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Code Issues Releases Wiki Activity

x86/entry/32: Fix #MC and #DB wiring on x86_32

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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
This commit is contained in:
Andy Lutomirski 2020-07-03 10:02:56 -07:00 committed by Thomas Gleixner
parent f41f082422
commit 13cbc0cd4a
3 changed files with 17 additions and 12 deletions
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23
arch/x86/include/asm/idtentry.h
View file

@ -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

4
arch/x86/kernel/cpu/mce/core.c
View file

@ -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;

2
arch/x86/kernel/traps.c
View file

@ -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;