diff options
| -rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 983558eb902..8e9532152bd 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -228,6 +228,13 @@ static int get_num_brps(void) * be put into halting debug mode at any time by an external debugger * but there is nothing we can do to prevent that. */ +static int monitor_mode_enabled(void) +{ + u32 dscr; + ARM_DBG_READ(c1, 0, dscr); + return !!(dscr & ARM_DSCR_MDBGEN); +} + static int enable_monitor_mode(void) { u32 dscr; @@ -321,14 +328,9 @@ int arch_install_hw_breakpoint(struct perf_event *bp) { struct arch_hw_breakpoint *info = counter_arch_bp(bp); struct perf_event **slot, **slots; - int i, max_slots, ctrl_base, val_base, ret = 0; + int i, max_slots, ctrl_base, val_base; u32 addr, ctrl; - /* Ensure that we are in monitor mode and halting mode is disabled. */ - ret = enable_monitor_mode(); - if (ret) - goto out; - addr = info->address; ctrl = encode_ctrl_reg(info->ctrl) | 0x1; @@ -355,10 +357,8 @@ int arch_install_hw_breakpoint(struct perf_event *bp) } } - if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n")) { - ret = -EBUSY; - goto out; - } + if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n")) + return -EBUSY; /* Override the breakpoint data with the step data. */ if (info->step_ctrl.enabled) { @@ -376,9 +376,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp) /* Setup the control register. */ write_wb_reg(ctrl_base + i, ctrl); - -out: - return ret; + return 0; } void arch_uninstall_hw_breakpoint(struct perf_event *bp) @@ -589,6 +587,10 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) int ret = 0; u32 offset, alignment_mask = 0x3; + /* Ensure that we are in monitor debug mode. */ + if (!monitor_mode_enabled()) + return -ENODEV; + /* Build the arch_hw_breakpoint. */ ret = arch_build_bp_info(bp); if (ret) |