); total++; if (PageReserved(page)) |