Messages in this thread Patch in this message |  | | Date | Mon, 27 Nov 2017 23:22:14 -0800 | From | tip-bot for Chunyu Hu <> | Subject | [tip:x86/urgent] x86/idt: Load idt early in start_secondary |
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Commit-ID: 55d2d0ad2fb4325f615d1950486fbc5e6fba1769 Gitweb: https://git.kernel.org/tip/55d2d0ad2fb4325f615d1950486fbc5e6fba1769 Author: Chunyu Hu <chuhu@redhat.com> AuthorDate: Mon, 27 Nov 2017 22:21:39 +0800 Committer: Thomas Gleixner <tglx@linutronix.de> 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@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: rostedt@goodmis.org Cc: luto@kernel.org Link: https://lkml.kernel.org/r/1511792499-4073-1-git-send-email-chuhu@redhat.com --- 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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