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authorYinghai Lu <yinghai@kernel.org>2009-12-10 16:07:22 -0500
committerIngo Molnar <mingo@elte.hu>2009-12-11 03:28:22 -0500
commit893f38d144a4d96d2483cd7c3801d26e1b2c23e9 (patch)
treea21107699f5b9938db07697ed2b0ff3c725bf266 /arch/x86/kernel/trampoline.c
parentebb682f522411abbe358059a256a8672ec0bd55b (diff)
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.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kernel/trampoline.c b/arch/x86/kernel/trampoline.c
index cd022121cab6..c652ef62742d 100644
--- a/arch/x86/kernel/trampoline.c
+++ b/arch/x86/kernel/trampoline.c
@@ -12,21 +12,19 @@
12#endif 12#endif
13 13
14/* ready for x86_64 and x86 */ 14/* ready for x86_64 and x86 */
15unsigned char *__trampinitdata trampoline_base = __va(TRAMPOLINE_BASE); 15unsigned char *__trampinitdata trampoline_base;
16 16
17void __init reserve_trampoline_memory(void) 17void __init reserve_trampoline_memory(void)
18{ 18{
19#ifdef CONFIG_X86_32 19 unsigned long mem;
20 /* 20
21 * But first pinch a few for the stack/trampoline stuff
22 * FIXME: Don't need the extra page at 4K, but need to fix
23 * trampoline before removing it. (see the GDT stuff)
24 */
25 reserve_early(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE");
26#endif
27 /* Has to be in very low memory so we can execute real-mode AP code. */ 21 /* Has to be in very low memory so we can execute real-mode AP code. */
28 reserve_early(TRAMPOLINE_BASE, TRAMPOLINE_BASE + TRAMPOLINE_SIZE, 22 mem = find_e820_area(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE);
29 "TRAMPOLINE"); 23 if (mem == -1L)
24 panic("Cannot allocate trampoline\n");
25
26 trampoline_base = __va(mem);
27 reserve_early(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE");
30} 28}
31 29
32/* 30/*