Displaying 2 results from an estimated 2 matches for "__nmi_exit".
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__gi_exit
2020 Jun 23
2
Should SEV-ES #VC use IST? (Re: [PATCH] Allow RDTSC and RDTSCP from userspace)
...iles changed, 18 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index af0d57ed5e69..e38e4f34c90c 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -742,6 +742,13 @@ noinstr void idtentry_exit_nmi(struct pt_regs *regs, bool restore)
__nmi_exit();
}
+noinstr void idtentry_validate_ist(struct pt_regs *regs)
+{
+ if ((regs->sp & ~(EXCEPTION_STKSZ-1)) ==
+ (_RET_IP_ & ~(EXCEPTION_STKSZ-1)))
+ die("IST stack recursion", regs, 0);
+}
+
#ifdef CONFIG_XEN_PV
#ifndef CONFIG_PREEMPTION
/*
diff --git a/arch/x86/inclu...
2020 Jun 23
2
Should SEV-ES #VC use IST? (Re: [PATCH] Allow RDTSC and RDTSCP from userspace)
On Tue, Jun 23, 2020 at 02:52:01PM +0200, Peter Zijlstra wrote:
> On Tue, Jun 23, 2020 at 02:04:33PM +0200, Joerg Roedel wrote:
> > No, the recursion check is fine, because overwriting an already used IST
> > stack doesn't matter (as long as it can be detected) if we are going to
> > panic anyway. It doesn't matter because the kernel will not leave the
> >