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-rw-r--r--arch/Kconfig11
-rw-r--r--arch/sh/Kconfig1
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--include/linux/hw_breakpoint.h9
-rw-r--r--kernel/hw_breakpoint.c86
5 files changed, 78 insertions, 30 deletions
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 <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
*/
/* 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)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 08:08:42 +0000