Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- Update the compat layer to allow single-byte watchpoints on all
addresses (similar to the native support)
- arm_pmu: fix the restoration of the counters on the
CPU_PM_ENTER_FAILED path
- Fix build regression with vDSO and Makefile not stripping
CROSS_COMPILE_COMPAT
- Fix the CTR_EL0 (cache type register) sanitisation on heterogeneous
machines (e.g. big.LITTLE)
- Fix the interrupt controller priority mask value when pseudo-NMIs are
enabled
- arm64 kprobes fixes: recovering of the PSTATE.D flag in the
single-step exception handler, NOKPROBE annotations for
unwind_frame() and walk_stackframe(), remove unneeded
rcu_read_lock/unlock from debug handlers
- Several gcc fall-through warnings
- Unused variable warnings
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: Make debug exception handlers visible from RCU
arm64: kprobes: Recover pstate.D in single-step exception handler
arm64/mm: fix variable 'tag' set but not used
arm64/mm: fix variable 'pud' set but not used
arm64: Remove unneeded rcu_read_lock from debug handlers
arm64: unwind: Prohibit probing on return_address()
arm64: Lower priority mask for GIC_PRIO_IRQON
arm64/efi: fix variable 'si' set but not used
arm64: cpufeature: Fix feature comparison for CTR_EL0.{CWG,ERG}
arm64: vdso: Fix Makefile regression
arm64: module: Mark expected switch fall-through
arm64: smp: Mark expected switch fall-through
arm64: hw_breakpoint: Fix warnings about implicit fallthrough
drivers/perf: arm_pmu: Fix failure path in PM notifier
arm64: compat: Allow single-byte watchpoints on all addresses
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index bb1f1db..61de992 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -52,7 +52,7 @@
ifeq ($(CONFIG_CC_IS_CLANG), y)
$(warning CROSS_COMPILE_COMPAT is clang, the compat vDSO will not be built)
- else ifeq ($(CROSS_COMPILE_COMPAT),)
+ else ifeq ($(strip $(CROSS_COMPILE_COMPAT)),)
$(warning CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built)
else ifeq ($(shell which $(CROSS_COMPILE_COMPAT)gcc 2> /dev/null),)
$(error $(CROSS_COMPILE_COMPAT)gcc not found, check CROSS_COMPILE_COMPAT)
diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index 79155a8..89e4c8b 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -155,6 +155,12 @@ static inline void gic_pmr_mask_irqs(void)
BUILD_BUG_ON(GICD_INT_DEF_PRI < (GIC_PRIO_IRQOFF |
GIC_PRIO_PSR_I_SET));
BUILD_BUG_ON(GICD_INT_DEF_PRI >= GIC_PRIO_IRQON);
+ /*
+ * Need to make sure IRQON allows IRQs when SCR_EL3.FIQ is cleared
+ * and non-secure PMR accesses are not subject to the shifts that
+ * are applied to IRQ priorities
+ */
+ BUILD_BUG_ON((0x80 | (GICD_INT_DEF_PRI >> 1)) >= GIC_PRIO_IRQON);
gic_write_pmr(GIC_PRIO_IRQOFF);
}
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 407e2bf..c96ffa4 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -35,9 +35,10 @@
*/
enum ftr_type {
- FTR_EXACT, /* Use a predefined safe value */
- FTR_LOWER_SAFE, /* Smaller value is safe */
- FTR_HIGHER_SAFE,/* Bigger value is safe */
+ FTR_EXACT, /* Use a predefined safe value */
+ FTR_LOWER_SAFE, /* Smaller value is safe */
+ FTR_HIGHER_SAFE, /* Bigger value is safe */
+ FTR_HIGHER_OR_ZERO_SAFE, /* Bigger value is safe, but 0 is biggest */
};
#define FTR_STRICT true /* SANITY check strict matching required */
diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h
index 987926e..063c964 100644
--- a/arch/arm64/include/asm/daifflags.h
+++ b/arch/arm64/include/asm/daifflags.h
@@ -13,6 +13,8 @@
#define DAIF_PROCCTX 0
#define DAIF_PROCCTX_NOIRQ PSR_I_BIT
#define DAIF_ERRCTX (PSR_I_BIT | PSR_A_BIT)
+#define DAIF_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
+
/* mask/save/unmask/restore all exceptions, including interrupts. */
static inline void local_daif_mask(void)
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 8e79ce9..76a1447 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -105,7 +105,11 @@ static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
#define alloc_screen_info(x...) &screen_info
-#define free_screen_info(x...)
+
+static inline void free_screen_info(efi_system_table_t *sys_table_arg,
+ struct screen_info *si)
+{
+}
/* redeclare as 'hidden' so the compiler will generate relative references */
extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index b7ba758..fb04f10 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -210,7 +210,11 @@ extern u64 vabits_user;
#define __tag_reset(addr) untagged_addr(addr)
#define __tag_get(addr) (__u8)((u64)(addr) >> 56)
#else
-#define __tag_set(addr, tag) (addr)
+static inline const void *__tag_set(const void *addr, u8 tag)
+{
+ return addr;
+}
+
#define __tag_reset(addr) (addr)
#define __tag_get(addr) 0
#endif
@@ -301,8 +305,8 @@ static inline void *phys_to_virt(phys_addr_t x)
#define page_to_virt(page) ({ \
unsigned long __addr = \
((__page_to_voff(page)) | PAGE_OFFSET); \
- unsigned long __addr_tag = \
- __tag_set(__addr, page_kasan_tag(page)); \
+ const void *__addr_tag = \
+ __tag_set((void *)__addr, page_kasan_tag(page)); \
((void *)__addr_tag); \
})
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 3f5461f..5fdcfe2 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -447,8 +447,8 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
PMD_TYPE_SECT)
#if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
-#define pud_sect(pud) (0)
-#define pud_table(pud) (1)
+static inline bool pud_sect(pud_t pud) { return false; }
+static inline bool pud_table(pud_t pud) { return true; }
#else
#define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
PUD_TYPE_SECT)
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index b1dd039..1dcf63a 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -30,7 +30,7 @@
* in the the priority mask, it indicates that PSR.I should be set and
* interrupt disabling temporarily does not rely on IRQ priorities.
*/
-#define GIC_PRIO_IRQON 0xc0
+#define GIC_PRIO_IRQON 0xe0
#define GIC_PRIO_IRQOFF (GIC_PRIO_IRQON & ~0x80)
#define GIC_PRIO_PSR_I_SET (1 << 4)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index f29f36a..d19d14b 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -225,8 +225,8 @@ static const struct arm64_ftr_bits ftr_ctr[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
- ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, CTR_CWG_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, CTR_ERG_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
/*
* Linux can handle differing I-cache policies. Userspace JITs will
@@ -468,6 +468,10 @@ static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
case FTR_LOWER_SAFE:
ret = new < cur ? new : cur;
break;
+ case FTR_HIGHER_OR_ZERO_SAFE:
+ if (!cur || !new)
+ break;
+ /* Fallthrough */
case FTR_HIGHER_SAFE:
ret = new > cur ? new : cur;
break;
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index f8719bd..48222a4 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -207,16 +207,16 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr)
list = user_mode(regs) ? &user_step_hook : &kernel_step_hook;
- rcu_read_lock();
-
+ /*
+ * Since single-step exception disables interrupt, this function is
+ * entirely not preemptible, and we can use rcu list safely here.
+ */
list_for_each_entry_rcu(hook, list, node) {
retval = hook->fn(regs, esr);
if (retval == DBG_HOOK_HANDLED)
break;
}
- rcu_read_unlock();
-
return retval;
}
NOKPROBE_SYMBOL(call_step_hook);
@@ -305,14 +305,16 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
list = user_mode(regs) ? &user_break_hook : &kernel_break_hook;
- rcu_read_lock();
+ /*
+ * Since brk exception disables interrupt, this function is
+ * entirely not preemptible, and we can use rcu list safely here.
+ */
list_for_each_entry_rcu(hook, list, node) {
unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
if ((comment & ~hook->mask) == hook->imm)
fn = hook->fn;
}
- rcu_read_unlock();
return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
}
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index dceb845..38ee151 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -536,13 +536,18 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
/* Aligned */
break;
case 1:
- /* Allow single byte watchpoint. */
- if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
- break;
case 2:
/* Allow halfword watchpoints and breakpoints. */
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
break;
+
+ /* Fallthrough */
+ case 3:
+ /* Allow single byte watchpoint. */
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
+ break;
+
+ /* Fallthrough */
default:
return -EINVAL;
}
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 46e643e..03ff15b 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -314,18 +314,21 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
/* MOVW instruction relocations. */
case R_AARCH64_MOVW_UABS_G0_NC:
overflow_check = false;
+ /* Fall through */
case R_AARCH64_MOVW_UABS_G0:
ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 0,
AARCH64_INSN_IMM_MOVKZ);
break;
case R_AARCH64_MOVW_UABS_G1_NC:
overflow_check = false;
+ /* Fall through */
case R_AARCH64_MOVW_UABS_G1:
ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 16,
AARCH64_INSN_IMM_MOVKZ);
break;
case R_AARCH64_MOVW_UABS_G2_NC:
overflow_check = false;
+ /* Fall through */
case R_AARCH64_MOVW_UABS_G2:
ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 32,
AARCH64_INSN_IMM_MOVKZ);
@@ -393,6 +396,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
break;
case R_AARCH64_ADR_PREL_PG_HI21_NC:
overflow_check = false;
+ /* Fall through */
case R_AARCH64_ADR_PREL_PG_HI21:
ovf = reloc_insn_adrp(me, sechdrs, loc, val);
if (ovf && ovf != -ERANGE)
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index bd5dfff..c445282 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -21,6 +21,7 @@
#include <asm/ptrace.h>
#include <asm/cacheflush.h>
#include <asm/debug-monitors.h>
+#include <asm/daifflags.h>
#include <asm/system_misc.h>
#include <asm/insn.h>
#include <linux/uaccess.h>
@@ -168,33 +169,6 @@ static void __kprobes set_current_kprobe(struct kprobe *p)
}
/*
- * When PSTATE.D is set (masked), then software step exceptions can not be
- * generated.
- * SPSR's D bit shows the value of PSTATE.D immediately before the
- * exception was taken. PSTATE.D is set while entering into any exception
- * mode, however software clears it for any normal (none-debug-exception)
- * mode in the exception entry. Therefore, when we are entering into kprobe
- * breakpoint handler from any normal mode then SPSR.D bit is already
- * cleared, however it is set when we are entering from any debug exception
- * mode.
- * Since we always need to generate single step exception after a kprobe
- * breakpoint exception therefore we need to clear it unconditionally, when
- * we become sure that the current breakpoint exception is for kprobe.
- */
-static void __kprobes
-spsr_set_debug_flag(struct pt_regs *regs, int mask)
-{
- unsigned long spsr = regs->pstate;
-
- if (mask)
- spsr |= PSR_D_BIT;
- else
- spsr &= ~PSR_D_BIT;
-
- regs->pstate = spsr;
-}
-
-/*
* Interrupts need to be disabled before single-step mode is set, and not
* reenabled until after single-step mode ends.
* Without disabling interrupt on local CPU, there is a chance of
@@ -205,17 +179,17 @@ spsr_set_debug_flag(struct pt_regs *regs, int mask)
static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb,
struct pt_regs *regs)
{
- kcb->saved_irqflag = regs->pstate;
+ kcb->saved_irqflag = regs->pstate & DAIF_MASK;
regs->pstate |= PSR_I_BIT;
+ /* Unmask PSTATE.D for enabling software step exceptions. */
+ regs->pstate &= ~PSR_D_BIT;
}
static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb,
struct pt_regs *regs)
{
- if (kcb->saved_irqflag & PSR_I_BIT)
- regs->pstate |= PSR_I_BIT;
- else
- regs->pstate &= ~PSR_I_BIT;
+ regs->pstate &= ~DAIF_MASK;
+ regs->pstate |= kcb->saved_irqflag;
}
static void __kprobes
@@ -252,8 +226,6 @@ static void __kprobes setup_singlestep(struct kprobe *p,
set_ss_context(kcb, slot); /* mark pending ss */
- spsr_set_debug_flag(regs, 0);
-
/* IRQs and single stepping do not mix well. */
kprobes_save_local_irqflag(kcb, regs);
kernel_enable_single_step(regs);
diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index c4ae647..a5e8b3b 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -8,6 +8,7 @@
#include <linux/export.h>
#include <linux/ftrace.h>
+#include <linux/kprobes.h>
#include <asm/stack_pointer.h>
#include <asm/stacktrace.h>
@@ -29,6 +30,7 @@ static int save_return_addr(struct stackframe *frame, void *d)
return 0;
}
}
+NOKPROBE_SYMBOL(save_return_addr);
void *return_address(unsigned int level)
{
@@ -49,3 +51,4 @@ void *return_address(unsigned int level)
return NULL;
}
EXPORT_SYMBOL_GPL(return_address);
+NOKPROBE_SYMBOL(return_address);
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index ea90d3b..018a33e 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -152,8 +152,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
pr_crit("CPU%u: died during early boot\n", cpu);
break;
}
- /* Fall through */
pr_crit("CPU%u: may not have shut down cleanly\n", cpu);
+ /* Fall through */
case CPU_STUCK_IN_KERNEL:
pr_crit("CPU%u: is stuck in kernel\n", cpu);
if (status & CPU_STUCK_REASON_52_BIT_VA)
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 2b160ae5..a336cb1 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -7,6 +7,7 @@
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/ftrace.h>
+#include <linux/kprobes.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
@@ -111,6 +112,7 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
return 0;
}
+NOKPROBE_SYMBOL(unwind_frame);
void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data)
@@ -125,6 +127,7 @@ void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
break;
}
}
+NOKPROBE_SYMBOL(walk_stackframe);
#ifdef CONFIG_STACKTRACE
struct stack_trace_data {
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 9568c11..cfd65b6 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -777,6 +777,53 @@ void __init hook_debug_fault_code(int nr,
debug_fault_info[nr].name = name;
}
+/*
+ * In debug exception context, we explicitly disable preemption despite
+ * having interrupts disabled.
+ * This serves two purposes: it makes it much less likely that we would
+ * accidentally schedule in exception context and it will force a warning
+ * if we somehow manage to schedule by accident.
+ */
+static void debug_exception_enter(struct pt_regs *regs)
+{
+ /*
+ * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
+ * already disabled to preserve the last enabled/disabled addresses.
+ */
+ if (interrupts_enabled(regs))
+ trace_hardirqs_off();
+
+ if (user_mode(regs)) {
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
+ } else {
+ /*
+ * We might have interrupted pretty much anything. In
+ * fact, if we're a debug exception, we can even interrupt
+ * NMI processing. We don't want this code makes in_nmi()
+ * to return true, but we need to notify RCU.
+ */
+ rcu_nmi_enter();
+ }
+
+ preempt_disable();
+
+ /* This code is a bit fragile. Test it. */
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "exception_enter didn't work");
+}
+NOKPROBE_SYMBOL(debug_exception_enter);
+
+static void debug_exception_exit(struct pt_regs *regs)
+{
+ preempt_enable_no_resched();
+
+ if (!user_mode(regs))
+ rcu_nmi_exit();
+
+ if (interrupts_enabled(regs))
+ trace_hardirqs_on();
+}
+NOKPROBE_SYMBOL(debug_exception_exit);
+
#ifdef CONFIG_ARM64_ERRATUM_1463225
DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
@@ -817,12 +864,7 @@ asmlinkage void __exception do_debug_exception(unsigned long addr_if_watchpoint,
if (cortex_a76_erratum_1463225_debug_handler(regs))
return;
- /*
- * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
- * already disabled to preserve the last enabled/disabled addresses.
- */
- if (interrupts_enabled(regs))
- trace_hardirqs_off();
+ debug_exception_enter(regs);
if (user_mode(regs) && !is_ttbr0_addr(pc))
arm64_apply_bp_hardening();
@@ -832,7 +874,6 @@ asmlinkage void __exception do_debug_exception(unsigned long addr_if_watchpoint,
inf->sig, inf->code, (void __user *)pc, esr);
}
- if (interrupts_enabled(regs))
- trace_hardirqs_on();
+ debug_exception_exit(regs);
}
NOKPROBE_SYMBOL(do_debug_exception);
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 2d06b80..df352b3 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -723,8 +723,8 @@ static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
cpu_pm_pmu_setup(armpmu, cmd);
break;
case CPU_PM_EXIT:
- cpu_pm_pmu_setup(armpmu, cmd);
case CPU_PM_ENTER_FAILED:
+ cpu_pm_pmu_setup(armpmu, cmd);
armpmu->start(armpmu);
break;
default: