Author: Yinghai Lu <yinghai@xxxxxxxxxx>
AuthorDate: Sun, 22 Feb 2009 22:14:56 -0800
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Mon, 23 Feb 2009 07:41:31 +0100
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@xxxxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Stefan Reinauer <stepan@xxxxxxxxxxxxxx>
Cc: coreboot@xxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/mpparse.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 7f4d258..37cb1bd 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;
--
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