diff options
Diffstat (limited to 'kernel/hw_breakpoint.c')
| -rw-r--r-- | kernel/hw_breakpoint.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 974498b858f..684b710cbb9 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -40,20 +40,12 @@ #include <linux/percpu.h> #include <linux/sched.h> #include <linux/init.h> +#include <linux/slab.h> #include <linux/cpu.h> #include <linux/smp.h> #include <linux/hw_breakpoint.h> -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 @@ -63,11 +55,15 @@ enum bp_type_idx { 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[TYPE_MAX][HBP_NUM]); +static DEFINE_PER_CPU(unsigned int, *nr_task_bp_pinned[TYPE_MAX]); /* Number of non-pinned cpu/task breakpoints in a cpu */ static DEFINE_PER_CPU(unsigned int, nr_bp_flexible[TYPE_MAX]); +static int nr_slots[TYPE_MAX]; + +static int constraints_initialized; + /* Gather the number of total pinned and un-pinned bp in a cpuset */ struct bp_busy_slots { unsigned int pinned; @@ -99,7 +95,7 @@ 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[type], cpu); - for (i = HBP_NUM -1; i >= 0; i--) { + for (i = nr_slots[type] - 1; i >= 0; i--) { if (tsk_pinned[i] > 0) return i + 1; } @@ -292,6 +288,10 @@ static int __reserve_bp_slot(struct perf_event *bp) enum bp_type_idx type; int weight; + /* We couldn't initialize breakpoint constraints on boot */ + if (!constraints_initialized) + return -ENOMEM; + /* Basic checks */ if (bp->attr.bp_type == HW_BREAKPOINT_EMPTY || bp->attr.bp_type == HW_BREAKPOINT_INVALID) @@ -304,7 +304,7 @@ static int __reserve_bp_slot(struct perf_event *bp) fetch_this_slot(&slots, weight); /* Flexible counters need to keep at least one slot */ - if (slots.pinned + (!!slots.flexible) > HBP_NUM) + if (slots.pinned + (!!slots.flexible) > nr_slots[type]) return -ENOSPC; toggle_bp_slot(bp, true, type, weight); @@ -551,7 +551,36 @@ static struct notifier_block hw_breakpoint_exceptions_nb = { static int __init init_hw_breakpoint(void) { + unsigned int **task_bp_pinned; + int cpu, err_cpu; + int i; + + for (i = 0; i < TYPE_MAX; i++) + nr_slots[i] = hw_breakpoint_slots(i); + + for_each_possible_cpu(cpu) { + for (i = 0; i < TYPE_MAX; i++) { + task_bp_pinned = &per_cpu(nr_task_bp_pinned[i], cpu); + *task_bp_pinned = kzalloc(sizeof(int) * nr_slots[i], + GFP_KERNEL); + if (!*task_bp_pinned) + goto err_alloc; + } + } + + constraints_initialized = 1; + return register_die_notifier(&hw_breakpoint_exceptions_nb); + + err_alloc: + for_each_possible_cpu(err_cpu) { + if (err_cpu == cpu) + break; + for (i = 0; i < TYPE_MAX; i++) + kfree(per_cpu(nr_task_bp_pinned[i], cpu)); + } + + return -ENOMEM; } core_initcall(init_hw_breakpoint); |