diff options
| -rw-r--r-- | arch/x86/include/asm/idtentry.h | 24 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 12 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 28 | ||||
| -rw-r--r-- | arch/x86/xen/xen-asm_64.S | 5 |
4 files changed, 44 insertions, 25 deletions
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h index cf51c50eb356..94333ac3092b 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -398,18 +398,6 @@ __visible noinstr void func(struct pt_regs *regs, \ #define DEFINE_IDTENTRY_DEBUG DEFINE_IDTENTRY_IST #define DEFINE_IDTENTRY_DEBUG_USER DEFINE_IDTENTRY_NOIST -/** - * DECLARE_IDTENTRY_XEN - Declare functions for XEN redirect IDT entry points - * @vector: Vector number (ignored for C) - * @func: Function name of the entry point - * - * Used for xennmi and xendebug redirections. No DEFINE as this is all ASM - * indirection magic. - */ -#define DECLARE_IDTENTRY_XEN(vector, func) \ - asmlinkage void xen_asm_exc_xen##func(void); \ - asmlinkage void asm_exc_xen##func(void) - #else /* !__ASSEMBLY__ */ /* @@ -469,10 +457,6 @@ __visible noinstr void func(struct pt_regs *regs, \ /* No ASM code emitted for NMI */ #define DECLARE_IDTENTRY_NMI(vector, func) -/* XEN NMI and DB wrapper */ -#define DECLARE_IDTENTRY_XEN(vector, func) \ - idtentry vector asm_exc_xen##func exc_##func has_error_code=0 - /* * ASM code to emit the common vector entry stubs where each stub is * packed into 8 bytes. @@ -570,11 +554,15 @@ DECLARE_IDTENTRY_MCE(X86_TRAP_MC, exc_machine_check); /* NMI */ DECLARE_IDTENTRY_NMI(X86_TRAP_NMI, exc_nmi); -DECLARE_IDTENTRY_XEN(X86_TRAP_NMI, nmi); +#ifdef CONFIG_XEN_PV +DECLARE_IDTENTRY_RAW(X86_TRAP_NMI, xenpv_exc_nmi); +#endif /* #DB */ DECLARE_IDTENTRY_DEBUG(X86_TRAP_DB, exc_debug); -DECLARE_IDTENTRY_XEN(X86_TRAP_DB, debug); +#ifdef CONFIG_XEN_PV +DECLARE_IDTENTRY_RAW(X86_TRAP_DB, xenpv_exc_debug); +#endif /* #DF */ DECLARE_IDTENTRY_DF(X86_TRAP_DF, exc_double_fault); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index f9727b96961f..c17f9b57171f 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -866,6 +866,12 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs, trace_hardirqs_off_finish(); /* + * If something gets miswired and we end up here for a user mode + * #DB, we will malfunction. + */ + WARN_ON_ONCE(user_mode(regs)); + + /* * Catch SYSENTER with TF set and clear DR_STEP. If this hit a * watchpoint at the same time then that will still be handled. */ @@ -883,6 +889,12 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs, static __always_inline void exc_debug_user(struct pt_regs *regs, unsigned long dr6) { + /* + * If something gets miswired and we end up here for a kernel mode + * #DB, we will malfunction. + */ + WARN_ON_ONCE(!user_mode(regs)); + idtentry_enter_user(regs); instrumentation_begin(); diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index acc49fa6a097..0d68948c82ad 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -598,6 +598,26 @@ static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum, } #ifdef CONFIG_X86_64 +void noist_exc_debug(struct pt_regs *regs); + +DEFINE_IDTENTRY_RAW(xenpv_exc_nmi) +{ + /* On Xen PV, NMI doesn't use IST. The C part is the sane as native. */ + exc_nmi(regs); +} + +DEFINE_IDTENTRY_RAW(xenpv_exc_debug) +{ + /* + * There's no IST on Xen PV, but we still need to dispatch + * to the correct handler. + */ + if (user_mode(regs)) + noist_exc_debug(regs); + else + exc_debug(regs); +} + struct trap_array_entry { void (*orig)(void); void (*xen)(void); @@ -609,18 +629,18 @@ struct trap_array_entry { .xen = xen_asm_##func, \ .ist_okay = ist_ok } -#define TRAP_ENTRY_REDIR(func, xenfunc, ist_ok) { \ +#define TRAP_ENTRY_REDIR(func, ist_ok) { \ .orig = asm_##func, \ - .xen = xen_asm_##xenfunc, \ + .xen = xen_asm_xenpv_##func, \ .ist_okay = ist_ok } static struct trap_array_entry trap_array[] = { - TRAP_ENTRY_REDIR(exc_debug, exc_xendebug, true ), + TRAP_ENTRY_REDIR(exc_debug, true ), TRAP_ENTRY(exc_double_fault, true ), #ifdef CONFIG_X86_MCE TRAP_ENTRY(exc_machine_check, true ), #endif - TRAP_ENTRY_REDIR(exc_nmi, exc_xennmi, true ), + TRAP_ENTRY_REDIR(exc_nmi, true ), TRAP_ENTRY(exc_int3, false ), TRAP_ENTRY(exc_overflow, false ), #ifdef CONFIG_IA32_EMULATION diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S index e1e1c7eafa60..aab1d99b2b48 100644 --- a/arch/x86/xen/xen-asm_64.S +++ b/arch/x86/xen/xen-asm_64.S @@ -29,10 +29,9 @@ _ASM_NOKPROBE(xen_\name) .endm xen_pv_trap asm_exc_divide_error -xen_pv_trap asm_exc_debug -xen_pv_trap asm_exc_xendebug +xen_pv_trap asm_xenpv_exc_debug xen_pv_trap asm_exc_int3 -xen_pv_trap asm_exc_xennmi +xen_pv_trap asm_xenpv_exc_nmi xen_pv_trap asm_exc_overflow xen_pv_trap asm_exc_bounds xen_pv_trap asm_exc_invalid_op |