diff options
Diffstat (limited to 'arch/powerpc/kernel/ptrace.c')
| -rw-r--r-- | arch/powerpc/kernel/ptrace.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 7a0c0199ea28..11f3cd9c832f 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -32,6 +32,8 @@ #ifdef CONFIG_PPC32 #include <linux/module.h> #endif +#include <linux/hw_breakpoint.h> +#include <linux/perf_event.h> #include <asm/uaccess.h> #include <asm/page.h> @@ -866,9 +868,34 @@ void user_disable_single_step(struct task_struct *task) clear_tsk_thread_flag(task, TIF_SINGLESTEP); } +#ifdef CONFIG_HAVE_HW_BREAKPOINT +void ptrace_triggered(struct perf_event *bp, int nmi, + struct perf_sample_data *data, struct pt_regs *regs) +{ + struct perf_event_attr attr; + + /* + * Disable the breakpoint request here since ptrace has defined a + * one-shot behaviour for breakpoint exceptions in PPC64. + * The SIGTRAP signal is generated automatically for us in do_dabr(). + * We don't have to do anything about that here + */ + attr = bp->attr; + attr.disabled = true; + modify_user_hw_breakpoint(bp, &attr); +} +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ + int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data) { +#ifdef CONFIG_HAVE_HW_BREAKPOINT + int ret; + struct thread_struct *thread = &(task->thread); + struct perf_event *bp; + struct perf_event_attr attr; +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ + /* For ppc64 we support one DABR and no IABR's at the moment (ppc64). * For embedded processors we support one DAC and no IAC's at the * moment. @@ -896,6 +923,43 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, /* Ensure breakpoint translation bit is set */ if (data && !(data & DABR_TRANSLATION)) return -EIO; +#ifdef CONFIG_HAVE_HW_BREAKPOINT + bp = thread->ptrace_bps[0]; + if ((!data) || !(data & (DABR_DATA_WRITE | DABR_DATA_READ))) { + if (bp) { + unregister_hw_breakpoint(bp); + thread->ptrace_bps[0] = NULL; + } + return 0; + } + if (bp) { + attr = bp->attr; + attr.bp_addr = data & ~HW_BREAKPOINT_ALIGN; + arch_bp_generic_fields(data & + (DABR_DATA_WRITE | DABR_DATA_READ), + &attr.bp_type); + ret = modify_user_hw_breakpoint(bp, &attr); + if (ret) + return ret; + thread->ptrace_bps[0] = bp; + thread->dabr = data; + return 0; + } + + /* Create a new breakpoint request if one doesn't exist already */ + hw_breakpoint_init(&attr); + attr.bp_addr = data & ~HW_BREAKPOINT_ALIGN; + arch_bp_generic_fields(data & (DABR_DATA_WRITE | DABR_DATA_READ), + &attr.bp_type); + + thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr, + ptrace_triggered, task); + if (IS_ERR(bp)) { + thread->ptrace_bps[0] = NULL; + return PTR_ERR(bp); + } + +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ /* Move contents to the DABR register */ task->thread.dabr = data; |