x86/entry/32: Fix #MC and #DB wiring on x86_32
DEFINE_IDTENTRY_MCE and DEFINE_IDTENTRY_DEBUG were wired up as non-RAW
on x86_32, but the code expected them to be RAW.
Get rid of all the macro indirection for them on 32-bit and just use
DECLARE_IDTENTRY_RAW and DEFINE_IDTENTRY_RAW directly.
Also add a warning to make sure that we only hit the _kernel paths
in kernel mode.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/9e90a7ee8e72fd757db6d92e1e5ff16339c1ecf9.1593795633.git.luto@kernel.org
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 94333ac..eeac6dc 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -353,10 +353,6 @@
#else /* CONFIG_X86_64 */
-/* Maps to a regular IDTENTRY on 32bit for now */
-# define DECLARE_IDTENTRY_IST DECLARE_IDTENTRY
-# define DEFINE_IDTENTRY_IST DEFINE_IDTENTRY
-
/**
* DECLARE_IDTENTRY_DF - Declare functions for double fault 32bit variant
* @vector: Vector number (ignored for C)
@@ -387,16 +383,18 @@
#endif /* !CONFIG_X86_64 */
/* C-Code mapping */
+#define DECLARE_IDTENTRY_NMI DECLARE_IDTENTRY_RAW
+#define DEFINE_IDTENTRY_NMI DEFINE_IDTENTRY_RAW
+
+#ifdef CONFIG_X86_64
#define DECLARE_IDTENTRY_MCE DECLARE_IDTENTRY_IST
#define DEFINE_IDTENTRY_MCE DEFINE_IDTENTRY_IST
#define DEFINE_IDTENTRY_MCE_USER DEFINE_IDTENTRY_NOIST
-#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
#define DEFINE_IDTENTRY_DEBUG_USER DEFINE_IDTENTRY_NOIST
+#endif
#else /* !__ASSEMBLY__ */
@@ -443,9 +441,6 @@
# define DECLARE_IDTENTRY_MCE(vector, func) \
DECLARE_IDTENTRY(vector, func)
-# define DECLARE_IDTENTRY_DEBUG(vector, func) \
- DECLARE_IDTENTRY(vector, func)
-
/* No ASM emitted for DF as this goes through a C shim */
# define DECLARE_IDTENTRY_DF(vector, func)
@@ -549,7 +544,11 @@
DECLARE_IDTENTRY_RAW_ERRORCODE(X86_TRAP_PF, exc_page_fault);
#ifdef CONFIG_X86_MCE
+#ifdef CONFIG_X86_64
DECLARE_IDTENTRY_MCE(X86_TRAP_MC, exc_machine_check);
+#else
+DECLARE_IDTENTRY_RAW(X86_TRAP_MC, exc_machine_check);
+#endif
#endif
/* NMI */
@@ -559,7 +558,11 @@
#endif
/* #DB */
+#ifdef CONFIG_X86_64
DECLARE_IDTENTRY_DEBUG(X86_TRAP_DB, exc_debug);
+#else
+DECLARE_IDTENTRY_RAW(X86_TRAP_DB, exc_debug);
+#endif
#ifdef CONFIG_XEN_PV
DECLARE_IDTENTRY_RAW(X86_TRAP_DB, xenpv_exc_debug);
#endif
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index ce9120c..a6a90b5 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1901,6 +1901,8 @@
static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
{
+ WARN_ON_ONCE(user_mode(regs));
+
/*
* Only required when from kernel mode. See
* mce_check_crashing_cpu() for details.
@@ -1954,7 +1956,7 @@
}
#else
/* 32bit unified entry point */
-DEFINE_IDTENTRY_MCE(exc_machine_check)
+DEFINE_IDTENTRY_RAW(exc_machine_check)
{
unsigned long dr7;
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c17f9b5..6ed8cc5 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -925,7 +925,7 @@
}
#else
/* 32 bit does not have separate entry points. */
-DEFINE_IDTENTRY_DEBUG(exc_debug)
+DEFINE_IDTENTRY_RAW(exc_debug)
{
unsigned long dr6, dr7;
