diff --git a/arch/Kconfig b/arch/Kconfig index f06010fb4838..acda512da2e2 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -137,6 +137,17 @@ config HAVE_HW_BREAKPOINT bool depends on PERF_EVENTS +config HAVE_MIXED_BREAKPOINTS_REGS + bool + depends on HAVE_HW_BREAKPOINT + help + Depending on the arch implementation of hardware breakpoints, + some of them have separate registers for data and instruction + breakpoints addresses, others have mixed registers to store + them but define the access type in a control register. + Select this option if your arch implements breakpoints under the + latter fashion. + config HAVE_USER_RETURN_NOTIFIER bool diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 8d90564c2bcf..e6d8ab5cfa9d 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -44,6 +44,7 @@ config SUPERH32 select HAVE_FUNCTION_GRAPH_TRACER select HAVE_ARCH_KGDB select HAVE_HW_BREAKPOINT + select HAVE_MIXED_BREAKPOINTS_REGS select PERF_EVENTS if HAVE_HW_BREAKPOINT select ARCH_HIBERNATION_POSSIBLE if MMU diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 97a95dfd1181..01177dcbe261 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -53,6 +53,7 @@ config X86 select HAVE_KERNEL_LZMA select HAVE_KERNEL_LZO select HAVE_HW_BREAKPOINT + select HAVE_MIXED_BREAKPOINTS_REGS select PERF_EVENTS select ANON_INODES select HAVE_ARCH_KMEMCHECK diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index a0aa5a9cfb0e..7e8899093098 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -9,9 +9,12 @@ enum { }; enum { - HW_BREAKPOINT_R = 1, - HW_BREAKPOINT_W = 2, - HW_BREAKPOINT_X = 4, + HW_BREAKPOINT_EMPTY = 0, + HW_BREAKPOINT_R = 1, + HW_BREAKPOINT_W = 2, + HW_BREAKPOINT_RW = HW_BREAKPOINT_R | HW_BREAKPOINT_W, + HW_BREAKPOINT_X = 4, + HW_BREAKPOINT_INVALID = HW_BREAKPOINT_RW | HW_BREAKPOINT_X, }; #ifdef __KERNEL__ diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 89e8a050c43a..8ead1345e33b 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -45,18 +45,28 @@ #include +enum bp_type_idx { + TYPE_INST = 0, +#ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS + TYPE_DATA = 0, +#else + TYPE_DATA = 1, +#endif + TYPE_MAX +}; + /* * Constraints data */ /* Number of pinned cpu breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned); +static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned[TYPE_MAX]); /* Number of pinned task breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[HBP_NUM]); +static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[TYPE_MAX][HBP_NUM]); /* Number of non-pinned cpu/task breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_bp_flexible); +static DEFINE_PER_CPU(unsigned int, nr_bp_flexible[TYPE_MAX]); /* Gather the number of total pinned and un-pinned bp in a cpuset */ struct bp_busy_slots { @@ -67,14 +77,22 @@ struct bp_busy_slots { /* Serialize accesses to the above constraints */ static DEFINE_MUTEX(nr_bp_mutex); +static inline enum bp_type_idx find_slot_idx(struct perf_event *bp) +{ + if (bp->attr.bp_type & HW_BREAKPOINT_RW) + return TYPE_DATA; + + return TYPE_INST; +} + /* * Report the maximum number of pinned breakpoints a task * have in this cpu */ -static unsigned int max_task_bp_pinned(int cpu) +static unsigned int max_task_bp_pinned(int cpu, enum bp_type_idx type) { int i; - unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned, cpu); + unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu); for (i = HBP_NUM -1; i >= 0; i--) { if (tsk_pinned[i] > 0) @@ -84,7 +102,7 @@ static unsigned int max_task_bp_pinned(int cpu) return 0; } -static int task_bp_pinned(struct task_struct *tsk) +static int task_bp_pinned(struct task_struct *tsk, enum bp_type_idx type) { struct perf_event_context *ctx = tsk->perf_event_ctxp; struct list_head *list; @@ -105,7 +123,8 @@ static int task_bp_pinned(struct task_struct *tsk) */ list_for_each_entry(bp, list, event_entry) { if (bp->attr.type == PERF_TYPE_BREAKPOINT) - count++; + if (find_slot_idx(bp) == type) + count++; } raw_spin_unlock_irqrestore(&ctx->lock, flags); @@ -118,18 +137,19 @@ static int task_bp_pinned(struct task_struct *tsk) * a given cpu (cpu > -1) or in all of them (cpu = -1). */ static void -fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp) +fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp, + enum bp_type_idx type) { int cpu = bp->cpu; struct task_struct *tsk = bp->ctx->task; if (cpu >= 0) { - slots->pinned = per_cpu(nr_cpu_bp_pinned, cpu); + slots->pinned = per_cpu(nr_cpu_bp_pinned[type], cpu); if (!tsk) - slots->pinned += max_task_bp_pinned(cpu); + slots->pinned += max_task_bp_pinned(cpu, type); else - slots->pinned += task_bp_pinned(tsk); - slots->flexible = per_cpu(nr_bp_flexible, cpu); + slots->pinned += task_bp_pinned(tsk, type); + slots->flexible = per_cpu(nr_bp_flexible[type], cpu); return; } @@ -137,16 +157,16 @@ fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp) for_each_online_cpu(cpu) { unsigned int nr; - nr = per_cpu(nr_cpu_bp_pinned, cpu); + nr = per_cpu(nr_cpu_bp_pinned[type], cpu); if (!tsk) - nr += max_task_bp_pinned(cpu); + nr += max_task_bp_pinned(cpu, type); else - nr += task_bp_pinned(tsk); + nr += task_bp_pinned(tsk, type); if (nr > slots->pinned) slots->pinned = nr; - nr = per_cpu(nr_bp_flexible, cpu); + nr = per_cpu(nr_bp_flexible[type], cpu); if (nr > slots->flexible) slots->flexible = nr; @@ -156,14 +176,15 @@ fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp) /* * Add a pinned breakpoint for the given task in our constraint table */ -static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable) +static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable, + enum bp_type_idx type) { unsigned int *tsk_pinned; int count = 0; - count = task_bp_pinned(tsk); + count = task_bp_pinned(tsk, type); - tsk_pinned = per_cpu(nr_task_bp_pinned, cpu); + tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu); if (enable) { tsk_pinned[count]++; if (count > 0) @@ -178,7 +199,8 @@ static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable) /* * Add/remove the given breakpoint in our constraint table */ -static void toggle_bp_slot(struct perf_event *bp, bool enable) +static void +toggle_bp_slot(struct perf_event *bp, bool enable, enum bp_type_idx type) { int cpu = bp->cpu; struct task_struct *tsk = bp->ctx->task; @@ -186,20 +208,20 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) /* Pinned counter task profiling */ if (tsk) { if (cpu >= 0) { - toggle_bp_task_slot(tsk, cpu, enable); + toggle_bp_task_slot(tsk, cpu, enable, type); return; } for_each_online_cpu(cpu) - toggle_bp_task_slot(tsk, cpu, enable); + toggle_bp_task_slot(tsk, cpu, enable, type); return; } /* Pinned counter cpu profiling */ if (enable) - per_cpu(nr_cpu_bp_pinned, bp->cpu)++; + per_cpu(nr_cpu_bp_pinned[type], bp->cpu)++; else - per_cpu(nr_cpu_bp_pinned, bp->cpu)--; + per_cpu(nr_cpu_bp_pinned[type], bp->cpu)--; } /* @@ -246,14 +268,21 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) static int __reserve_bp_slot(struct perf_event *bp) { struct bp_busy_slots slots = {0}; + enum bp_type_idx type; - fetch_bp_busy_slots(&slots, bp); + /* Basic checks */ + if (bp->attr.bp_type == HW_BREAKPOINT_EMPTY || + bp->attr.bp_type == HW_BREAKPOINT_INVALID) + return -EINVAL; + + type = find_slot_idx(bp); + fetch_bp_busy_slots(&slots, bp, type); /* Flexible counters need to keep at least one slot */ if (slots.pinned + (!!slots.flexible) == HBP_NUM) return -ENOSPC; - toggle_bp_slot(bp, true); + toggle_bp_slot(bp, true, type); return 0; } @@ -273,7 +302,10 @@ int reserve_bp_slot(struct perf_event *bp) static void __release_bp_slot(struct perf_event *bp) { - toggle_bp_slot(bp, false); + enum bp_type_idx type; + + type = find_slot_idx(bp); + toggle_bp_slot(bp, false, type); } void release_bp_slot(struct perf_event *bp)