diff options
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 74 | ||||
| -rw-r--r-- | include/linux/hw_breakpoint.h | 36 | ||||
| -rw-r--r-- | kernel/hw_breakpoint.c | 87 |
3 files changed, 75 insertions, 122 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 75e0cd847bd..2941b32ea66 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -593,6 +593,34 @@ static unsigned long ptrace_get_dr7(struct perf_event *bp[]) return dr7; } +static struct perf_event * +ptrace_modify_breakpoint(struct perf_event *bp, int len, int type, + struct task_struct *tsk) +{ + int err; + int gen_len, gen_type; + DEFINE_BREAKPOINT_ATTR(attr); + + /* + * We shoud have at least an inactive breakpoint at this + * slot. It means the user is writing dr7 without having + * written the address register first + */ + if (!bp) + return ERR_PTR(-EINVAL); + + err = arch_bp_generic_fields(len, type, &gen_len, &gen_type); + if (err) + return ERR_PTR(err); + + attr = bp->attr; + attr.bp_len = gen_len; + attr.bp_type = gen_type; + attr.disabled = 0; + + return modify_user_hw_breakpoint(bp, &attr, bp->callback, tsk); +} + /* * Handle ptrace writes to debug register 7. */ @@ -603,7 +631,6 @@ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data) int i, orig_ret = 0, rc = 0; int enabled, second_pass = 0; unsigned len, type; - int gen_len, gen_type; struct perf_event *bp; data &= ~DR_CONTROL_RESERVED; @@ -634,33 +661,12 @@ restore: continue; } - /* - * We shoud have at least an inactive breakpoint at this - * slot. It means the user is writing dr7 without having - * written the address register first - */ - if (!bp) { - rc = -EINVAL; - break; - } - - rc = arch_bp_generic_fields(len, type, &gen_len, &gen_type); - if (rc) - break; - - /* - * This is a temporary thing as bp is unregistered/registered - * to simulate modification - */ - bp = modify_user_hw_breakpoint(bp, bp->attr.bp_addr, gen_len, - gen_type, bp->callback, - tsk, true); - thread->ptrace_bps[i] = NULL; + bp = ptrace_modify_breakpoint(bp, len, type, tsk); /* Incorrect bp, or we have a bug in bp API */ if (IS_ERR(bp)) { rc = PTR_ERR(bp); - bp = NULL; + thread->ptrace_bps[i] = NULL; break; } thread->ptrace_bps[i] = bp; @@ -707,24 +713,26 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, { struct perf_event *bp; struct thread_struct *t = &tsk->thread; + DEFINE_BREAKPOINT_ATTR(attr); if (!t->ptrace_bps[nr]) { /* * Put stub len and type to register (reserve) an inactive but * correct bp */ - bp = register_user_hw_breakpoint(addr, HW_BREAKPOINT_LEN_1, - HW_BREAKPOINT_W, - ptrace_triggered, tsk, - false); + attr.bp_addr = addr; + attr.bp_len = HW_BREAKPOINT_LEN_1; + attr.bp_type = HW_BREAKPOINT_W; + attr.disabled = 1; + + bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); } else { bp = t->ptrace_bps[nr]; t->ptrace_bps[nr] = NULL; - bp = modify_user_hw_breakpoint(bp, addr, bp->attr.bp_len, - bp->attr.bp_type, - bp->callback, - tsk, - bp->attr.disabled); + + attr = bp->attr; + attr.bp_addr = addr; + bp = modify_user_hw_breakpoint(bp, &attr, bp->callback, tsk); } /* * CHECKME: the previous code returned -EIO if the addr wasn't a diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index c9f7f7c7b0e..5da472e434b 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -20,6 +20,14 @@ enum { #ifdef CONFIG_HAVE_HW_BREAKPOINT +/* As it's for in-kernel or ptrace use, we want it to be pinned */ +#define DEFINE_BREAKPOINT_ATTR(name) \ +struct perf_event_attr name = { \ + .type = PERF_TYPE_BREAKPOINT, \ + .size = sizeof(name), \ + .pinned = 1, \ +}; + static inline unsigned long hw_breakpoint_addr(struct perf_event *bp) { return bp->attr.bp_addr; @@ -36,22 +44,16 @@ static inline int hw_breakpoint_len(struct perf_event *bp) } extern struct perf_event * -register_user_hw_breakpoint(unsigned long addr, - int len, - int type, +register_user_hw_breakpoint(struct perf_event_attr *attr, perf_callback_t triggered, - struct task_struct *tsk, - bool active); + struct task_struct *tsk); /* FIXME: only change from the attr, and don't unregister */ extern struct perf_event * modify_user_hw_breakpoint(struct perf_event *bp, - unsigned long addr, - int len, - int type, + struct perf_event_attr *attr, perf_callback_t triggered, - struct task_struct *tsk, - bool active); + struct task_struct *tsk); /* * Kernel breakpoints are not associated with any particular thread. @@ -89,20 +91,14 @@ static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp) #else /* !CONFIG_HAVE_HW_BREAKPOINT */ static inline struct perf_event * -register_user_hw_breakpoint(unsigned long addr, - int len, - int type, +register_user_hw_breakpoint(struct perf_event_attr *attr, perf_callback_t triggered, - struct task_struct *tsk, - bool active) { return NULL; } + struct task_struct *tsk) { return NULL; } static inline struct perf_event * modify_user_hw_breakpoint(struct perf_event *bp, - unsigned long addr, - int len, - int type, + struct perf_event_attr *attr, perf_callback_t triggered, - struct task_struct *tsk, - bool active) { return NULL; } + struct task_struct *tsk) { return NULL; } static inline struct perf_event * register_wide_hw_breakpoint_cpu(unsigned long addr, int len, diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 32e1018191b..2a47514f12f 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -289,90 +289,32 @@ int register_perf_hw_breakpoint(struct perf_event *bp) return __register_perf_hw_breakpoint(bp); } -/* - * Register a breakpoint bound to a task and a given cpu. - * If cpu is -1, the breakpoint is active for the task in every cpu - * If the task is -1, the breakpoint is active for every tasks in the given - * cpu. - */ -static struct perf_event * -register_user_hw_breakpoint_cpu(unsigned long addr, - int len, - int type, - perf_callback_t triggered, - pid_t pid, - int cpu, - bool active) -{ - struct perf_event_attr *attr; - struct perf_event *bp; - - attr = kzalloc(sizeof(*attr), GFP_KERNEL); - if (!attr) - return ERR_PTR(-ENOMEM); - - attr->type = PERF_TYPE_BREAKPOINT; - attr->size = sizeof(*attr); - attr->bp_addr = addr; - attr->bp_len = len; - attr->bp_type = type; - /* - * Such breakpoints are used by debuggers to trigger signals when - * we hit the excepted memory op. We can't miss such events, they - * must be pinned. - */ - attr->pinned = 1; - - if (!active) - attr->disabled = 1; - - bp = perf_event_create_kernel_counter(attr, cpu, pid, triggered); - kfree(attr); - - return bp; -} - /** * register_user_hw_breakpoint - register a hardware breakpoint for user space - * @addr: is the memory address that triggers the breakpoint - * @len: the length of the access to the memory (1 byte, 2 bytes etc...) - * @type: the type of the access to the memory (read/write/exec) + * @attr: breakpoint attributes * @triggered: callback to trigger when we hit the breakpoint * @tsk: pointer to 'task_struct' of the process to which the address belongs - * @active: should we activate it while registering it - * */ struct perf_event * -register_user_hw_breakpoint(unsigned long addr, - int len, - int type, +register_user_hw_breakpoint(struct perf_event_attr *attr, perf_callback_t triggered, - struct task_struct *tsk, - bool active) + struct task_struct *tsk) { - return register_user_hw_breakpoint_cpu(addr, len, type, triggered, - tsk->pid, -1, active); + return perf_event_create_kernel_counter(attr, -1, tsk->pid, triggered); } EXPORT_SYMBOL_GPL(register_user_hw_breakpoint); /** * modify_user_hw_breakpoint - modify a user-space hardware breakpoint * @bp: the breakpoint structure to modify - * @addr: is the memory address that triggers the breakpoint - * @len: the length of the access to the memory (1 byte, 2 bytes etc...) - * @type: the type of the access to the memory (read/write/exec) + * @attr: new breakpoint attributes * @triggered: callback to trigger when we hit the breakpoint * @tsk: pointer to 'task_struct' of the process to which the address belongs - * @active: should we activate it while registering it */ struct perf_event * -modify_user_hw_breakpoint(struct perf_event *bp, - unsigned long addr, - int len, - int type, +modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr, perf_callback_t triggered, - struct task_struct *tsk, - bool active) + struct task_struct *tsk) { /* * FIXME: do it without unregistering @@ -381,8 +323,7 @@ modify_user_hw_breakpoint(struct perf_event *bp, */ unregister_hw_breakpoint(bp); - return register_user_hw_breakpoint(addr, len, type, triggered, - tsk, active); + return perf_event_create_kernel_counter(attr, -1, tsk->pid, triggered); } EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint); @@ -406,8 +347,16 @@ register_kernel_hw_breakpoint_cpu(unsigned long addr, int cpu, bool active) { - return register_user_hw_breakpoint_cpu(addr, len, type, triggered, - -1, cpu, active); + DEFINE_BREAKPOINT_ATTR(attr); + + attr.bp_addr = addr; + attr.bp_len = len; + attr.bp_type = type; + + if (!active) + attr.disabled = 1; + + return perf_event_create_kernel_counter(&attr, cpu, -1, triggered); } /** |