diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-06-12 14:02:27 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-12 14:15:48 +0200 |
| commit | 71ed49d8fb33023f242419a77ecb1141c029cac4 (patch) | |
| tree | a743da99e822b09ab03ba67561603c1077fac484 | |
| parent | x86/entry: Treat BUG/WARN as NMI-like entries (diff) | |
| download | linux-71ed49d8fb33023f242419a77ecb1141c029cac4.tar.xz linux-71ed49d8fb33023f242419a77ecb1141c029cac4.zip | |
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.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/nmi.c | 2 |
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; |