[PATCH v7u1 03/31] x86, realmode: set real_mode permissions early

From: Yinghai Lu
Date: Thu Jan 03 2013 - 19:49:31 EST


Trampoline code is executed by APs with kernel low mapping.
We need to set trampoline code to EXEC early before we do smp
AP bootings.

Found the problem after switching to #PF handler set page table,
and we do not set initial kernel low mapping with EXEC anymore in
arch/x86/kernel/head_64.S.

Change to use early_initcall instead that will make sure tramopline
will have EXEC set.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/realmode/init.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 8045026..b96fe6f 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -111,5 +111,9 @@ static int __init set_real_mode_permissions(void)

return 0;
}
-
-arch_initcall(set_real_mode_permissions);
+/*
+ * Trampoline will be executed by APs with SMP.
+ * So we need to set it to EXEC in do_pre_smp_initcalls() at least,
+ * and that needs early_initcall().
+ */
+early_initcall(set_real_mode_permissions);
--
1.7.10.4

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