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| author | Yinghai Lu <yinghai@kernel.org> | 2009-12-10 21:07:22 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-12-11 08:28:22 (GMT) |
| commit | 893f38d144a4d96d2483cd7c3801d26e1b2c23e9 (patch) | |
| tree | a21107699f5b9938db07697ed2b0ff3c725bf266 /arch/x86/kernel/trampoline.c | |
| parent | ebb682f522411abbe358059a256a8672ec0bd55b (diff) | |
| download | linux-893f38d144a4d96d2483cd7c3801d26e1b2c23e9.tar.xz | |
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>
Diffstat (limited to 'arch/x86/kernel/trampoline.c')
| -rw-r--r-- | arch/x86/kernel/trampoline.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kernel/trampoline.c b/arch/x86/kernel/trampoline.c index cd02212..c652ef6 100644 --- a/arch/x86/kernel/trampoline.c +++ b/arch/x86/kernel/trampoline.c @@ -12,21 +12,19 @@ #endif /* ready for x86_64 and x86 */ -unsigned char *__trampinitdata trampoline_base = __va(TRAMPOLINE_BASE); +unsigned char *__trampinitdata trampoline_base; void __init reserve_trampoline_memory(void) { -#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) - */ - reserve_early(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE"); -#endif + unsigned long mem; + /* Has to be in very low memory so we can execute real-mode AP code. */ - reserve_early(TRAMPOLINE_BASE, TRAMPOLINE_BASE + TRAMPOLINE_SIZE, - "TRAMPOLINE"); + mem = find_e820_area(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE); + if (mem == -1L) + panic("Cannot allocate trampoline\n"); + + trampoline_base = __va(mem); + reserve_early(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE"); } /* |