diff options
| -rw-r--r-- | arch/powerpc/include/asm/hw_breakpoint.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/processor.h | 5 | ||||
| -rw-r--r-- | arch/powerpc/kernel/hw_breakpoint.c | 69 |
3 files changed, 23 insertions, 52 deletions
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h index 84d39fd42f71..66db0147d5b4 100644 --- a/arch/powerpc/include/asm/hw_breakpoint.h +++ b/arch/powerpc/include/asm/hw_breakpoint.h @@ -18,6 +18,7 @@ struct arch_hw_breakpoint { u16 len; /* length of the target data symbol */ u16 hw_len; /* length programmed in hw */ u8 flags; + bool perf_single_step; /* temporarily uninstalled for a perf single step */ }; /* Note: Don't change the first 6 bits below as they are in the same order diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 8a6754ffdc7e..9e67cb1c72e9 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -172,11 +172,6 @@ struct thread_struct { unsigned int align_ctl; /* alignment handling control */ #ifdef CONFIG_HAVE_HW_BREAKPOINT struct perf_event *ptrace_bps[HBP_NUM_MAX]; - /* - * Helps identify source of single-step exception and subsequent - * hw-breakpoint enablement - */ - struct perf_event *last_hit_ubp[HBP_NUM_MAX]; #endif /* CONFIG_HAVE_HW_BREAKPOINT */ struct arch_hw_breakpoint hw_brk[HBP_NUM_MAX]; /* hardware breakpoint info */ unsigned long trap_nr; /* last trap # on this thread */ diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index e6749642604c..624375c18882 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -43,16 +43,6 @@ int hw_breakpoint_slots(int type) return 0; /* no instruction breakpoints available */ } -static bool single_step_pending(void) -{ - int i; - - for (i = 0; i < nr_wp_slots(); i++) { - if (current->thread.last_hit_ubp[i]) - return true; - } - return false; -} /* * Install a perf counter breakpoint. @@ -84,7 +74,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp) * Do not install DABR values if the instruction must be single-stepped. * If so, DABR will be populated in single_step_dabr_instruction(). */ - if (!single_step_pending()) + if (!info->perf_single_step) __set_breakpoint(i, info); return 0; @@ -372,28 +362,6 @@ void arch_release_bp_slot(struct perf_event *bp) } /* - * Perform cleanup of arch-specific counters during unregistration - * of the perf-event - */ -void arch_unregister_hw_breakpoint(struct perf_event *bp) -{ - /* - * If the breakpoint is unregistered between a hw_breakpoint_handler() - * and the single_step_dabr_instruction(), then cleanup the breakpoint - * restoration variables to prevent dangling pointers. - * FIXME, this should not be using bp->ctx at all! Sayeth peterz. - */ - if (bp->ctx && bp->ctx->task && bp->ctx->task != ((void *)-1L)) { - int i; - - for (i = 0; i < nr_wp_slots(); i++) { - if (bp->ctx->task->thread.last_hit_ubp[i] == bp) - bp->ctx->task->thread.last_hit_ubp[i] = NULL; - } - } -} - -/* * Check for virtual address in kernel space. */ int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw) @@ -510,7 +478,9 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs) int i; for (i = 0; i < nr_wp_slots(); i++) { - if (unlikely(tsk->thread.last_hit_ubp[i])) + struct perf_event *bp = __this_cpu_read(bp_per_reg[i]); + + if (unlikely(bp && counter_arch_bp(bp)->perf_single_step)) goto reset; } return; @@ -520,7 +490,7 @@ reset: for (i = 0; i < nr_wp_slots(); i++) { info = counter_arch_bp(__this_cpu_read(bp_per_reg[i])); __set_breakpoint(i, info); - tsk->thread.last_hit_ubp[i] = NULL; + info->perf_single_step = false; } } @@ -563,7 +533,8 @@ static bool stepping_handler(struct pt_regs *regs, struct perf_event **bp, for (i = 0; i < nr_wp_slots(); i++) { if (!hit[i]) continue; - current->thread.last_hit_ubp[i] = bp[i]; + + counter_arch_bp(bp[i])->perf_single_step = true; bp[i] = NULL; } regs_set_return_msr(regs, regs->msr | MSR_SE); @@ -770,24 +741,28 @@ NOKPROBE_SYMBOL(hw_breakpoint_handler); static int single_step_dabr_instruction(struct die_args *args) { struct pt_regs *regs = args->regs; - struct perf_event *bp = NULL; - struct arch_hw_breakpoint *info; - int i; bool found = false; /* * Check if we are single-stepping as a result of a * previous HW Breakpoint exception */ - for (i = 0; i < nr_wp_slots(); i++) { - bp = current->thread.last_hit_ubp[i]; + for (int i = 0; i < nr_wp_slots(); i++) { + struct perf_event *bp; + struct arch_hw_breakpoint *info; + + bp = __this_cpu_read(bp_per_reg[i]); if (!bp) continue; - found = true; info = counter_arch_bp(bp); + if (!info->perf_single_step) + continue; + + found = true; + /* * We shall invoke the user-defined callback function in the * single stepping handler to confirm to 'trigger-after-execute' @@ -795,19 +770,19 @@ static int single_step_dabr_instruction(struct die_args *args) */ if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ)) perf_bp_event(bp, regs); - current->thread.last_hit_ubp[i] = NULL; + + info->perf_single_step = false; } if (!found) return NOTIFY_DONE; - for (i = 0; i < nr_wp_slots(); i++) { - bp = __this_cpu_read(bp_per_reg[i]); + for (int i = 0; i < nr_wp_slots(); i++) { + struct perf_event *bp = __this_cpu_read(bp_per_reg[i]); if (!bp) continue; - info = counter_arch_bp(bp); - __set_breakpoint(i, info); + __set_breakpoint(i, counter_arch_bp(bp)); } /* |