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authorThomas Gleixner <tglx@linutronix.de>2020-06-12 15:02:27 +0300
committerThomas Gleixner <tglx@linutronix.de>2020-06-12 15:15:48 +0300
commit71ed49d8fb33023f242419a77ecb1141c029cac4 (patch)
treea743da99e822b09ab03ba67561603c1077fac484
parent15a416e8aaa758b5534f64a3972dae05275bc225 (diff)
downloadlinux-71ed49d8fb33023f242419a77ecb1141c029cac4.tar.xz
x86/entry: Make NMI use IDTENTRY_RAW
For no reason other than beginning brainmelt, IDTENTRY_NMI was mapped to IDTENTRY_IST. This is not a problem on 64bit because the IST default entry point maps to IDTENTRY_RAW which does not any entry handling. The surplus function declaration for the noist C entry point is unused and as there is no ASM code emitted for NMI this went unnoticed. On 32bit IDTENTRY_IST maps to a regular IDTENTRY which does the normal entry handling. That is clearly the wrong thing to do for NMI. Map it to IDTENTRY_RAW to unbreak it. The IDTENTRY_NMI mapping needs to stay to avoid emitting ASM code. Fixes: 6271fef00b34 ("x86/entry: Convert NMI to IDTENTRY_NMI") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Debugged-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/CA+G9fYvF3cyrY+-iw_SZtpN-i2qA2BruHg4M=QYECU2-dNdsMw@mail.gmail.com
-rw-r--r--arch/x86/include/asm/idtentry.h4
-rw-r--r--arch/x86/kernel/nmi.c2
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 2fc6b0c58341..cf51c50eb356 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -391,8 +391,8 @@ __visible noinstr void func(struct pt_regs *regs, \
#define DEFINE_IDTENTRY_MCE DEFINE_IDTENTRY_IST
#define DEFINE_IDTENTRY_MCE_USER DEFINE_IDTENTRY_NOIST
-#define DECLARE_IDTENTRY_NMI DECLARE_IDTENTRY_IST
-#define DEFINE_IDTENTRY_NMI DEFINE_IDTENTRY_IST
+#define DECLARE_IDTENTRY_NMI DECLARE_IDTENTRY_RAW
+#define DEFINE_IDTENTRY_NMI DEFINE_IDTENTRY_RAW
#define DECLARE_IDTENTRY_DEBUG DECLARE_IDTENTRY_IST
#define DEFINE_IDTENTRY_DEBUG DEFINE_IDTENTRY_IST
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 3a98ff36f411..2de365f15684 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -476,7 +476,7 @@ static DEFINE_PER_CPU(enum nmi_states, nmi_state);
static DEFINE_PER_CPU(unsigned long, nmi_cr2);
static DEFINE_PER_CPU(unsigned long, nmi_dr7);
-DEFINE_IDTENTRY_NMI(exc_nmi)
+DEFINE_IDTENTRY_RAW(exc_nmi)
{
if (IS_ENABLED(CONFIG_SMP) && cpu_is_offline(smp_processor_id()))
return;