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x86: Use find_e820() instead of hard coded trampoline address

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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>
This commit is contained in:
Yinghai Lu
2009-12-10 13:07:22 -08:00
committed by Ingo Molnar
parent ebb682f522
commit 893f38d144
7 changed files with 27 additions and 25 deletions
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11
arch/x86/kernel/e820.c
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@ -732,7 +732,16 @@ struct early_res {
char overlap_ok;
};
static struct early_res early_res[MAX_EARLY_RES] __initdata = {
{ 0, PAGE_SIZE, "BIOS data page" }, /* BIOS data page */
{ 0, PAGE_SIZE, "BIOS data page", 1 }, /* BIOS data page */
#ifdef CONFIG_X86_32
/*
* But first pinch a few for the stack/trampoline stuff
* FIXME: Don't need the extra page at 4K, but need to fix
* trampoline before removing it. (see the GDT stuff)
*/
{ PAGE_SIZE, PAGE_SIZE, "EX TRAMPOLINE", 1 },
#endif
{}
};