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authorYinghai Lu <yinghai@kernel.org>2009-02-22 22:14:56 -0800
committerIngo Molnar <mingo@elte.hu>2009-02-23 07:41:31 +0100
commitecda06289f8202d4c6beb235f59ea464f4a91209 (patch)
tree351d1919e4ea31dc727b6793bab2527461d06ef5 /arch/x86/kernel/mpparse.c
parent8e6dafd6c741cd4679b4de3c5d9698851e4fa59c (diff)
x86: check mptable physptr with max_low_pfn on 32bit
Impact: fix early crash on LinuxBIOS systems Kevin O'Connor reported that Coreboot aka LinuxBIOS tries to put mptable somewhere very high, well above max_low_pfn (below which BIOSes generally put the mptable), causing a panic. The BIOS will probably be changed to be compatible with older Linus versions, but nevertheless the MP-spec does not forbid an MP-table in arbitrary system RAM, so make sure it all works even if the table is in an unexpected place. Check physptr with max_low_pfn * PAGE_SIZE. Reported-by: Kevin O'Connor <kevin@koconnor.net> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Stefan Reinauer <stepan@coresystems.de> Cc: coreboot@coreboot.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/mpparse.c')
-rw-r--r--arch/x86/kernel/mpparse.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 7f4d2586972e..37cb1bda1baf 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -710,13 +710,22 @@ static int __init smp_scan_config(unsigned long base, unsigned long length,
* of physical memory; so that simply reserving
* PAGE_SIZE from mpf->physptr yields BUG()
* in reserve_bootmem.
+ * also need to make sure physptr is below than
+ * max_low_pfn
+ * we don't need reserve the area above max_low_pfn
*/
unsigned long end = max_low_pfn * PAGE_SIZE;
- if (mpf->physptr + size > end)
- size = end - mpf->physptr;
-#endif
+
+ if (mpf->physptr < end) {
+ if (mpf->physptr + size > end)
+ size = end - mpf->physptr;
+ reserve_bootmem_generic(mpf->physptr, size,
+ BOOTMEM_DEFAULT);
+ }
+#else
reserve_bootmem_generic(mpf->physptr, size,
BOOTMEM_DEFAULT);
+#endif
}
return 1;