The following commit has been merged into the x86/entry branch of tip: Commit-ID: 71ed49d8fb33023f242419a77ecb1141c029cac4 Gitweb: https://git.kernel.org/tip/71ed49d8fb33023f242419a77ecb1141c029cac4 Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Fri, 12 Jun 2020 14:02:27 +02:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Fri, 12 Jun 2020 14:15:48 +02:00 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@xxxxxxxxxx> Debugged-by: Andy Lutomirski <luto@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/CA+G9fYvF3cyrY+-iw_SZtpN-i2qA2BruHg4M=QYECU2-dNdsMw@xxxxxxxxxxxxxx --- arch/x86/include/asm/idtentry.h | 4 ++-- 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 2fc6b0c..cf51c50 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 3a98ff3..2de365f 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;
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