Commit 13cbc0cd authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Thomas Gleixner
Browse files

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: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/9e90a7ee8e72fd757db6d92e1e5ff16339c1ecf9.1593795633.git.luto@kernel.org
parent f41f0824

arch/x86/include/asm/idtentry.h

+13 −10
Original line number Diff line number Diff line
@@ -353,10 +353,6 @@ static __always_inline void __##func(struct pt_regs *regs) 


#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 @@ __visible noinstr void func(struct pt_regs *regs, \ 
#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 @@ __visible noinstr void func(struct pt_regs *regs, \ 
# 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(X86_TRAP_BP, exc_int3); 
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 @@ DECLARE_IDTENTRY_RAW(X86_TRAP_NMI, xenpv_exc_nmi); 
#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

arch/x86/kernel/cpu/mce/core.c

+3 −1
Original line number Diff line number Diff line
@@ -1901,6 +1901,8 @@ void (*machine_check_vector)(struct pt_regs *) = unexpected_machine_check; 


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 @@ DEFINE_IDTENTRY_MCE_USER(exc_machine_check) 
}

#else

/* 32bit unified entry point */

DEFINE_IDTENTRY_MCE(exc_machine_check)

DEFINE_IDTENTRY_RAW(exc_machine_check)

{

	unsigned long dr7;

arch/x86/kernel/traps.c

+1 −1
Original line number Diff line number Diff line
@@ -925,7 +925,7 @@ DEFINE_IDTENTRY_DEBUG_USER(exc_debug) 
}

#else

/* 32 bit does not have separate entry points. */

DEFINE_IDTENTRY_DEBUG(exc_debug)

DEFINE_IDTENTRY_RAW(exc_debug)

{

	unsigned long dr6, dr7;

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