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Diffstat (limited to 'kernel')
-rw-r--r--kernel/hw_breakpoint.c56
-rw-r--r--kernel/kgdb.c3
2 files changed, 49 insertions, 10 deletions
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 50dbd5999588..8a5c7d55ac9f 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -243,38 +243,70 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable)
* ((per_cpu(nr_bp_flexible, *) > 1) + max(per_cpu(nr_cpu_bp_pinned, *))
* + max(per_cpu(nr_task_bp_pinned, *))) < HBP_NUM
*/
-int reserve_bp_slot(struct perf_event *bp)
+static int __reserve_bp_slot(struct perf_event *bp)
{
struct bp_busy_slots slots = {0};
- int ret = 0;
-
- mutex_lock(&nr_bp_mutex);
fetch_bp_busy_slots(&slots, bp);
/* Flexible counters need to keep at least one slot */
- if (slots.pinned + (!!slots.flexible) == HBP_NUM) {
- ret = -ENOSPC;
- goto end;
- }
+ if (slots.pinned + (!!slots.flexible) == HBP_NUM)
+ return -ENOSPC;
toggle_bp_slot(bp, true);
-end:
+ return 0;
+}
+
+int reserve_bp_slot(struct perf_event *bp)
+{
+ int ret;
+
+ mutex_lock(&nr_bp_mutex);
+
+ ret = __reserve_bp_slot(bp);
+
mutex_unlock(&nr_bp_mutex);
return ret;
}
+static void __release_bp_slot(struct perf_event *bp)
+{
+ toggle_bp_slot(bp, false);
+}
+
void release_bp_slot(struct perf_event *bp)
{
mutex_lock(&nr_bp_mutex);
- toggle_bp_slot(bp, false);
+ __release_bp_slot(bp);
mutex_unlock(&nr_bp_mutex);
}
+/*
+ * Allow the kernel debugger to reserve breakpoint slots without
+ * taking a lock using the dbg_* variant of for the reserve and
+ * release breakpoint slots.
+ */
+int dbg_reserve_bp_slot(struct perf_event *bp)
+{
+ if (mutex_is_locked(&nr_bp_mutex))
+ return -1;
+
+ return __reserve_bp_slot(bp);
+}
+
+int dbg_release_bp_slot(struct perf_event *bp)
+{
+ if (mutex_is_locked(&nr_bp_mutex))
+ return -1;
+
+ __release_bp_slot(bp);
+
+ return 0;
+}
int register_perf_hw_breakpoint(struct perf_event *bp)
{
@@ -296,6 +328,10 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
if (!bp->attr.disabled || !bp->overflow_handler)
ret = arch_validate_hwbkpt_settings(bp, bp->ctx->task);
+ /* if arch_validate_hwbkpt_settings() fails then release bp slot */
+ if (ret)
+ release_bp_slot(bp);
+
return ret;
}
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 2eb517e23514..c7ade62e4ef0 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -583,6 +583,9 @@ static void kgdb_wait(struct pt_regs *regs)
smp_wmb();
atomic_set(&cpu_in_kgdb[cpu], 1);
+ /* Disable any cpu specific hw breakpoints */
+ kgdb_disable_hw_debug(regs);
+
/* Wait till primary CPU is done with debugging */
while (atomic_read(&passive_cpu_wait[cpu]))
cpu_relax();