diff options
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 57 | ||||
| -rw-r--r-- | include/linux/hw_breakpoint.h | 4 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 5 | ||||
| -rw-r--r-- | kernel/hw_breakpoint.c | 42 | ||||
| -rw-r--r-- | kernel/perf_event.c | 4 |
5 files changed, 66 insertions, 46 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index b361d28..7079dda 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -595,7 +595,7 @@ static unsigned long ptrace_get_dr7(struct perf_event *bp[]) return dr7; } -static struct perf_event * +static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type, struct task_struct *tsk, int disabled) { @@ -609,11 +609,11 @@ ptrace_modify_breakpoint(struct perf_event *bp, int len, int type, * written the address register first */ if (!bp) - return ERR_PTR(-EINVAL); + return -EINVAL; err = arch_bp_generic_fields(len, type, &gen_len, &gen_type); if (err) - return ERR_PTR(err); + return err; attr = bp->attr; attr.bp_len = gen_len; @@ -658,28 +658,17 @@ restore: if (!second_pass) continue; - thread->ptrace_bps[i] = NULL; - bp = ptrace_modify_breakpoint(bp, len, type, + rc = ptrace_modify_breakpoint(bp, len, type, tsk, 1); - if (IS_ERR(bp)) { - rc = PTR_ERR(bp); - thread->ptrace_bps[i] = NULL; + if (rc) break; - } - thread->ptrace_bps[i] = bp; } continue; } - bp = ptrace_modify_breakpoint(bp, len, type, tsk, 0); - - /* Incorrect bp, or we have a bug in bp API */ - if (IS_ERR(bp)) { - rc = PTR_ERR(bp); - thread->ptrace_bps[i] = NULL; + rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0); + if (rc) break; - } - thread->ptrace_bps[i] = bp; } /* * Make a second pass to free the remaining unused breakpoints @@ -737,26 +726,32 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, attr.disabled = 1; bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); + + /* + * CHECKME: the previous code returned -EIO if the addr wasn't + * a valid task virtual addr. The new one will return -EINVAL in + * this case. + * -EINVAL may be what we want for in-kernel breakpoints users, + * but -EIO looks better for ptrace, since we refuse a register + * writing for the user. And anyway this is the previous + * behaviour. + */ + if (IS_ERR(bp)) + return PTR_ERR(bp); + + t->ptrace_bps[nr] = bp; } else { + int err; + bp = t->ptrace_bps[nr]; - t->ptrace_bps[nr] = NULL; attr = bp->attr; attr.bp_addr = addr; - bp = modify_user_hw_breakpoint(bp, &attr); + err = modify_user_hw_breakpoint(bp, &attr); + if (err) + return err; } - /* - * CHECKME: the previous code returned -EIO if the addr wasn't a - * valid task virtual addr. The new one will return -EINVAL in this - * case. - * -EINVAL may be what we want for in-kernel breakpoints users, but - * -EIO looks better for ptrace, since we refuse a register writing - * for the user. And anyway this is the previous behaviour. - */ - if (IS_ERR(bp)) - return PTR_ERR(bp); - t->ptrace_bps[nr] = bp; return 0; } diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index 42da1ce..69f07a9 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -55,7 +55,7 @@ register_user_hw_breakpoint(struct perf_event_attr *attr, struct task_struct *tsk); /* FIXME: only change from the attr, and don't unregister */ -extern struct perf_event * +extern int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr); /* @@ -91,7 +91,7 @@ static inline struct perf_event * register_user_hw_breakpoint(struct perf_event_attr *attr, perf_overflow_handler_t triggered, struct task_struct *tsk) { return NULL; } -static inline struct perf_event * +static inline int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr) { return NULL; } static inline struct perf_event * diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index bf33294..64a53f7 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -872,6 +872,8 @@ extern void perf_output_copy(struct perf_output_handle *handle, const void *buf, unsigned int len); extern int perf_swevent_get_recursion_context(void); extern void perf_swevent_put_recursion_context(int rctx); +extern void perf_event_enable(struct perf_event *event); +extern void perf_event_disable(struct perf_event *event); #else static inline void perf_event_task_sched_in(struct task_struct *task, int cpu) { } @@ -902,7 +904,8 @@ static inline void perf_event_fork(struct task_struct *tsk) { } static inline void perf_event_init(void) { } static inline int perf_swevent_get_recursion_context(void) { return -1; } static inline void perf_swevent_put_recursion_context(int rctx) { } - +static inline void perf_event_enable(struct perf_event *event) { } +static inline void perf_event_disable(struct perf_event *event) { } #endif #define perf_output_put(handle, x) \ diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 03a0773..366eedf 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -320,18 +320,40 @@ EXPORT_SYMBOL_GPL(register_user_hw_breakpoint); * @triggered: callback to trigger when we hit the breakpoint * @tsk: pointer to 'task_struct' of the process to which the address belongs */ -struct perf_event * -modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr) +int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr) { - /* - * FIXME: do it without unregistering - * - We don't want to lose our slot - * - If the new bp is incorrect, don't lose the older one - */ - unregister_hw_breakpoint(bp); + u64 old_addr = bp->attr.bp_addr; + int old_type = bp->attr.bp_type; + int old_len = bp->attr.bp_len; + int err = 0; + + perf_event_disable(bp); + + bp->attr.bp_addr = attr->bp_addr; + bp->attr.bp_type = attr->bp_type; + bp->attr.bp_len = attr->bp_len; + + if (attr->disabled) + goto end; - return perf_event_create_kernel_counter(attr, -1, bp->ctx->task->pid, - bp->overflow_handler); + err = arch_validate_hwbkpt_settings(bp, bp->ctx->task); + if (!err) + perf_event_enable(bp); + + if (err) { + bp->attr.bp_addr = old_addr; + bp->attr.bp_type = old_type; + bp->attr.bp_len = old_len; + if (!bp->attr.disabled) + perf_event_enable(bp); + + return err; + } + +end: + bp->attr.disabled = attr->disabled; + + return 0; } EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint); diff --git a/kernel/perf_event.c b/kernel/perf_event.c index fd43ff4..3b0cf86 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -567,7 +567,7 @@ static void __perf_event_disable(void *info) * is the current context on this CPU and preemption is disabled, * hence we can't get into perf_event_task_sched_out for this context. */ -static void perf_event_disable(struct perf_event *event) +void perf_event_disable(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; struct task_struct *task = ctx->task; @@ -971,7 +971,7 @@ static void __perf_event_enable(void *info) * perf_event_for_each_child or perf_event_for_each as described * for perf_event_disable. */ -static void perf_event_enable(struct perf_event *event) +void perf_event_enable(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; struct task_struct *task = ctx->task; |