x86: Use find_e820() instead of hard coded trampoline address
Jens found the following crash/regression:
[ 0.000000] found SMP MP-table at [ffff8800000fdd80] fdd80
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 0-fff BIOS data page
and
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 6000-7fff TRAMPOLINE
and bisected it to b24c2a9 ("x86: Move find_smp_config()
earlier and avoid bootmem usage").
It turns out the BIOS is using the first 64k for mptable,
without reserving it.
So try to find good range for the real-mode trampoline instead of
hard coding it, in case some bios tries to use that range for sth.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4B21630A.6000308@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 946a311..f7b8b98 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -73,6 +73,7 @@
#include <asm/mtrr.h>
#include <asm/apic.h>
+#include <asm/trampoline.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
#include <asm/setup.h>
@@ -875,6 +876,13 @@
reserve_brk();
+ /*
+ * Find and reserve possible boot-time SMP configuration:
+ */
+ find_smp_config();
+
+ reserve_trampoline_memory();
+
#ifdef CONFIG_ACPI_SLEEP
/*
* Reserve low memory region for sleep support.
@@ -921,11 +929,6 @@
early_acpi_boot_init();
- /*
- * Find and reserve possible boot-time SMP configuration:
- */
- find_smp_config();
-
#ifdef CONFIG_ACPI_NUMA
/*
* Parse SRAT to discover nodes.