[PATCH -tip v6 04/22] [BUGFIX] x86: Prohibit probing onnative_set_debugreg/load_idt

[Masami Hiramatsu]

Prohibit probing on native_set_debugreg and native_load_idt.
Since the kprobes uses do_debug for single stepping,
functions called from do_debug before notify_die must not
be probed.
And also native_load_idt is called from paranoid_exit when
returning int3, this also must not be probed.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Cc: Chris Wright <chrisw@xxxxxxxxxxxx>
Cc: Alok Kataria <akataria@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
---
 arch/x86/kernel/paravirt.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 4c785fd..abff75f 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -390,8 +390,10 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
 	.end_context_switch = paravirt_nop,
 };
 
-/* At this point, native_get_debugreg has real function entry */
+/* At this point, native_get/set_debugreg has real function entry */
 NOKPROBE_SYMBOL(native_get_debugreg);
+NOKPROBE_SYMBOL(native_set_debugreg);
+NOKPROBE_SYMBOL(native_load_idt);
 
 struct pv_apic_ops pv_apic_ops = {
 #ifdef CONFIG_X86_LOCAL_APIC


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