[Xen-devel] [PATCH 1/4] x86/wakeup/sleep: Check whether the TSS GDT descriptor is empty before using it.

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

We check the TSS descriptor before we try to dereference it.
Also fix up the value to use the #defines.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 arch/x86/power/cpu.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 218cdb1..c17370e 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -133,7 +133,9 @@ static void fix_processor_context(void)
 {
        int cpu = smp_processor_id();
        struct tss_struct *t = &per_cpu(init_tss, cpu);
-
+#ifdef CONFIG_X86_64
+       struct desc_struct *desc = get_cpu_gdt_table(cpu);
+#endif
        set_tss_desc(cpu, t);   /*
                                 * This just modifies memory; should not be
                                 * necessary. But... This is necessary, because
@@ -142,7 +144,8 @@ static void fix_processor_context(void)
                                 */
 
 #ifdef CONFIG_X86_64
-       get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS].type = 9;
+       if (!desc_empty(&desc[GDT_ENTRY_TSS]))
+               desc[GDT_ENTRY_TSS].type = DESC_TSS;
 
        syscall_init();                         /* This sets MSR_*STAR and 
related */
 #endif
-- 
1.7.7.6


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