Commit-ID: 55d2d0ad2fb4325f615d1950486fbc5e6fba1769
Gitweb: https://git.kernel.org/tip/55d2d0ad2fb4325f615d1950486fbc5e6fba1769
Author: Chunyu Hu <chuhu@xxxxxxxxxx>
AuthorDate: Mon, 27 Nov 2017 22:21:39 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 28 Nov 2017 08:15:40 +0100
x86/idt: Load idt early in start_secondary
On a secondary, idt is first loaded in cpu_init() with load_current_idt(),
i.e. no exceptions can be handled before that point.
The conversion of WARN() to use UD requires the IDT being loaded earlier as
any warning between start_secondary() and load_curren_idt() in cpu_init()
will result in an unhandled @UD exception and therefore fail the bringup of
the CPU.
Install the IDT handlers right in start_secondary() before calling cpu_init().
[ tglx: Massaged changelog ]
Fixes: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0")
Signed-off-by: Chunyu Hu <chuhu@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: bp@xxxxxxxxx
Cc: rostedt@xxxxxxxxxxx
Cc: luto@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1511792499-4073-1-git-send-email-chuhu@xxxxxxxxxx
---
arch/x86/kernel/smpboot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 3d01df7..05a97d5 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -237,7 +237,7 @@ static void notrace start_secondary(void *unused)
load_cr3(swapper_pg_dir);
__flush_tlb_all();
#endif
-
+ load_current_idt();
cpu_init();
x86_cpuinit.early_percpu_clock_init();
preempt_disable();
--
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