ARM: 6357/1: hw-breakpoint: add new ptrace requests for hw-breakpoint interaction
For debuggers to take advantage of the hw-breakpoint framework in the kernel,
it is necessary to expose the API calls via a ptrace interface.
This patch exposes the hardware breakpoints framework as a collection of
virtual registers, accesible using PTRACE_SETHBPREGS and PTRACE_GETHBPREGS
requests. The breakpoints are stored in the debug_info struct of the running
thread.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/hw_breakpoint.h b/arch/arm/include/asm/hw_breakpoint.h
index 33048c7..4d8ae9d 100644
--- a/arch/arm/include/asm/hw_breakpoint.h
+++ b/arch/arm/include/asm/hw_breakpoint.h
@@ -2,6 +2,11 @@
#define _ARM_HW_BREAKPOINT_H
#ifdef __KERNEL__
+
+struct task_struct;
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+
struct arch_hw_breakpoint_ctrl {
u32 __reserved : 9,
mismatch : 1,
@@ -102,7 +107,6 @@
struct notifier_block;
struct perf_event;
struct pmu;
-struct task_struct;
extern struct pmu perf_ops_bp;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
@@ -111,13 +115,19 @@
extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
+
extern u8 arch_get_debug_arch(void);
extern u8 arch_get_max_wp_len(void);
+extern void clear_ptrace_hw_breakpoint(struct task_struct *tsk);
int arch_install_hw_breakpoint(struct perf_event *bp);
void arch_uninstall_hw_breakpoint(struct perf_event *bp);
void hw_breakpoint_pmu_read(struct perf_event *bp);
int hw_breakpoint_slots(int type);
+#else
+static inline void clear_ptrace_hw_breakpoint(struct task_struct *tsk) {}
+
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif /* __KERNEL__ */
#endif /* _ARM_HW_BREAKPOINT_H */
diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index 7bed3da..67357ba 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -19,6 +19,7 @@
#ifdef __KERNEL__
+#include <asm/hw_breakpoint.h>
#include <asm/ptrace.h>
#include <asm/types.h>
@@ -41,6 +42,9 @@
struct debug_info {
int nsaved;
struct debug_entry bp[2];
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ struct perf_event *hbp[ARM_MAX_HBP_SLOTS];
+#endif
};
struct thread_struct {
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 7ce15eb..783d50f 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -29,6 +29,8 @@
#define PTRACE_SETCRUNCHREGS 26
#define PTRACE_GETVFPREGS 27
#define PTRACE_SETVFPREGS 28
+#define PTRACE_GETHBPREGS 29
+#define PTRACE_SETHBPREGS 30
/*
* PSR bits