To pick up fixes.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
"post_handler," if any, that is associated with the kprobe.
Execution then continues with the instruction following the probepoint.
+Changing Execution Path
+-----------------------
+
+Since kprobes can probe into a running kernel code, it can change the
+register set, including instruction pointer. This operation requires
+maximum care, such as keeping the stack frame, recovering the execution
+path etc. Since it operates on a running kernel and needs deep knowledge
+of computer architecture and concurrent computing, you can easily shoot
+your foot.
+
+If you change the instruction pointer (and set up other related
+registers) in pre_handler, you must return !0 so that kprobes stops
+single stepping and just returns to the given address.
+This also means post_handler should not be called anymore.
+
+Note that this operation may be harder on some architectures which use
+TOC (Table of Contents) for function call, since you have to setup a new
+TOC for your function in your module, and recover the old one after
+returning from it.
+
Return Probes
-------------
tweak the kernel's execution path, you need to suppress optimization,
using one of the following techniques:
-- Specify an empty function for the kprobe's post_handler or break_handler.
+- Specify an empty function for the kprobe's post_handler.
or
the bad probe, are safely unregistered before the register_*probes
function returns.
-- kps/rps/jps: an array of pointers to ``*probe`` data structures
+- kps/rps: an array of pointers to ``*probe`` data structures
- num: the number of the array entries.
.. note::
Kprobes does not use mutexes or allocate memory except during
registration and unregistration.
-Probe handlers are run with preemption disabled. Depending on the
-architecture and optimization state, handlers may also run with
-interrupts disabled (e.g., kretprobe handlers and optimized kprobe
-handlers run without interrupt disabled on x86/x86-64). In any case,
-your handler should not yield the CPU (e.g., by attempting to acquire
-a semaphore).
+Probe handlers are run with preemption disabled or interrupt disabled,
+which depends on the architecture and optimization state. (e.g.,
+kretprobe handlers and optimized kprobe handlers run without interrupt
+disabled on x86/x86-64). In any case, your handler should not yield
+the CPU (e.g., by attempting to acquire a semaphore, or waiting I/O).
Since a return probe is implemented by replacing the return
address with the trampoline's address, stack backtraces and calls
struct kprobe_ctlblk {
unsigned int kprobe_status;
- struct pt_regs jprobe_saved_regs;
- char jprobes_stack[MAX_STACK_SIZE];
struct prev_kprobe prev_kprobe;
};
/* If we have no pre-handler or it returned 0, we continue with
* normal processing. If we have a pre-handler and it returned
- * non-zero - which is expected from setjmp_pre_handler for
- * jprobe, we return without single stepping and leave that to
- * the break-handler which is invoked by a kprobe from
- * jprobe_return
+ * non-zero - which means user handler setup registers to exit
+ * to another instruction, we must skip the single stepping.
*/
if (!p->pre_handler || !p->pre_handler(p, regs)) {
setup_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
+ } else {
+ reset_current_kprobe();
+ preempt_enable_no_resched();
}
return 1;
- } else if (kprobe_running()) {
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- setup_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_HIT_SS;
- return 1;
- }
}
/* no_kprobe: */
return ret;
}
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long sp_addr = regs->sp;
-
- kcb->jprobe_saved_regs = *regs;
- memcpy(kcb->jprobes_stack, (void *)sp_addr, MIN_STACK_SIZE(sp_addr));
- regs->ret = (unsigned long)(jp->entry);
-
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- __asm__ __volatile__("unimp_s");
- return;
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long sp_addr;
-
- *regs = kcb->jprobe_saved_regs;
- sp_addr = regs->sp;
- memcpy((void *)sp_addr, kcb->jprobes_stack, MIN_STACK_SIZE(sp_addr));
- preempt_enable_no_resched();
-
- return 1;
-}
-
static void __used kretprobe_trampoline_holder(void)
{
__asm__ __volatile__(".global kretprobe_trampoline\n"
kretprobe_assert(ri, orig_ret_address, trampoline_address);
regs->ret = orig_ret_address;
- reset_current_kprobe();
kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
asm volatile("mcr p14, 0, %0, " #N "," #M ", " #OP2 : : "r" (VAL));\
} while (0)
+struct perf_event_attr;
struct notifier_block;
struct perf_event;
struct pmu;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
int *gen_len, int *gen_type);
-extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
-extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
+extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
struct kprobe_ctlblk {
unsigned int kprobe_status;
struct prev_kprobe prev_kprobe;
- struct pt_regs jprobe_saved_regs;
- char jprobes_stack[MAX_STACK_SIZE];
};
void arch_remove_kprobe(struct kprobe *);
* We assume one instruction can consume at most 64 bytes stack, which is
* 'push {r0-r15}'. Instructions consume more or unknown stack space like
* 'str r0, [sp, #-80]' and 'str r0, [sp, r1]' should be prohibit to probe.
- * Both kprobe and jprobe use this macro.
*/
#define MAX_STACK_SIZE 64
/*
* Check whether bp virtual address is in kernel space.
*/
-int arch_check_bp_in_kernelspace(struct perf_event *bp)
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
{
unsigned int len;
unsigned long va;
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
- va = info->address;
- len = get_hbp_len(info->ctrl.len);
+ va = hw->address;
+ len = get_hbp_len(hw->ctrl.len);
return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
}
/*
* Construct an arch_hw_breakpoint from a perf_event.
*/
-static int arch_build_bp_info(struct perf_event *bp)
+static int arch_build_bp_info(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-
/* Type */
- switch (bp->attr.bp_type) {
+ switch (attr->bp_type) {
case HW_BREAKPOINT_X:
- info->ctrl.type = ARM_BREAKPOINT_EXECUTE;
+ hw->ctrl.type = ARM_BREAKPOINT_EXECUTE;
break;
case HW_BREAKPOINT_R:
- info->ctrl.type = ARM_BREAKPOINT_LOAD;
+ hw->ctrl.type = ARM_BREAKPOINT_LOAD;
break;
case HW_BREAKPOINT_W:
- info->ctrl.type = ARM_BREAKPOINT_STORE;
+ hw->ctrl.type = ARM_BREAKPOINT_STORE;
break;
case HW_BREAKPOINT_RW:
- info->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;
+ hw->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;
break;
default:
return -EINVAL;
}
/* Len */
- switch (bp->attr.bp_len) {
+ switch (attr->bp_len) {
case HW_BREAKPOINT_LEN_1:
- info->ctrl.len = ARM_BREAKPOINT_LEN_1;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_1;
break;
case HW_BREAKPOINT_LEN_2:
- info->ctrl.len = ARM_BREAKPOINT_LEN_2;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_2;
break;
case HW_BREAKPOINT_LEN_4:
- info->ctrl.len = ARM_BREAKPOINT_LEN_4;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_4;
break;
case HW_BREAKPOINT_LEN_8:
- info->ctrl.len = ARM_BREAKPOINT_LEN_8;
- if ((info->ctrl.type != ARM_BREAKPOINT_EXECUTE)
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_8;
+ if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
&& max_watchpoint_len >= 8)
break;
default:
* by the hardware and must be aligned to the appropriate number of
* bytes.
*/
- if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE &&
- info->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
- info->ctrl.len != ARM_BREAKPOINT_LEN_4)
+ if (hw->ctrl.type == ARM_BREAKPOINT_EXECUTE &&
+ hw->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
+ hw->ctrl.len != ARM_BREAKPOINT_LEN_4)
return -EINVAL;
/* Address */
- info->address = bp->attr.bp_addr;
+ hw->address = attr->bp_addr;
/* Privilege */
- info->ctrl.privilege = ARM_BREAKPOINT_USER;
- if (arch_check_bp_in_kernelspace(bp))
- info->ctrl.privilege |= ARM_BREAKPOINT_PRIV;
+ hw->ctrl.privilege = ARM_BREAKPOINT_USER;
+ if (arch_check_bp_in_kernelspace(hw))
+ hw->ctrl.privilege |= ARM_BREAKPOINT_PRIV;
/* Enabled? */
- info->ctrl.enabled = !bp->attr.disabled;
+ hw->ctrl.enabled = !attr->disabled;
/* Mismatch */
- info->ctrl.mismatch = 0;
+ hw->ctrl.mismatch = 0;
return 0;
}
/*
* Validate the arch-specific HW Breakpoint register settings.
*/
-int arch_validate_hwbkpt_settings(struct perf_event *bp)
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
int ret = 0;
u32 offset, alignment_mask = 0x3;
return -ENODEV;
/* Build the arch_hw_breakpoint. */
- ret = arch_build_bp_info(bp);
+ ret = arch_build_bp_info(bp, attr, hw);
if (ret)
goto out;
/* Check address alignment. */
- if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_8)
alignment_mask = 0x7;
- offset = info->address & alignment_mask;
+ offset = hw->address & alignment_mask;
switch (offset) {
case 0:
/* Aligned */
case 1:
case 2:
/* Allow halfword watchpoints and breakpoints. */
- if (info->ctrl.len == ARM_BREAKPOINT_LEN_2)
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
break;
case 3:
/* Allow single byte watchpoint. */
- if (info->ctrl.len == ARM_BREAKPOINT_LEN_1)
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
break;
default:
ret = -EINVAL;
goto out;
}
- info->address &= ~alignment_mask;
- info->ctrl.len <<= offset;
+ hw->address &= ~alignment_mask;
+ hw->ctrl.len <<= offset;
if (is_default_overflow_handler(bp)) {
/*
return -EINVAL;
/* We don't allow mismatch breakpoints in kernel space. */
- if (arch_check_bp_in_kernelspace(bp))
+ if (arch_check_bp_in_kernelspace(hw))
return -EPERM;
/*
* reports them.
*/
if (!debug_exception_updates_fsr() &&
- (info->ctrl.type == ARM_BREAKPOINT_LOAD ||
- info->ctrl.type == ARM_BREAKPOINT_STORE))
+ (hw->ctrl.type == ARM_BREAKPOINT_LOAD ||
+ hw->ctrl.type == ARM_BREAKPOINT_STORE))
return -EINVAL;
}
(unsigned long)(addr) + \
(size))
-/* Used as a marker in ARM_pc to note when we're in a jprobe. */
-#define JPROBE_MAGIC_ADDR 0xffffffff
-
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
break;
case KPROBE_REENTER:
/* A nested probe was hit in FIQ, it is a BUG */
- pr_warn("Unrecoverable kprobe detected at %p.\n",
- p->addr);
+ pr_warn("Unrecoverable kprobe detected.\n");
+ dump_kprobe(p);
/* fall through */
default:
/* impossible cases */
/*
* If we have no pre-handler or it returned 0, we
- * continue with normal processing. If we have a
- * pre-handler and it returned non-zero, it prepped
- * for calling the break_handler below on re-entry,
- * so get out doing nothing more here.
+ * continue with normal processing. If we have a
+ * pre-handler and it returned non-zero, it will
+ * modify the execution path and no need to single
+ * stepping. Let's just reset current kprobe and exit.
*/
if (!p->pre_handler || !p->pre_handler(p, regs)) {
kcb->kprobe_status = KPROBE_HIT_SS;
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
}
- reset_current_kprobe();
- }
- }
- } else if (cur) {
- /* We probably hit a jprobe. Call its break handler. */
- if (cur->break_handler && cur->break_handler(cur, regs)) {
- kcb->kprobe_status = KPROBE_HIT_SS;
- singlestep(cur, regs, kcb);
- if (cur->post_handler) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- cur->post_handler(cur, regs, 0);
}
+ reset_current_kprobe();
}
- reset_current_kprobe();
} else {
/*
* The probe was removed and a race is in progress.
regs->ARM_lr = (unsigned long)&kretprobe_trampoline;
}
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- long sp_addr = regs->ARM_sp;
- long cpsr;
-
- kcb->jprobe_saved_regs = *regs;
- memcpy(kcb->jprobes_stack, (void *)sp_addr, MIN_STACK_SIZE(sp_addr));
- regs->ARM_pc = (long)jp->entry;
-
- cpsr = regs->ARM_cpsr | PSR_I_BIT;
-#ifdef CONFIG_THUMB2_KERNEL
- /* Set correct Thumb state in cpsr */
- if (regs->ARM_pc & 1)
- cpsr |= PSR_T_BIT;
- else
- cpsr &= ~PSR_T_BIT;
-#endif
- regs->ARM_cpsr = cpsr;
-
- preempt_disable();
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- __asm__ __volatile__ (
- /*
- * Setup an empty pt_regs. Fill SP and PC fields as
- * they're needed by longjmp_break_handler.
- *
- * We allocate some slack between the original SP and start of
- * our fabricated regs. To be precise we want to have worst case
- * covered which is STMFD with all 16 regs so we allocate 2 *
- * sizeof(struct_pt_regs)).
- *
- * This is to prevent any simulated instruction from writing
- * over the regs when they are accessing the stack.
- */
-#ifdef CONFIG_THUMB2_KERNEL
- "sub r0, %0, %1 \n\t"
- "mov sp, r0 \n\t"
-#else
- "sub sp, %0, %1 \n\t"
-#endif
- "ldr r0, ="__stringify(JPROBE_MAGIC_ADDR)"\n\t"
- "str %0, [sp, %2] \n\t"
- "str r0, [sp, %3] \n\t"
- "mov r0, sp \n\t"
- "bl kprobe_handler \n\t"
-
- /*
- * Return to the context saved by setjmp_pre_handler
- * and restored by longjmp_break_handler.
- */
-#ifdef CONFIG_THUMB2_KERNEL
- "ldr lr, [sp, %2] \n\t" /* lr = saved sp */
- "ldrd r0, r1, [sp, %5] \n\t" /* r0,r1 = saved lr,pc */
- "ldr r2, [sp, %4] \n\t" /* r2 = saved psr */
- "stmdb lr!, {r0, r1, r2} \n\t" /* push saved lr and */
- /* rfe context */
- "ldmia sp, {r0 - r12} \n\t"
- "mov sp, lr \n\t"
- "ldr lr, [sp], #4 \n\t"
- "rfeia sp! \n\t"
-#else
- "ldr r0, [sp, %4] \n\t"
- "msr cpsr_cxsf, r0 \n\t"
- "ldmia sp, {r0 - pc} \n\t"
-#endif
- :
- : "r" (kcb->jprobe_saved_regs.ARM_sp),
- "I" (sizeof(struct pt_regs) * 2),
- "J" (offsetof(struct pt_regs, ARM_sp)),
- "J" (offsetof(struct pt_regs, ARM_pc)),
- "J" (offsetof(struct pt_regs, ARM_cpsr)),
- "J" (offsetof(struct pt_regs, ARM_lr))
- : "memory", "cc");
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- long stack_addr = kcb->jprobe_saved_regs.ARM_sp;
- long orig_sp = regs->ARM_sp;
- struct jprobe *jp = container_of(p, struct jprobe, kp);
-
- if (regs->ARM_pc == JPROBE_MAGIC_ADDR) {
- if (orig_sp != stack_addr) {
- struct pt_regs *saved_regs =
- (struct pt_regs *)kcb->jprobe_saved_regs.ARM_sp;
- printk("current sp %lx does not match saved sp %lx\n",
- orig_sp, stack_addr);
- printk("Saved registers for jprobe %p\n", jp);
- show_regs(saved_regs);
- printk("Current registers\n");
- show_regs(regs);
- BUG();
- }
- *regs = kcb->jprobe_saved_regs;
- memcpy((void *)stack_addr, kcb->jprobes_stack,
- MIN_STACK_SIZE(stack_addr));
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
{
return 0;
print_registers(&result_regs);
if (mem) {
- pr_err("current_stack=%p\n", current_stack);
pr_err("expected_memory:\n");
print_memory(expected_memory, mem_size);
pr_err("result_memory:\n");
struct task_struct;
struct notifier_block;
+struct perf_event_attr;
struct perf_event;
struct pmu;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
int *gen_len, int *gen_type, int *offset);
-extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
-extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
+extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
unsigned long saved_irqflag;
struct prev_kprobe prev_kprobe;
struct kprobe_step_ctx ss_ctx;
- struct pt_regs jprobe_saved_regs;
};
void arch_remove_kprobe(struct kprobe *);
/*
* Check whether bp virtual address is in kernel space.
*/
-int arch_check_bp_in_kernelspace(struct perf_event *bp)
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
{
unsigned int len;
unsigned long va;
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
- va = info->address;
- len = get_hbp_len(info->ctrl.len);
+ va = hw->address;
+ len = get_hbp_len(hw->ctrl.len);
return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
}
/*
* Construct an arch_hw_breakpoint from a perf_event.
*/
-static int arch_build_bp_info(struct perf_event *bp)
+static int arch_build_bp_info(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-
/* Type */
- switch (bp->attr.bp_type) {
+ switch (attr->bp_type) {
case HW_BREAKPOINT_X:
- info->ctrl.type = ARM_BREAKPOINT_EXECUTE;
+ hw->ctrl.type = ARM_BREAKPOINT_EXECUTE;
break;
case HW_BREAKPOINT_R:
- info->ctrl.type = ARM_BREAKPOINT_LOAD;
+ hw->ctrl.type = ARM_BREAKPOINT_LOAD;
break;
case HW_BREAKPOINT_W:
- info->ctrl.type = ARM_BREAKPOINT_STORE;
+ hw->ctrl.type = ARM_BREAKPOINT_STORE;
break;
case HW_BREAKPOINT_RW:
- info->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;
+ hw->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;
break;
default:
return -EINVAL;
}
/* Len */
- switch (bp->attr.bp_len) {
+ switch (attr->bp_len) {
case HW_BREAKPOINT_LEN_1:
- info->ctrl.len = ARM_BREAKPOINT_LEN_1;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_1;
break;
case HW_BREAKPOINT_LEN_2:
- info->ctrl.len = ARM_BREAKPOINT_LEN_2;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_2;
break;
case HW_BREAKPOINT_LEN_3:
- info->ctrl.len = ARM_BREAKPOINT_LEN_3;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_3;
break;
case HW_BREAKPOINT_LEN_4:
- info->ctrl.len = ARM_BREAKPOINT_LEN_4;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_4;
break;
case HW_BREAKPOINT_LEN_5:
- info->ctrl.len = ARM_BREAKPOINT_LEN_5;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_5;
break;
case HW_BREAKPOINT_LEN_6:
- info->ctrl.len = ARM_BREAKPOINT_LEN_6;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_6;
break;
case HW_BREAKPOINT_LEN_7:
- info->ctrl.len = ARM_BREAKPOINT_LEN_7;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_7;
break;
case HW_BREAKPOINT_LEN_8:
- info->ctrl.len = ARM_BREAKPOINT_LEN_8;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_8;
break;
default:
return -EINVAL;
* AArch32 also requires breakpoints of length 2 for Thumb.
* Watchpoints can be of length 1, 2, 4 or 8 bytes.
*/
- if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
+ if (hw->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
if (is_compat_bp(bp)) {
- if (info->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
- info->ctrl.len != ARM_BREAKPOINT_LEN_4)
+ if (hw->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
+ hw->ctrl.len != ARM_BREAKPOINT_LEN_4)
return -EINVAL;
- } else if (info->ctrl.len != ARM_BREAKPOINT_LEN_4) {
+ } else if (hw->ctrl.len != ARM_BREAKPOINT_LEN_4) {
/*
* FIXME: Some tools (I'm looking at you perf) assume
* that breakpoints should be sizeof(long). This
* is nonsense. For now, we fix up the parameter
* but we should probably return -EINVAL instead.
*/
- info->ctrl.len = ARM_BREAKPOINT_LEN_4;
+ hw->ctrl.len = ARM_BREAKPOINT_LEN_4;
}
}
/* Address */
- info->address = bp->attr.bp_addr;
+ hw->address = attr->bp_addr;
/*
* Privilege
* Note that we disallow combined EL0/EL1 breakpoints because
* that would complicate the stepping code.
*/
- if (arch_check_bp_in_kernelspace(bp))
- info->ctrl.privilege = AARCH64_BREAKPOINT_EL1;
+ if (arch_check_bp_in_kernelspace(hw))
+ hw->ctrl.privilege = AARCH64_BREAKPOINT_EL1;
else
- info->ctrl.privilege = AARCH64_BREAKPOINT_EL0;
+ hw->ctrl.privilege = AARCH64_BREAKPOINT_EL0;
/* Enabled? */
- info->ctrl.enabled = !bp->attr.disabled;
+ hw->ctrl.enabled = !attr->disabled;
return 0;
}
/*
* Validate the arch-specific HW Breakpoint register settings.
*/
-int arch_validate_hwbkpt_settings(struct perf_event *bp)
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
int ret;
u64 alignment_mask, offset;
/* Build the arch_hw_breakpoint. */
- ret = arch_build_bp_info(bp);
+ ret = arch_build_bp_info(bp, attr, hw);
if (ret)
return ret;
* that here.
*/
if (is_compat_bp(bp)) {
- if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_8)
alignment_mask = 0x7;
else
alignment_mask = 0x3;
- offset = info->address & alignment_mask;
+ offset = hw->address & alignment_mask;
switch (offset) {
case 0:
/* Aligned */
break;
case 1:
/* Allow single byte watchpoint. */
- if (info->ctrl.len == ARM_BREAKPOINT_LEN_1)
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
break;
case 2:
/* Allow halfword watchpoints and breakpoints. */
- if (info->ctrl.len == ARM_BREAKPOINT_LEN_2)
+ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
break;
default:
return -EINVAL;
}
} else {
- if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE)
+ if (hw->ctrl.type == ARM_BREAKPOINT_EXECUTE)
alignment_mask = 0x3;
else
alignment_mask = 0x7;
- offset = info->address & alignment_mask;
+ offset = hw->address & alignment_mask;
}
- info->address &= ~alignment_mask;
- info->ctrl.len <<= offset;
+ hw->address &= ~alignment_mask;
+ hw->ctrl.len <<= offset;
/*
* Disallow per-task kernel breakpoints since these would
* complicate the stepping code.
*/
- if (info->ctrl.privilege == AARCH64_BREAKPOINT_EL1 && bp->hw.target)
+ if (hw->ctrl.privilege == AARCH64_BREAKPOINT_EL1 && bp->hw.target)
return -EINVAL;
return 0;
break;
case KPROBE_HIT_SS:
case KPROBE_REENTER:
- pr_warn("Unrecoverable kprobe detected at %p.\n", p->addr);
+ pr_warn("Unrecoverable kprobe detected.\n");
dump_kprobe(p);
BUG();
break;
/*
* If we have no pre-handler or it returned 0, we
* continue with normal processing. If we have a
- * pre-handler and it returned non-zero, it prepped
- * for calling the break_handler below on re-entry,
- * so get out doing nothing more here.
+ * pre-handler and it returned non-zero, it will
+ * modify the execution path and no need to single
+ * stepping. Let's just reset current kprobe and exit.
*
* pre_handler can hit a breakpoint and can step thru
* before return, keep PSTATE D-flag enabled until
*/
if (!p->pre_handler || !p->pre_handler(p, regs)) {
setup_singlestep(p, regs, kcb, 0);
- return;
- }
- }
- } else if ((le32_to_cpu(*(kprobe_opcode_t *) addr) ==
- BRK64_OPCODE_KPROBES) && cur_kprobe) {
- /* We probably hit a jprobe. Call its break handler. */
- if (cur_kprobe->break_handler &&
- cur_kprobe->break_handler(cur_kprobe, regs)) {
- setup_singlestep(cur_kprobe, regs, kcb, 0);
- return;
+ } else
+ reset_current_kprobe();
}
}
/*
return DBG_HOOK_HANDLED;
}
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- kcb->jprobe_saved_regs = *regs;
- /*
- * Since we can't be sure where in the stack frame "stacked"
- * pass-by-value arguments are stored we just don't try to
- * duplicate any of the stack. Do not use jprobes on functions that
- * use more than 64 bytes (after padding each to an 8 byte boundary)
- * of arguments, or pass individual arguments larger than 16 bytes.
- */
-
- instruction_pointer_set(regs, (unsigned long) jp->entry);
- preempt_disable();
- pause_graph_tracing();
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- /*
- * Jprobe handler return by entering break exception,
- * encoded same as kprobe, but with following conditions
- * -a special PC to identify it from the other kprobes.
- * -restore stack addr to original saved pt_regs
- */
- asm volatile(" mov sp, %0 \n"
- "jprobe_return_break: brk %1 \n"
- :
- : "r" (kcb->jprobe_saved_regs.sp),
- "I" (BRK64_ESR_KPROBES)
- : "memory");
-
- unreachable();
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- long stack_addr = kcb->jprobe_saved_regs.sp;
- long orig_sp = kernel_stack_pointer(regs);
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- extern const char jprobe_return_break[];
-
- if (instruction_pointer(regs) != (u64) jprobe_return_break)
- return 0;
-
- if (orig_sp != stack_addr) {
- struct pt_regs *saved_regs =
- (struct pt_regs *)kcb->jprobe_saved_regs.sp;
- pr_err("current sp %lx does not match saved sp %lx\n",
- orig_sp, stack_addr);
- pr_err("Saved registers for jprobe %p\n", jp);
- __show_regs(saved_regs);
- pr_err("Current registers\n");
- __show_regs(regs);
- BUG();
- }
- unpause_graph_tracing();
- *regs = kcb->jprobe_saved_regs;
- preempt_enable_no_resched();
- return 1;
-}
-
bool arch_within_kprobe_blacklist(unsigned long addr)
{
if ((addr >= (unsigned long)__kprobes_text_start &&
#define ARCH_PREV_KPROBE_SZ 2
struct kprobe_ctlblk {
unsigned long kprobe_status;
- struct pt_regs jprobe_saved_regs;
- unsigned long jprobes_saved_stacked_regs[MAX_PARAM_RSE_SIZE];
unsigned long *bsp;
unsigned long cfm;
atomic_t prev_kprobe_index;
*/
#define __IA64_BREAK_KDB 0x80100
#define __IA64_BREAK_KPROBE 0x81000 /* .. 0x81fff */
-#define __IA64_BREAK_JPROBE 0x82000
/*
* OS-specific break numbers:
obj-$(CONFIG_PERFMON) += perfmon_default_smpl.o
obj-$(CONFIG_IA64_CYCLONE) += cyclone.o
obj-$(CONFIG_IA64_MCA_RECOVERY) += mca_recovery.o
-obj-$(CONFIG_KPROBES) += kprobes.o jprobes.o
+obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
+++ /dev/null
-/*
- * Jprobe specific operations
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright (C) Intel Corporation, 2005
- *
- * 2005-May Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
- * <anil.s.keshavamurthy@intel.com> initial implementation
- *
- * Jprobes (a.k.a. "jump probes" which is built on-top of kprobes) allow a
- * probe to be inserted into the beginning of a function call. The fundamental
- * difference between a jprobe and a kprobe is the jprobe handler is executed
- * in the same context as the target function, while the kprobe handlers
- * are executed in interrupt context.
- *
- * For jprobes we initially gain control by placing a break point in the
- * first instruction of the targeted function. When we catch that specific
- * break, we:
- * * set the return address to our jprobe_inst_return() function
- * * jump to the jprobe handler function
- *
- * Since we fixed up the return address, the jprobe handler will return to our
- * jprobe_inst_return() function, giving us control again. At this point we
- * are back in the parents frame marker, so we do yet another call to our
- * jprobe_break() function to fix up the frame marker as it would normally
- * exist in the target function.
- *
- * Our jprobe_return function then transfers control back to kprobes.c by
- * executing a break instruction using one of our reserved numbers. When we
- * catch that break in kprobes.c, we continue like we do for a normal kprobe
- * by single stepping the emulated instruction, and then returning execution
- * to the correct location.
- */
-#include <asm/asmmacro.h>
-#include <asm/break.h>
-
- /*
- * void jprobe_break(void)
- */
- .section .kprobes.text, "ax"
-ENTRY(jprobe_break)
- break.m __IA64_BREAK_JPROBE
-END(jprobe_break)
-
- /*
- * void jprobe_inst_return(void)
- */
-GLOBAL_ENTRY(jprobe_inst_return)
- br.call.sptk.many b0=jprobe_break
-END(jprobe_inst_return)
-
-GLOBAL_ENTRY(invalidate_stacked_regs)
- movl r16=invalidate_restore_cfm
- ;;
- mov b6=r16
- ;;
- br.ret.sptk.many b6
- ;;
-invalidate_restore_cfm:
- mov r16=ar.rsc
- ;;
- mov ar.rsc=r0
- ;;
- loadrs
- ;;
- mov ar.rsc=r16
- ;;
- br.cond.sptk.many rp
-END(invalidate_stacked_regs)
-
-GLOBAL_ENTRY(flush_register_stack)
- // flush dirty regs to backing store (must be first in insn group)
- flushrs
- ;;
- br.ret.sptk.many rp
-END(flush_register_stack)
-
#include <asm/sections.h>
#include <asm/exception.h>
-extern void jprobe_inst_return(void);
-
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
*/
break;
}
-
kretprobe_assert(ri, orig_ret_address, trampoline_address);
- reset_current_kprobe();
kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
prepare_ss(p, regs);
kcb->kprobe_status = KPROBE_REENTER;
return 1;
- } else if (args->err == __IA64_BREAK_JPROBE) {
- /*
- * jprobe instrumented function just completed
- */
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- goto ss_probe;
- }
} else if (!is_ia64_break_inst(regs)) {
/* The breakpoint instruction was removed by
* another cpu right after we hit, no further
set_current_kprobe(p, kcb);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- if (p->pre_handler && p->pre_handler(p, regs))
- /*
- * Our pre-handler is specifically requesting that we just
- * do a return. This is used for both the jprobe pre-handler
- * and the kretprobe trampoline
- */
+ if (p->pre_handler && p->pre_handler(p, regs)) {
+ reset_current_kprobe();
+ preempt_enable_no_resched();
return 1;
+ }
-ss_probe:
#if !defined(CONFIG_PREEMPT)
if (p->ainsn.inst_flag == INST_FLAG_BOOSTABLE && !p->post_handler) {
/* Boost up -- we can execute copied instructions directly */
case DIE_BREAK:
/* err is break number from ia64_bad_break() */
if ((args->err >> 12) == (__IA64_BREAK_KPROBE >> 12)
- || args->err == __IA64_BREAK_JPROBE
|| args->err == 0)
if (pre_kprobes_handler(args))
ret = NOTIFY_STOP;
return ((struct fnptr *)entry)->ip;
}
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- unsigned long addr = arch_deref_entry_point(jp->entry);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- struct param_bsp_cfm pa;
- int bytes;
-
- /*
- * Callee owns the argument space and could overwrite it, eg
- * tail call optimization. So to be absolutely safe
- * we save the argument space before transferring the control
- * to instrumented jprobe function which runs in
- * the process context
- */
- pa.ip = regs->cr_iip;
- unw_init_running(ia64_get_bsp_cfm, &pa);
- bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f)
- - (char *)pa.bsp;
- memcpy( kcb->jprobes_saved_stacked_regs,
- pa.bsp,
- bytes );
- kcb->bsp = pa.bsp;
- kcb->cfm = pa.cfm;
-
- /* save architectural state */
- kcb->jprobe_saved_regs = *regs;
-
- /* after rfi, execute the jprobe instrumented function */
- regs->cr_iip = addr & ~0xFULL;
- ia64_psr(regs)->ri = addr & 0xf;
- regs->r1 = ((struct fnptr *)(jp->entry))->gp;
-
- /*
- * fix the return address to our jprobe_inst_return() function
- * in the jprobes.S file
- */
- regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip;
-
- return 1;
-}
-
-/* ia64 does not need this */
-void __kprobes jprobe_return(void)
-{
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- int bytes;
-
- /* restoring architectural state */
- *regs = kcb->jprobe_saved_regs;
-
- /* restoring the original argument space */
- flush_register_stack();
- bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f)
- - (char *)kcb->bsp;
- memcpy( kcb->bsp,
- kcb->jprobes_saved_stacked_regs,
- bytes );
- invalidate_stacked_regs();
-
- preempt_enable_no_resched();
- return 1;
-}
-
static struct kprobe trampoline_p = {
.pre_handler = trampoline_probe_handler
};
unsigned long saved_epc;
};
-#define MAX_JPROBES_STACK_SIZE 128
-#define MAX_JPROBES_STACK_ADDR \
- (((unsigned long)current_thread_info()) + THREAD_SIZE - 32 - sizeof(struct pt_regs))
-
-#define MIN_JPROBES_STACK_SIZE(ADDR) \
- ((((ADDR) + MAX_JPROBES_STACK_SIZE) > MAX_JPROBES_STACK_ADDR) \
- ? MAX_JPROBES_STACK_ADDR - (ADDR) \
- : MAX_JPROBES_STACK_SIZE)
-
-
#define SKIP_DELAYSLOT 0x0001
/* per-cpu kprobe control block */
unsigned long kprobe_old_SR;
unsigned long kprobe_saved_SR;
unsigned long kprobe_saved_epc;
- unsigned long jprobe_saved_sp;
- struct pt_regs jprobe_saved_regs;
/* Per-thread fields, used while emulating branches */
unsigned long flags;
unsigned long target_epc;
- u8 jprobes_stack[MAX_JPROBES_STACK_SIZE];
struct prev_kprobe prev_kprobe;
};
preempt_enable_no_resched();
}
return 1;
- } else {
- if (addr->word != breakpoint_insn.word) {
- /*
- * The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate
- */
- ret = 1;
- goto no_kprobe;
- }
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs))
- goto ss_probe;
+ } else if (addr->word != breakpoint_insn.word) {
+ /*
+ * The breakpoint instruction was removed by
+ * another cpu right after we hit, no further
+ * handling of this interrupt is appropriate
+ */
+ ret = 1;
}
goto no_kprobe;
}
if (p->pre_handler && p->pre_handler(p, regs)) {
/* handler has already set things up, so skip ss setup */
+ reset_current_kprobe();
+ preempt_enable_no_resched();
return 1;
}
-ss_probe:
prepare_singlestep(p, regs, kcb);
if (kcb->flags & SKIP_DELAYSLOT) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
return ret;
}
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_sp = regs->regs[29];
-
- memcpy(kcb->jprobes_stack, (void *)kcb->jprobe_saved_sp,
- MIN_JPROBES_STACK_SIZE(kcb->jprobe_saved_sp));
-
- regs->cp0_epc = (unsigned long)(jp->entry);
-
- return 1;
-}
-
-/* Defined in the inline asm below. */
-void jprobe_return_end(void);
-
-void __kprobes jprobe_return(void)
-{
- /* Assembler quirk necessitates this '0,code' business. */
- asm volatile(
- "break 0,%0\n\t"
- ".globl jprobe_return_end\n"
- "jprobe_return_end:\n"
- : : "n" (BRK_KPROBE_BP) : "memory");
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (regs->cp0_epc >= (unsigned long)jprobe_return &&
- regs->cp0_epc <= (unsigned long)jprobe_return_end) {
- *regs = kcb->jprobe_saved_regs;
- memcpy((void *)kcb->jprobe_saved_sp, kcb->jprobes_stack,
- MIN_JPROBES_STACK_SIZE(kcb->jprobe_saved_sp));
- preempt_enable_no_resched();
-
- return 1;
- }
- return 0;
-}
-
/*
* Function return probe trampoline:
* - init_kprobes() establishes a probepoint here
kretprobe_assert(ri, orig_ret_address, trampoline_address);
instruction_pointer(regs) = orig_ret_address;
- reset_current_kprobe();
kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
#include <asm/reg.h>
#include <asm/debug.h>
+struct perf_event_attr;
struct perf_event;
struct pmu;
struct perf_sample_data;
extern int hw_breakpoint_slots(int type);
extern int arch_bp_generic_fields(int type, int *gen_bp_type);
-extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
-extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
+extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
int arch_install_hw_breakpoint(struct perf_event *bp);
struct kprobe_ctlblk {
unsigned long kprobe_status;
unsigned long kprobe_saved_msr;
- struct pt_regs jprobe_saved_regs;
struct prev_kprobe prev_kprobe;
};
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
extern int kprobe_handler(struct pt_regs *regs);
extern int kprobe_post_handler(struct pt_regs *regs);
-#ifdef CONFIG_KPROBES_ON_FTRACE
-extern int __is_active_jprobe(unsigned long addr);
-extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb);
-#else
-static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- return 0;
-}
-#endif
#else
static inline int kprobe_handler(struct pt_regs *regs) { return 0; }
static inline int kprobe_post_handler(struct pt_regs *regs) { return 0; }
/*
* Check for virtual address in kernel space.
*/
-int arch_check_bp_in_kernelspace(struct perf_event *bp)
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-
- return is_kernel_addr(info->address);
+ return is_kernel_addr(hw->address);
}
int arch_bp_generic_fields(int type, int *gen_bp_type)
/*
* Validate the arch-specific HW Breakpoint register settings
*/
-int arch_validate_hwbkpt_settings(struct perf_event *bp)
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
int ret = -EINVAL, length_max;
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
if (!bp)
return ret;
- info->type = HW_BRK_TYPE_TRANSLATE;
- if (bp->attr.bp_type & HW_BREAKPOINT_R)
- info->type |= HW_BRK_TYPE_READ;
- if (bp->attr.bp_type & HW_BREAKPOINT_W)
- info->type |= HW_BRK_TYPE_WRITE;
- if (info->type == HW_BRK_TYPE_TRANSLATE)
+ hw->type = HW_BRK_TYPE_TRANSLATE;
+ if (attr->bp_type & HW_BREAKPOINT_R)
+ hw->type |= HW_BRK_TYPE_READ;
+ if (attr->bp_type & HW_BREAKPOINT_W)
+ hw->type |= HW_BRK_TYPE_WRITE;
+ if (hw->type == HW_BRK_TYPE_TRANSLATE)
/* must set alteast read or write */
return ret;
- if (!(bp->attr.exclude_user))
- info->type |= HW_BRK_TYPE_USER;
- if (!(bp->attr.exclude_kernel))
- info->type |= HW_BRK_TYPE_KERNEL;
- if (!(bp->attr.exclude_hv))
- info->type |= HW_BRK_TYPE_HYP;
- info->address = bp->attr.bp_addr;
- info->len = bp->attr.bp_len;
+ if (!attr->exclude_user)
+ hw->type |= HW_BRK_TYPE_USER;
+ if (!attr->exclude_kernel)
+ hw->type |= HW_BRK_TYPE_KERNEL;
+ if (!attr->exclude_hv)
+ hw->type |= HW_BRK_TYPE_HYP;
+ hw->address = attr->bp_addr;
+ hw->len = attr->bp_len;
/*
* Since breakpoint length can be a maximum of HW_BREAKPOINT_LEN(8)
if (cpu_has_feature(CPU_FTR_DAWR)) {
length_max = 512 ; /* 64 doublewords */
/* DAWR region can't cross 512 boundary */
- if ((bp->attr.bp_addr >> 9) !=
- ((bp->attr.bp_addr + bp->attr.bp_len - 1) >> 9))
+ if ((attr->bp_addr >> 9) !=
+ ((attr->bp_addr + attr->bp_len - 1) >> 9))
return -EINVAL;
}
- if (info->len >
- (length_max - (info->address & HW_BREAKPOINT_ALIGN)))
+ if (hw->len >
+ (length_max - (hw->address & HW_BREAKPOINT_ALIGN)))
return -EINVAL;
return 0;
}
#include <linux/preempt.h>
#include <linux/ftrace.h>
-/*
- * This is called from ftrace code after invoking registered handlers to
- * disambiguate regs->nip changes done by jprobes and livepatch. We check if
- * there is an active jprobe at the provided address (mcount location).
- */
-int __is_active_jprobe(unsigned long addr)
-{
- if (!preemptible()) {
- struct kprobe *p = raw_cpu_read(current_kprobe);
- return (p && (unsigned long)p->addr == addr) ? 1 : 0;
- }
-
- return 0;
-}
-
-static nokprobe_inline
-int __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb, unsigned long orig_nip)
-{
- /*
- * Emulate singlestep (and also recover regs->nip)
- * as if there is a nop
- */
- regs->nip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
- if (unlikely(p->post_handler)) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- p->post_handler(p, regs, 0);
- }
- __this_cpu_write(current_kprobe, NULL);
- if (orig_nip)
- regs->nip = orig_nip;
- return 1;
-}
-
-int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- if (kprobe_ftrace(p))
- return __skip_singlestep(p, regs, kcb, 0);
- else
- return 0;
-}
-NOKPROBE_SYMBOL(skip_singlestep);
-
/* Ftrace callback handler for kprobes */
void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
struct ftrace_ops *ops, struct pt_regs *regs)
struct kprobe *p;
struct kprobe_ctlblk *kcb;
- preempt_disable();
-
p = get_kprobe((kprobe_opcode_t *)nip);
if (unlikely(!p) || kprobe_disabled(p))
- goto end;
+ return;
kcb = get_kprobe_ctlblk();
if (kprobe_running()) {
kprobes_inc_nmissed_count(p);
} else {
- unsigned long orig_nip = regs->nip;
-
/*
* On powerpc, NIP is *before* this instruction for the
* pre handler
__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- if (!p->pre_handler || !p->pre_handler(p, regs))
- __skip_singlestep(p, regs, kcb, orig_nip);
- else {
+ if (!p->pre_handler || !p->pre_handler(p, regs)) {
/*
- * If pre_handler returns !0, it sets regs->nip and
- * resets current kprobe. In this case, we should not
- * re-enable preemption.
+ * Emulate singlestep (and also recover regs->nip)
+ * as if there is a nop
*/
- return;
+ regs->nip += MCOUNT_INSN_SIZE;
+ if (unlikely(p->post_handler)) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
}
+ /*
+ * If pre_handler returns !0, it changes regs->nip. We have to
+ * skip emulating post_handler.
+ */
+ __this_cpu_write(current_kprobe, NULL);
}
-end:
- preempt_enable_no_resched();
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);
}
prepare_singlestep(p, regs);
return 1;
- } else {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /* If trap variant, then it belongs not to us */
- kprobe_opcode_t cur_insn = *addr;
- if (is_trap(cur_insn))
- goto no_kprobe;
- /* The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate
- */
- ret = 1;
+ } else if (*addr != BREAKPOINT_INSTRUCTION) {
+ /* If trap variant, then it belongs not to us */
+ kprobe_opcode_t cur_insn = *addr;
+
+ if (is_trap(cur_insn))
goto no_kprobe;
- }
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- if (!skip_singlestep(p, regs, kcb))
- goto ss_probe;
- ret = 1;
- }
+ /* The breakpoint instruction was removed by
+ * another cpu right after we hit, no further
+ * handling of this interrupt is appropriate
+ */
+ ret = 1;
}
goto no_kprobe;
}
*/
kprobe_opcode_t cur_insn = *addr;
if (is_trap(cur_insn))
- goto no_kprobe;
+ goto no_kprobe;
/*
* The breakpoint instruction was removed right
* after we hit it. Another cpu has removed
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
set_current_kprobe(p, regs, kcb);
- if (p->pre_handler && p->pre_handler(p, regs))
- /* handler has already set things up, so skip ss setup */
+ if (p->pre_handler && p->pre_handler(p, regs)) {
+ /* handler changed execution path, so skip ss setup */
+ reset_current_kprobe();
+ preempt_enable_no_resched();
return 1;
+ }
-ss_probe:
if (p->ainsn.boostable >= 0) {
ret = try_to_emulate(p, regs);
}
NOKPROBE_SYMBOL(arch_deref_entry_point);
-int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
-
- /* setup return addr to the jprobe handler routine */
- regs->nip = arch_deref_entry_point(jp->entry);
-#ifdef PPC64_ELF_ABI_v2
- regs->gpr[12] = (unsigned long)jp->entry;
-#elif defined(PPC64_ELF_ABI_v1)
- regs->gpr[2] = (unsigned long)(((func_descr_t *)jp->entry)->toc);
-#endif
-
- /*
- * jprobes use jprobe_return() which skips the normal return
- * path of the function, and this messes up the accounting of the
- * function graph tracer.
- *
- * Pause function graph tracing while performing the jprobe function.
- */
- pause_graph_tracing();
-
- return 1;
-}
-NOKPROBE_SYMBOL(setjmp_pre_handler);
-
-void __used jprobe_return(void)
-{
- asm volatile("jprobe_return_trap:\n"
- "trap\n"
- ::: "memory");
-}
-NOKPROBE_SYMBOL(jprobe_return);
-
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (regs->nip != ppc_kallsyms_lookup_name("jprobe_return_trap")) {
- pr_debug("longjmp_break_handler NIP (0x%lx) does not match jprobe_return_trap (0x%lx)\n",
- regs->nip, ppc_kallsyms_lookup_name("jprobe_return_trap"));
- return 0;
- }
-
- memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
- /* It's OK to start function graph tracing again */
- unpause_graph_tracing();
- preempt_enable_no_resched();
- return 1;
-}
-NOKPROBE_SYMBOL(longjmp_break_handler);
-
static struct kprobe trampoline_p = {
.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
.pre_handler = trampoline_probe_handler
bl ftrace_stub
nop
- /* Load the possibly modified NIP */
- ld r15, _NIP(r1)
-
+ /* Load ctr with the possibly modified NIP */
+ ld r3, _NIP(r1)
+ mtctr r3
#ifdef CONFIG_LIVEPATCH
- cmpd r14, r15 /* has NIP been altered? */
+ cmpd r14, r3 /* has NIP been altered? */
#endif
-#if defined(CONFIG_LIVEPATCH) && defined(CONFIG_KPROBES_ON_FTRACE)
- /* NIP has not been altered, skip over further checks */
- beq 1f
-
- /* Check if there is an active jprobe on us */
- subi r3, r14, 4
- bl __is_active_jprobe
- nop
-
- /*
- * If r3 == 1, then this is a kprobe/jprobe.
- * else, this is livepatched function.
- *
- * The conditional branch for livepatch_handler below will use the
- * result of this comparison. For kprobe/jprobe, we just need to branch to
- * the new NIP, not call livepatch_handler. The branch below is bne, so we
- * want CR0[EQ] to be true if this is a kprobe/jprobe. Which means we want
- * CR0[EQ] = (r3 == 1).
- */
- cmpdi r3, 1
-1:
-#endif
-
- /* Load CTR with the possibly modified NIP */
- mtctr r15
-
/* Restore gprs */
REST_GPR(0,r1)
REST_10GPRS(2,r1)
addi r1, r1, SWITCH_FRAME_SIZE
#ifdef CONFIG_LIVEPATCH
- /*
- * Based on the cmpd or cmpdi above, if the NIP was altered and we're
- * not on a kprobe/jprobe, then handle livepatch.
- */
+ /* Based on the cmpd above, if the NIP was altered handle livepatch */
bne- livepatch_handler
#endif
}
/*
- * Add a event to the PMU.
+ * Add an event to the PMU.
* If all events are not already frozen, then we disable and
* re-enable the PMU in order to get hw_perf_enable to do the
* actual work of reconfiguring the PMU.
}
/*
- * Remove a event from the PMU.
+ * Remove an event from the PMU.
*/
static void power_pmu_del(struct perf_event *event, int ef_flags)
{
/*
* Return 1 if we might be able to put event on a limited PMC,
* or 0 if not.
- * A event can only go on a limited PMC if it counts something
+ * An event can only go on a limited PMC if it counts something
* that a limited PMC can count, doesn't require interrupts, and
* doesn't exclude any processor mode.
*/
unsigned long kprobe_saved_imask;
unsigned long kprobe_saved_ctl[3];
struct prev_kprobe prev_kprobe;
- struct pt_regs jprobe_saved_regs;
- kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
};
void arch_remove_kprobe(struct kprobe *p);
* If we have no pre-handler or it returned 0, we
* continue with single stepping. If we have a
* pre-handler and it returned non-zero, it prepped
- * for calling the break_handler below on re-entry
- * for jprobe processing, so get out doing nothing
- * more here.
+ * for changing execution path, so get out doing
+ * nothing more here.
*/
push_kprobe(kcb, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- if (p->pre_handler && p->pre_handler(p, regs))
+ if (p->pre_handler && p->pre_handler(p, regs)) {
+ pop_kprobe(kcb);
+ preempt_enable_no_resched();
return 1;
+ }
kcb->kprobe_status = KPROBE_HIT_SS;
}
enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn);
return 1;
- } else if (kprobe_running()) {
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- /*
- * Continuation after the jprobe completed and
- * caused the jprobe_return trap. The jprobe
- * break_handler "returns" to the original
- * function that still has the kprobe breakpoint
- * installed. We continue with single stepping.
- */
- kcb->kprobe_status = KPROBE_HIT_SS;
- enable_singlestep(kcb, regs,
- (unsigned long) p->ainsn.insn);
- return 1;
- } /* else:
- * No kprobe at this address and the current kprobe
- * has no break handler (no jprobe!). The kernel just
- * exploded, let the standard trap handler pick up the
- * pieces.
- */
} /* else:
* No kprobe at this address and no active kprobe. The trap has
* not been caused by a kprobe breakpoint. The race of breakpoint
regs->psw.addr = orig_ret_address;
- pop_kprobe(get_kprobe_ctlblk());
kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
}
NOKPROBE_SYMBOL(kprobe_exceptions_notify);
-int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long stack;
-
- memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
-
- /* setup return addr to the jprobe handler routine */
- regs->psw.addr = (unsigned long) jp->entry;
- regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
-
- /* r15 is the stack pointer */
- stack = (unsigned long) regs->gprs[15];
-
- memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack));
-
- /*
- * jprobes use jprobe_return() which skips the normal return
- * path of the function, and this messes up the accounting of the
- * function graph tracer to get messed up.
- *
- * Pause function graph tracing while performing the jprobe function.
- */
- pause_graph_tracing();
- return 1;
-}
-NOKPROBE_SYMBOL(setjmp_pre_handler);
-
-void jprobe_return(void)
-{
- asm volatile(".word 0x0002");
-}
-NOKPROBE_SYMBOL(jprobe_return);
-
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long stack;
-
- /* It's OK to start function graph tracing again */
- unpause_graph_tracing();
-
- stack = (unsigned long) kcb->jprobe_saved_regs.gprs[15];
-
- /* Put the regs back */
- memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
- /* put the stack back */
- memcpy((void *) stack, kcb->jprobes_stack, MIN_STACK_SIZE(stack));
- preempt_enable_no_resched();
- return 1;
-}
-NOKPROBE_SYMBOL(longjmp_break_handler);
-
static struct kprobe trampoline = {
.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
.pre_handler = trampoline_probe_handler
#include <linux/types.h>
struct arch_hw_breakpoint {
- char *name; /* Contains name of the symbol to set bkpt */
unsigned long address;
u16 len;
u16 type;
struct clk *clk; /* optional interface clock / MSTP bit */
};
+struct perf_event_attr;
struct perf_event;
struct task_struct;
struct pmu;
}
/* arch/sh/kernel/hw_breakpoint.c */
-extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
-extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
+extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
void arch_remove_kprobe(struct kprobe *);
void kretprobe_trampoline(void);
-void jprobe_return_end(void);
/* Architecture specific copy of original instruction*/
struct arch_specific_insn {
/* per-cpu kprobe control block */
struct kprobe_ctlblk {
unsigned long kprobe_status;
- unsigned long jprobe_saved_r15;
- struct pt_regs jprobe_saved_regs;
- kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
struct prev_kprobe prev_kprobe;
};
/*
* Check for virtual address in kernel space.
*/
-int arch_check_bp_in_kernelspace(struct perf_event *bp)
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
{
unsigned int len;
unsigned long va;
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
- va = info->address;
- len = get_hbp_len(info->len);
+ va = hw->address;
+ len = get_hbp_len(hw->len);
return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
}
return 0;
}
-static int arch_build_bp_info(struct perf_event *bp)
+static int arch_build_bp_info(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-
- info->address = bp->attr.bp_addr;
+ hw->address = attr->bp_addr;
/* Len */
- switch (bp->attr.bp_len) {
+ switch (attr->bp_len) {
case HW_BREAKPOINT_LEN_1:
- info->len = SH_BREAKPOINT_LEN_1;
+ hw->len = SH_BREAKPOINT_LEN_1;
break;
case HW_BREAKPOINT_LEN_2:
- info->len = SH_BREAKPOINT_LEN_2;
+ hw->len = SH_BREAKPOINT_LEN_2;
break;
case HW_BREAKPOINT_LEN_4:
- info->len = SH_BREAKPOINT_LEN_4;
+ hw->len = SH_BREAKPOINT_LEN_4;
break;
case HW_BREAKPOINT_LEN_8:
- info->len = SH_BREAKPOINT_LEN_8;
+ hw->len = SH_BREAKPOINT_LEN_8;
break;
default:
return -EINVAL;
}
/* Type */
- switch (bp->attr.bp_type) {
+ switch (attr->bp_type) {
case HW_BREAKPOINT_R:
- info->type = SH_BREAKPOINT_READ;
+ hw->type = SH_BREAKPOINT_READ;
break;
case HW_BREAKPOINT_W:
- info->type = SH_BREAKPOINT_WRITE;
+ hw->type = SH_BREAKPOINT_WRITE;
break;
case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
- info->type = SH_BREAKPOINT_RW;
+ hw->type = SH_BREAKPOINT_RW;
break;
default:
return -EINVAL;
/*
* Validate the arch-specific HW Breakpoint register settings
*/
-int arch_validate_hwbkpt_settings(struct perf_event *bp)
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
unsigned int align;
int ret;
- ret = arch_build_bp_info(bp);
+ ret = arch_build_bp_info(bp, attr, hw);
if (ret)
return ret;
ret = -EINVAL;
- switch (info->len) {
+ switch (hw->len) {
case SH_BREAKPOINT_LEN_1:
align = 0;
break;
return ret;
}
- /*
- * For kernel-addresses, either the address or symbol name can be
- * specified.
- */
- if (info->name)
- info->address = (unsigned long)kallsyms_lookup_name(info->name);
-
/*
* Check that the low-order bits of the address are appropriate
* for the alignment implied by len.
*/
- if (info->address & align)
+ if (hw->address & align)
return -EINVAL;
return 0;
perf_bp_event(bp, args->regs);
/* Deliver the signal to userspace */
- if (!arch_check_bp_in_kernelspace(bp)) {
+ if (!arch_check_bp_in_kernelspace(&bp->hw.info)) {
force_sig_fault(SIGTRAP, TRAP_HWBKPT,
(void __user *)NULL, current);
}
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_REENTER;
return 1;
- } else {
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- goto ss_probe;
- }
}
goto no_kprobe;
}
set_current_kprobe(p, regs, kcb);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- if (p->pre_handler && p->pre_handler(p, regs))
+ if (p->pre_handler && p->pre_handler(p, regs)) {
/* handler has already set things up, so skip ss setup */
+ reset_current_kprobe();
+ preempt_enable_no_resched();
return 1;
+ }
-ss_probe:
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
regs->pc = orig_ret_address;
kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
-
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
if (post_kprobe_handler(args->regs))
ret = NOTIFY_STOP;
} else {
- if (kprobe_handler(args->regs)) {
+ if (kprobe_handler(args->regs))
ret = NOTIFY_STOP;
- } else {
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler &&
- p->break_handler(p, args->regs))
- ret = NOTIFY_STOP;
- }
}
}
}
return ret;
}
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- unsigned long addr;
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_r15 = regs->regs[15];
- addr = kcb->jprobe_saved_r15;
-
- /*
- * TBD: As Linus pointed out, gcc assumes that the callee
- * owns the argument space and could overwrite it, e.g.
- * tailcall optimization. So, to be absolutely safe
- * we also save and restore enough stack bytes to cover
- * the argument area.
- */
- memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr,
- MIN_STACK_SIZE(addr));
-
- regs->pc = (unsigned long)(jp->entry);
-
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- asm volatile ("trapa #0x3a\n\t" "jprobe_return_end:\n\t" "nop\n\t");
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long stack_addr = kcb->jprobe_saved_r15;
- u8 *addr = (u8 *)regs->pc;
-
- if ((addr >= (u8 *)jprobe_return) &&
- (addr <= (u8 *)jprobe_return_end)) {
- *regs = kcb->jprobe_saved_regs;
-
- memcpy((kprobe_opcode_t *)stack_addr, kcb->jprobes_stack,
- MIN_STACK_SIZE(stack_addr));
-
- kcb->kprobe_status = KPROBE_HIT_SS;
- preempt_enable_no_resched();
- return 1;
- }
-
- return 0;
-}
-
static struct kprobe trampoline_p = {
.addr = (kprobe_opcode_t *)&kretprobe_trampoline,
.pre_handler = trampoline_probe_handler
unsigned long kprobe_status;
unsigned long kprobe_orig_tnpc;
unsigned long kprobe_orig_tstate_pil;
- struct pt_regs jprobe_saved_regs;
struct prev_kprobe prev_kprobe;
};
kcb->kprobe_status = KPROBE_REENTER;
prepare_singlestep(p, regs, kcb);
return 1;
- } else {
- if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) {
+ } else if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) {
/* The breakpoint instruction was removed by
* another cpu right after we hit, no further
* handling of this interrupt is appropriate
*/
- ret = 1;
- goto no_kprobe;
- }
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs))
- goto ss_probe;
+ ret = 1;
}
goto no_kprobe;
}
set_current_kprobe(p, regs, kcb);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- if (p->pre_handler && p->pre_handler(p, regs))
+ if (p->pre_handler && p->pre_handler(p, regs)) {
+ reset_current_kprobe();
+ preempt_enable_no_resched();
return 1;
+ }
-ss_probe:
prepare_singlestep(p, regs, kcb);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
exception_exit(prev_state);
}
-/* Jprobes support. */
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- memcpy(&(kcb->jprobe_saved_regs), regs, sizeof(*regs));
-
- regs->tpc = (unsigned long) jp->entry;
- regs->tnpc = ((unsigned long) jp->entry) + 0x4UL;
- regs->tstate |= TSTATE_PIL;
-
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- register unsigned long orig_fp asm("g1");
-
- orig_fp = kcb->jprobe_saved_regs.u_regs[UREG_FP];
- __asm__ __volatile__("\n"
-"1: cmp %%sp, %0\n\t"
- "blu,a,pt %%xcc, 1b\n\t"
- " restore\n\t"
- ".globl jprobe_return_trap_instruction\n"
-"jprobe_return_trap_instruction:\n\t"
- "ta 0x70"
- : /* no outputs */
- : "r" (orig_fp));
-}
-
-extern void jprobe_return_trap_instruction(void);
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- u32 *addr = (u32 *) regs->tpc;
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (addr == (u32 *) jprobe_return_trap_instruction) {
- memcpy(regs, &(kcb->jprobe_saved_regs), sizeof(*regs));
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-
/* The value stored in the return address register is actually 2
* instructions before where the callee will return to.
* Sequences usually look something like this
regs->tpc = orig_ret_address;
regs->tnpc = orig_ret_address + 4;
- reset_current_kprobe();
kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
void intel_pmu_lbr_reset(void)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
if (!x86_pmu.lbr_nr)
return;
intel_pmu_lbr_reset_32();
else
intel_pmu_lbr_reset_64();
+
+ cpuc->last_task_ctx = NULL;
+ cpuc->last_log_id = 0;
}
/*
static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
int i;
unsigned lbr_idx, mask;
u64 tos;
return;
}
- mask = x86_pmu.lbr_nr - 1;
tos = task_ctx->tos;
- for (i = 0; i < tos; i++) {
+ /*
+ * Does not restore the LBR registers, if
+ * - No one else touched them, and
+ * - Did not enter C6
+ */
+ if ((task_ctx == cpuc->last_task_ctx) &&
+ (task_ctx->log_id == cpuc->last_log_id) &&
+ rdlbr_from(tos)) {
+ task_ctx->lbr_stack_state = LBR_NONE;
+ return;
+ }
+
+ mask = x86_pmu.lbr_nr - 1;
+ for (i = 0; i < task_ctx->valid_lbrs; i++) {
lbr_idx = (tos - i) & mask;
wrlbr_from(lbr_idx, task_ctx->lbr_from[i]);
wrlbr_to (lbr_idx, task_ctx->lbr_to[i]);
if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
wrmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
}
+
+ for (; i < x86_pmu.lbr_nr; i++) {
+ lbr_idx = (tos - i) & mask;
+ wrlbr_from(lbr_idx, 0);
+ wrlbr_to(lbr_idx, 0);
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
+ wrmsrl(MSR_LBR_INFO_0 + lbr_idx, 0);
+ }
+
wrmsrl(x86_pmu.lbr_tos, tos);
task_ctx->lbr_stack_state = LBR_NONE;
}
static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
unsigned lbr_idx, mask;
- u64 tos;
+ u64 tos, from;
int i;
if (task_ctx->lbr_callstack_users == 0) {
mask = x86_pmu.lbr_nr - 1;
tos = intel_pmu_lbr_tos();
- for (i = 0; i < tos; i++) {
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
lbr_idx = (tos - i) & mask;
- task_ctx->lbr_from[i] = rdlbr_from(lbr_idx);
+ from = rdlbr_from(lbr_idx);
+ if (!from)
+ break;
+ task_ctx->lbr_from[i] = from;
task_ctx->lbr_to[i] = rdlbr_to(lbr_idx);
if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
rdmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
}
+ task_ctx->valid_lbrs = i;
task_ctx->tos = tos;
task_ctx->lbr_stack_state = LBR_VALID;
+
+ cpuc->last_task_ctx = task_ctx;
+ cpuc->last_log_id = ++task_ctx->log_id;
}
void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in)
*/
static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
{
- bool need_info = false;
+ bool need_info = false, call_stack = false;
unsigned long mask = x86_pmu.lbr_nr - 1;
int lbr_format = x86_pmu.intel_cap.lbr_format;
u64 tos = intel_pmu_lbr_tos();
if (cpuc->lbr_sel) {
need_info = !(cpuc->lbr_sel->config & LBR_NO_INFO);
if (cpuc->lbr_sel->config & LBR_CALL_STACK)
- num = tos;
+ call_stack = true;
}
for (i = 0; i < num; i++) {
from = rdlbr_from(lbr_idx);
to = rdlbr_to(lbr_idx);
+ /*
+ * Read LBR call stack entries
+ * until invalid entry (0s) is detected.
+ */
+ if (call_stack && !from)
+ break;
+
if (lbr_format == LBR_FORMAT_INFO && need_info) {
u64 info;
unsigned core_id; /* per-core: core id */
};
+struct x86_perf_task_context;
#define MAX_LBR_ENTRIES 32
enum {
struct perf_branch_entry lbr_entries[MAX_LBR_ENTRIES];
struct er_account *lbr_sel;
u64 br_sel;
+ struct x86_perf_task_context *last_task_ctx;
+ int last_log_id;
/*
* Intel host/guest exclude bits
u64 lbr_to[MAX_LBR_ENTRIES];
u64 lbr_info[MAX_LBR_ENTRIES];
int tos;
+ int valid_lbrs;
int lbr_callstack_users;
int lbr_stack_state;
+ int log_id;
};
#define x86_add_quirk(func_) \
return HBP_NUM;
}
+struct perf_event_attr;
struct perf_event;
struct pmu;
-extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
-extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
+extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
* boostable = true: This instruction has been boosted: we have
* added a relative jump after the instruction copy in insn,
* so no single-step and fixup are needed (unless there's
- * a post_handler or break_handler).
+ * a post_handler).
*/
bool boostable;
bool if_modifier;
unsigned long kprobe_status;
unsigned long kprobe_old_flags;
unsigned long kprobe_saved_flags;
- unsigned long *jprobe_saved_sp;
- struct pt_regs jprobe_saved_regs;
- kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
struct prev_kprobe prev_kprobe;
};
set_dr_addr_mask(0, i);
}
-/*
- * Check for virtual address in kernel space.
- */
-int arch_check_bp_in_kernelspace(struct perf_event *bp)
+static int arch_bp_generic_len(int x86_len)
{
- unsigned int len;
- unsigned long va;
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-
- va = info->address;
- len = bp->attr.bp_len;
-
- /*
- * We don't need to worry about va + len - 1 overflowing:
- * we already require that va is aligned to a multiple of len.
- */
- return (va >= TASK_SIZE_MAX) || ((va + len - 1) >= TASK_SIZE_MAX);
+ switch (x86_len) {
+ case X86_BREAKPOINT_LEN_1:
+ return HW_BREAKPOINT_LEN_1;
+ case X86_BREAKPOINT_LEN_2:
+ return HW_BREAKPOINT_LEN_2;
+ case X86_BREAKPOINT_LEN_4:
+ return HW_BREAKPOINT_LEN_4;
+#ifdef CONFIG_X86_64
+ case X86_BREAKPOINT_LEN_8:
+ return HW_BREAKPOINT_LEN_8;
+#endif
+ default:
+ return -EINVAL;
+ }
}
int arch_bp_generic_fields(int x86_len, int x86_type,
int *gen_len, int *gen_type)
{
+ int len;
+
/* Type */
switch (x86_type) {
case X86_BREAKPOINT_EXECUTE:
}
/* Len */
- switch (x86_len) {
- case X86_BREAKPOINT_LEN_1:
- *gen_len = HW_BREAKPOINT_LEN_1;
- break;
- case X86_BREAKPOINT_LEN_2:
- *gen_len = HW_BREAKPOINT_LEN_2;
- break;
- case X86_BREAKPOINT_LEN_4:
- *gen_len = HW_BREAKPOINT_LEN_4;
- break;
-#ifdef CONFIG_X86_64
- case X86_BREAKPOINT_LEN_8:
- *gen_len = HW_BREAKPOINT_LEN_8;
- break;
-#endif
- default:
+ len = arch_bp_generic_len(x86_len);
+ if (len < 0)
return -EINVAL;
- }
+ *gen_len = len;
return 0;
}
-
-static int arch_build_bp_info(struct perf_event *bp)
+/*
+ * Check for virtual address in kernel space.
+ */
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ unsigned long va;
+ int len;
- info->address = bp->attr.bp_addr;
+ va = hw->address;
+ len = arch_bp_generic_len(hw->len);
+ WARN_ON_ONCE(len < 0);
+
+ /*
+ * We don't need to worry about va + len - 1 overflowing:
+ * we already require that va is aligned to a multiple of len.
+ */
+ return (va >= TASK_SIZE_MAX) || ((va + len - 1) >= TASK_SIZE_MAX);
+}
+
+static int arch_build_bp_info(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
+{
+ hw->address = attr->bp_addr;
+ hw->mask = 0;
/* Type */
- switch (bp->attr.bp_type) {
+ switch (attr->bp_type) {
case HW_BREAKPOINT_W:
- info->type = X86_BREAKPOINT_WRITE;
+ hw->type = X86_BREAKPOINT_WRITE;
break;
case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
- info->type = X86_BREAKPOINT_RW;
+ hw->type = X86_BREAKPOINT_RW;
break;
case HW_BREAKPOINT_X:
/*
* acceptable for kprobes. On non-kprobes kernels, we don't
* allow kernel breakpoints at all.
*/
- if (bp->attr.bp_addr >= TASK_SIZE_MAX) {
+ if (attr->bp_addr >= TASK_SIZE_MAX) {
#ifdef CONFIG_KPROBES
- if (within_kprobe_blacklist(bp->attr.bp_addr))
+ if (within_kprobe_blacklist(attr->bp_addr))
return -EINVAL;
#else
return -EINVAL;
#endif
}
- info->type = X86_BREAKPOINT_EXECUTE;
+ hw->type = X86_BREAKPOINT_EXECUTE;
/*
* x86 inst breakpoints need to have a specific undefined len.
* But we still need to check userspace is not trying to setup
* an unsupported length, to get a range breakpoint for example.
*/
- if (bp->attr.bp_len == sizeof(long)) {
- info->len = X86_BREAKPOINT_LEN_X;
+ if (attr->bp_len == sizeof(long)) {
+ hw->len = X86_BREAKPOINT_LEN_X;
return 0;
}
default:
}
/* Len */
- info->mask = 0;
-
- switch (bp->attr.bp_len) {
+ switch (attr->bp_len) {
case HW_BREAKPOINT_LEN_1:
- info->len = X86_BREAKPOINT_LEN_1;
+ hw->len = X86_BREAKPOINT_LEN_1;
break;
case HW_BREAKPOINT_LEN_2:
- info->len = X86_BREAKPOINT_LEN_2;
+ hw->len = X86_BREAKPOINT_LEN_2;
break;
case HW_BREAKPOINT_LEN_4:
- info->len = X86_BREAKPOINT_LEN_4;
+ hw->len = X86_BREAKPOINT_LEN_4;
break;
#ifdef CONFIG_X86_64
case HW_BREAKPOINT_LEN_8:
- info->len = X86_BREAKPOINT_LEN_8;
+ hw->len = X86_BREAKPOINT_LEN_8;
break;
#endif
default:
/* AMD range breakpoint */
- if (!is_power_of_2(bp->attr.bp_len))
+ if (!is_power_of_2(attr->bp_len))
return -EINVAL;
- if (bp->attr.bp_addr & (bp->attr.bp_len - 1))
+ if (attr->bp_addr & (attr->bp_len - 1))
return -EINVAL;
if (!boot_cpu_has(X86_FEATURE_BPEXT))
* breakpoints, then we'll have to check for kprobe-blacklisted
* addresses anywhere in the range.
*/
- info->mask = bp->attr.bp_len - 1;
- info->len = X86_BREAKPOINT_LEN_1;
+ hw->mask = attr->bp_len - 1;
+ hw->len = X86_BREAKPOINT_LEN_1;
}
return 0;
/*
* Validate the arch-specific HW Breakpoint register settings
*/
-int arch_validate_hwbkpt_settings(struct perf_event *bp)
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
unsigned int align;
int ret;
- ret = arch_build_bp_info(bp);
+ ret = arch_build_bp_info(bp, attr, hw);
if (ret)
return ret;
- switch (info->len) {
+ switch (hw->len) {
case X86_BREAKPOINT_LEN_1:
align = 0;
- if (info->mask)
- align = info->mask;
+ if (hw->mask)
+ align = hw->mask;
break;
case X86_BREAKPOINT_LEN_2:
align = 1;
* Check that the low-order bits of the address are appropriate
* for the alignment implied by len.
*/
- if (info->address & align)
+ if (hw->address & align)
return -EINVAL;
return 0;
}
#endif
-#ifdef CONFIG_KPROBES_ON_FTRACE
-extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb);
-#else
-static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- return 0;
-}
-#endif
#endif
#include "common.h"
-void jprobe_return_end(void);
-
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
- (u8 *) real;
if ((s64) (s32) newdisp != newdisp) {
pr_err("Kprobes error: new displacement does not fit into s32 (%llx)\n", newdisp);
- pr_err("\tSrc: %p, Dest: %p, old disp: %x\n",
- src, real, insn->displacement.value);
return 0;
}
disp = (u8 *) dest + insn_offset_displacement(insn);
* stepping.
*/
regs->ip = (unsigned long)p->ainsn.insn;
- preempt_enable_no_resched();
return;
}
#endif
* Raise a BUG or we'll continue in an endless reentering loop
* and eventually a stack overflow.
*/
- printk(KERN_WARNING "Unrecoverable kprobe detected at %p.\n",
- p->addr);
+ pr_err("Unrecoverable kprobe detected.\n");
dump_kprobe(p);
BUG();
default:
addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
/*
- * We don't want to be preempted for the entire
- * duration of kprobe processing. We conditionally
- * re-enable preemption at the end of this function,
- * and also in reenter_kprobe() and setup_singlestep().
+ * We don't want to be preempted for the entire duration of kprobe
+ * processing. Since int3 and debug trap disables irqs and we clear
+ * IF while singlestepping, it must be no preemptible.
*/
- preempt_disable();
kcb = get_kprobe_ctlblk();
p = get_kprobe(addr);
/*
* If we have no pre-handler or it returned 0, we
* continue with normal processing. If we have a
- * pre-handler and it returned non-zero, it prepped
- * for calling the break_handler below on re-entry
- * for jprobe processing, so get out doing nothing
- * more here.
+ * pre-handler and it returned non-zero, that means
+ * user handler setup registers to exit to another
+ * instruction, we must skip the single stepping.
*/
if (!p->pre_handler || !p->pre_handler(p, regs))
setup_singlestep(p, regs, kcb, 0);
+ else
+ reset_current_kprobe();
return 1;
}
} else if (*addr != BREAKPOINT_INSTRUCTION) {
* the original instruction.
*/
regs->ip = (unsigned long)addr;
- preempt_enable_no_resched();
return 1;
- } else if (kprobe_running()) {
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- if (!skip_singlestep(p, regs, kcb))
- setup_singlestep(p, regs, kcb, 0);
- return 1;
- }
} /* else: not a kprobe fault; let the kernel handle it */
- preempt_enable_no_resched();
return 0;
}
NOKPROBE_SYMBOL(kprobe_int3_handler);
}
reset_current_kprobe();
out:
- preempt_enable_no_resched();
-
/*
* if somebody else is singlestepping across a probe point, flags
* will have TF set, in which case, continue the remaining processing
restore_previous_kprobe(kcb);
else
reset_current_kprobe();
- preempt_enable_no_resched();
} else if (kcb->kprobe_status == KPROBE_HIT_ACTIVE ||
kcb->kprobe_status == KPROBE_HIT_SSDONE) {
/*
}
NOKPROBE_SYMBOL(kprobe_exceptions_notify);
-int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- unsigned long addr;
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_sp = stack_addr(regs);
- addr = (unsigned long)(kcb->jprobe_saved_sp);
-
- /*
- * As Linus pointed out, gcc assumes that the callee
- * owns the argument space and could overwrite it, e.g.
- * tailcall optimization. So, to be absolutely safe
- * we also save and restore enough stack bytes to cover
- * the argument area.
- * Use __memcpy() to avoid KASAN stack out-of-bounds reports as we copy
- * raw stack chunk with redzones:
- */
- __memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr));
- regs->ip = (unsigned long)(jp->entry);
-
- /*
- * jprobes use jprobe_return() which skips the normal return
- * path of the function, and this messes up the accounting of the
- * function graph tracer to get messed up.
- *
- * Pause function graph tracing while performing the jprobe function.
- */
- pause_graph_tracing();
- return 1;
-}
-NOKPROBE_SYMBOL(setjmp_pre_handler);
-
-void jprobe_return(void)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- /* Unpoison stack redzones in the frames we are going to jump over. */
- kasan_unpoison_stack_above_sp_to(kcb->jprobe_saved_sp);
-
- asm volatile (
-#ifdef CONFIG_X86_64
- " xchg %%rbx,%%rsp \n"
-#else
- " xchgl %%ebx,%%esp \n"
-#endif
- " int3 \n"
- " .globl jprobe_return_end\n"
- " jprobe_return_end: \n"
- " nop \n"::"b"
- (kcb->jprobe_saved_sp):"memory");
-}
-NOKPROBE_SYMBOL(jprobe_return);
-NOKPROBE_SYMBOL(jprobe_return_end);
-
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- u8 *addr = (u8 *) (regs->ip - 1);
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- void *saved_sp = kcb->jprobe_saved_sp;
-
- if ((addr > (u8 *) jprobe_return) &&
- (addr < (u8 *) jprobe_return_end)) {
- if (stack_addr(regs) != saved_sp) {
- struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
- printk(KERN_ERR
- "current sp %p does not match saved sp %p\n",
- stack_addr(regs), saved_sp);
- printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
- show_regs(saved_regs);
- printk(KERN_ERR "Current registers\n");
- show_regs(regs);
- BUG();
- }
- /* It's OK to start function graph tracing again */
- unpause_graph_tracing();
- *regs = kcb->jprobe_saved_regs;
- __memcpy(saved_sp, kcb->jprobes_stack, MIN_STACK_SIZE(saved_sp));
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-NOKPROBE_SYMBOL(longjmp_break_handler);
-
bool arch_within_kprobe_blacklist(unsigned long addr)
{
bool is_in_entry_trampoline_section = false;
#include "common.h"
-static nokprobe_inline
-void __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb, unsigned long orig_ip)
-{
- /*
- * Emulate singlestep (and also recover regs->ip)
- * as if there is a 5byte nop
- */
- regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
- if (unlikely(p->post_handler)) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- p->post_handler(p, regs, 0);
- }
- __this_cpu_write(current_kprobe, NULL);
- if (orig_ip)
- regs->ip = orig_ip;
-}
-
-int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- if (kprobe_ftrace(p)) {
- __skip_singlestep(p, regs, kcb, 0);
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-NOKPROBE_SYMBOL(skip_singlestep);
-
/* Ftrace callback handler for kprobes -- called under preepmt disabed */
void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct pt_regs *regs)
/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
regs->ip = ip + sizeof(kprobe_opcode_t);
- /* To emulate trap based kprobes, preempt_disable here */
- preempt_disable();
__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (!p->pre_handler || !p->pre_handler(p, regs)) {
- __skip_singlestep(p, regs, kcb, orig_ip);
- preempt_enable_no_resched();
+ /*
+ * Emulate singlestep (and also recover regs->ip)
+ * as if there is a 5byte nop
+ */
+ regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
+ if (unlikely(p->post_handler)) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
+ regs->ip = orig_ip;
}
/*
- * If pre_handler returns !0, it sets regs->ip and
- * resets current kprobe, and keep preempt count +1.
+ * If pre_handler returns !0, it changes regs->ip. We have to
+ * skip emulating post_handler.
*/
+ __this_cpu_write(current_kprobe, NULL);
}
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);
regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX;
if (!reenter)
reset_current_kprobe();
- preempt_enable_no_resched();
return 1;
}
return 0;
u16 type;
};
+struct perf_event_attr;
struct perf_event;
struct pt_regs;
struct task_struct;
int hw_breakpoint_slots(int type);
-int arch_check_bp_in_kernelspace(struct perf_event *bp);
-int arch_validate_hwbkpt_settings(struct perf_event *bp);
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
}
}
-int arch_check_bp_in_kernelspace(struct perf_event *bp)
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
{
unsigned int len;
unsigned long va;
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
- va = info->address;
- len = bp->attr.bp_len;
+ va = hw->address;
+ len = hw->len;
return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
}
/*
* Construct an arch_hw_breakpoint from a perf_event.
*/
-static int arch_build_bp_info(struct perf_event *bp)
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-
/* Type */
- switch (bp->attr.bp_type) {
+ switch (attr->bp_type) {
case HW_BREAKPOINT_X:
- info->type = XTENSA_BREAKPOINT_EXECUTE;
+ hw->type = XTENSA_BREAKPOINT_EXECUTE;
break;
case HW_BREAKPOINT_R:
- info->type = XTENSA_BREAKPOINT_LOAD;
+ hw->type = XTENSA_BREAKPOINT_LOAD;
break;
case HW_BREAKPOINT_W:
- info->type = XTENSA_BREAKPOINT_STORE;
+ hw->type = XTENSA_BREAKPOINT_STORE;
break;
case HW_BREAKPOINT_RW:
- info->type = XTENSA_BREAKPOINT_LOAD | XTENSA_BREAKPOINT_STORE;
+ hw->type = XTENSA_BREAKPOINT_LOAD | XTENSA_BREAKPOINT_STORE;
break;
default:
return -EINVAL;
}
/* Len */
- info->len = bp->attr.bp_len;
- if (info->len < 1 || info->len > 64 || !is_power_of_2(info->len))
+ hw->len = attr->bp_len;
+ if (hw->len < 1 || hw->len > 64 || !is_power_of_2(hw->len))
return -EINVAL;
/* Address */
- info->address = bp->attr.bp_addr;
- if (info->address & (info->len - 1))
+ hw->address = attr->bp_addr;
+ if (hw->address & (hw->len - 1))
return -EINVAL;
return 0;
}
-int arch_validate_hwbkpt_settings(struct perf_event *bp)
-{
- int ret;
-
- /* Build the arch_hw_breakpoint. */
- ret = arch_build_bp_info(bp);
- return ret;
-}
-
int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data)
{
struct kretprobe;
struct kretprobe_instance;
typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
-typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
unsigned long flags);
typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
*/
kprobe_fault_handler_t fault_handler;
- /*
- * ... called if breakpoint trap occurs in probe handler.
- * Return 1 if it handled break, otherwise kernel will see it.
- */
- kprobe_break_handler_t break_handler;
-
/* Saved opcode (which has been replaced with breakpoint) */
kprobe_opcode_t opcode;
return p->flags & KPROBE_FLAG_FTRACE;
}
-/*
- * Special probe type that uses setjmp-longjmp type tricks to resume
- * execution at a specified entry with a matching prototype corresponding
- * to the probed function - a trick to enable arguments to become
- * accessible seamlessly by probe handling logic.
- * Note:
- * Because of the way compilers allocate stack space for local variables
- * etc upfront, regardless of sub-scopes within a function, this mirroring
- * principle currently works only for probes placed on function entry points.
- */
-struct jprobe {
- struct kprobe kp;
- void *entry; /* probe handling code to jump to */
-};
-
-/* For backward compatibility with old code using JPROBE_ENTRY() */
-#define JPROBE_ENTRY(handler) (handler)
-
/*
* Function-return probe -
* Note:
void unregister_kprobe(struct kprobe *p);
int register_kprobes(struct kprobe **kps, int num);
void unregister_kprobes(struct kprobe **kps, int num);
-int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
-int longjmp_break_handler(struct kprobe *, struct pt_regs *);
-void jprobe_return(void);
unsigned long arch_deref_entry_point(void *);
int register_kretprobe(struct kretprobe *rp);
static inline void unregister_kprobes(struct kprobe **kps, int num)
{
}
-static inline void jprobe_return(void)
-{
-}
static inline int register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
return -ENOSYS;
}
#endif /* CONFIG_KPROBES */
-static inline int register_jprobe(struct jprobe *p)
-{
- return -ENOSYS;
-}
-static inline int register_jprobes(struct jprobe **jps, int num)
-{
- return -ENOSYS;
-}
-static inline void unregister_jprobe(struct jprobe *p)
-{
-}
-static inline void unregister_jprobes(struct jprobe **jps, int num)
-{
-}
static inline int disable_kretprobe(struct kretprobe *rp)
{
return disable_kprobe(&rp->kp);
{
return enable_kprobe(&rp->kp);
}
-static inline int disable_jprobe(struct jprobe *jp)
-{
- return -ENOSYS;
-}
-static inline int enable_jprobe(struct jprobe *jp)
-{
- return -ENOSYS;
-}
#ifndef CONFIG_KPROBES
static inline bool is_kprobe_insn_slot(unsigned long addr)
};
/**
- * enum perf_event_state - the states of a event
+ * enum perf_event_state - the states of an event:
*/
enum perf_event_state {
PERF_EVENT_STATE_DEAD = -4,
typeof(*event), group_node))
/*
- * Add a event from the lists for its context.
+ * Add an event from the lists for its context.
* Must be called with ctx->mutex and ctx->lock held.
*/
static void
}
/*
- * Remove a event from the lists for its context.
+ * Remove an event from the lists for its context.
* Must be called with ctx->mutex and ctx->lock held.
*/
static void
}
/*
- * Disable a event.
+ * Disable an event.
*
* If event->ctx is a cloned context, callers must make sure that
* every task struct that event->ctx->task could possibly point to
}
/*
- * Enable a event.
+ * Enable an event.
*
* If event->ctx is a cloned context, callers must make sure that
* every task struct that event->ctx->task could possibly point to
* events will refuse to restart because of rb::aux_mmap_count==0,
* see comments in perf_aux_output_begin().
*
- * Since this is happening on a event-local CPU, no trace is lost
+ * Since this is happening on an event-local CPU, no trace is lost
* while restarting.
*/
if (sd->restart)
int ret;
/*
- * Return end-of-file for a read on a event that is in
+ * Return end-of-file for a read on an event that is in
* error state (i.e. because it was pinned but it couldn't be
* scheduled on to the CPU at some point).
*/
}
EXPORT_SYMBOL_GPL(perf_event_update_userpage);
-static int perf_mmap_fault(struct vm_fault *vmf)
+static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
{
struct perf_event *event = vmf->vma->vm_file->private_data;
struct ring_buffer *rb;
- int ret = VM_FAULT_SIGBUS;
+ vm_fault_t ret = VM_FAULT_SIGBUS;
if (vmf->flags & FAULT_FLAG_MKWRITE) {
if (vmf->pgoff == 0)
}
/*
- * Allocate and initialize a event structure
+ * Allocate and initialize an event structure
*/
static struct perf_event *
perf_event_alloc(struct perf_event_attr *attr, int cpu,
}
/*
- * Inherit a event from parent task to child task.
+ * Inherit an event from parent task to child task.
*
* Returns:
* - valid pointer on success
mutex_unlock(&nr_bp_mutex);
}
-static int __modify_bp_slot(struct perf_event *bp, u64 old_type)
+static int __modify_bp_slot(struct perf_event *bp, u64 old_type, u64 new_type)
{
int err;
__release_bp_slot(bp, old_type);
- err = __reserve_bp_slot(bp, bp->attr.bp_type);
+ err = __reserve_bp_slot(bp, new_type);
if (err) {
/*
* Reserve the old_type slot back in case
return err;
}
-static int modify_bp_slot(struct perf_event *bp, u64 old_type)
+static int modify_bp_slot(struct perf_event *bp, u64 old_type, u64 new_type)
{
int ret;
mutex_lock(&nr_bp_mutex);
- ret = __modify_bp_slot(bp, old_type);
+ ret = __modify_bp_slot(bp, old_type, new_type);
mutex_unlock(&nr_bp_mutex);
return ret;
}
return 0;
}
-static int validate_hw_breakpoint(struct perf_event *bp)
+static int hw_breakpoint_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
{
- int ret;
+ int err;
- ret = arch_validate_hwbkpt_settings(bp);
- if (ret)
- return ret;
+ err = hw_breakpoint_arch_parse(bp, attr, hw);
+ if (err)
+ return err;
- if (arch_check_bp_in_kernelspace(bp)) {
- if (bp->attr.exclude_kernel)
+ if (arch_check_bp_in_kernelspace(hw)) {
+ if (attr->exclude_kernel)
return -EINVAL;
/*
* Don't let unprivileged users set a breakpoint in the trap
int register_perf_hw_breakpoint(struct perf_event *bp)
{
- int ret;
-
- ret = reserve_bp_slot(bp);
- if (ret)
- return ret;
+ struct arch_hw_breakpoint hw;
+ int err;
- ret = validate_hw_breakpoint(bp);
+ err = reserve_bp_slot(bp);
+ if (err)
+ return err;
- /* if arch_validate_hwbkpt_settings() fails then release bp slot */
- if (ret)
+ err = hw_breakpoint_parse(bp, &bp->attr, &hw);
+ if (err) {
release_bp_slot(bp);
+ return err;
+ }
- return ret;
+ bp->hw.info = hw;
+
+ return 0;
}
/**
}
EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
+static void hw_breakpoint_copy_attr(struct perf_event_attr *to,
+ struct perf_event_attr *from)
+{
+ to->bp_addr = from->bp_addr;
+ to->bp_type = from->bp_type;
+ to->bp_len = from->bp_len;
+ to->disabled = from->disabled;
+}
+
int
modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr,
bool check)
{
- u64 old_addr = bp->attr.bp_addr;
- u64 old_len = bp->attr.bp_len;
- int old_type = bp->attr.bp_type;
- bool modify = attr->bp_type != old_type;
- int err = 0;
+ struct arch_hw_breakpoint hw;
+ int err;
- bp->attr.bp_addr = attr->bp_addr;
- bp->attr.bp_type = attr->bp_type;
- bp->attr.bp_len = attr->bp_len;
+ err = hw_breakpoint_parse(bp, attr, &hw);
+ if (err)
+ return err;
- if (check && memcmp(&bp->attr, attr, sizeof(*attr)))
- return -EINVAL;
+ if (check) {
+ struct perf_event_attr old_attr;
- err = validate_hw_breakpoint(bp);
- if (!err && modify)
- err = modify_bp_slot(bp, old_type);
+ old_attr = bp->attr;
+ hw_breakpoint_copy_attr(&old_attr, attr);
+ if (memcmp(&old_attr, attr, sizeof(*attr)))
+ return -EINVAL;
+ }
- if (err) {
- bp->attr.bp_addr = old_addr;
- bp->attr.bp_type = old_type;
- bp->attr.bp_len = old_len;
- return err;
+ if (bp->attr.bp_type != attr->bp_type) {
+ err = modify_bp_slot(bp, bp->attr.bp_type, attr->bp_type);
+ if (err)
+ return err;
}
- bp->attr.disabled = attr->disabled;
+ hw_breakpoint_copy_attr(&bp->attr, attr);
+ bp->hw.info = hw;
+
return 0;
}
EXPORT_SYMBOL_GPL(uprobe_register);
/*
- * uprobe_apply - unregister a already registered probe.
+ * uprobe_apply - unregister an already registered probe.
* @inode: the file in which the probe has to be removed.
* @offset: offset from the start of the file.
* @uc: consumer which wants to add more or remove some breakpoints
}
/*
- * uprobe_unregister - unregister a already registered probe.
+ * uprobe_unregister - unregister an already registered probe.
* @inode: the file in which the probe has to be removed.
* @offset: offset from the start of the file.
* @uc: identify which probe if multiple probes are colocated.
/*
* Called with no locks held.
- * Called in context of a exiting or a exec-ing thread.
+ * Called in context of an exiting or an exec-ing thread.
*/
void uprobe_free_utask(struct task_struct *t)
{
if (should_fail(&fei_fault_attr, 1)) {
regs_set_return_value(regs, attr->retval);
override_function_with_return(regs);
- /* Kprobe specific fixup */
- reset_current_kprobe();
- preempt_enable_no_resched();
return 1;
}
(kprobe_disabled(p) || kprobes_all_disarmed))
return;
- /* Both of break_handler and post_handler are not supported. */
- if (p->break_handler || p->post_handler)
+ /* kprobes with post_handler can not be optimized */
+ if (p->post_handler)
return;
op = container_of(p, struct optimized_kprobe, kp);
* there is still a relative jump) and disabled.
*/
op = container_of(ap, struct optimized_kprobe, kp);
- if (unlikely(list_empty(&op->list)))
- printk(KERN_WARNING "Warning: found a stray unused "
- "aggrprobe@%p\n", ap->addr);
+ WARN_ON_ONCE(list_empty(&op->list));
/* Enable the probe again */
ap->flags &= ~KPROBE_FLAG_DISABLED;
/* Optimize it again (remove from op->list) */
ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
(unsigned long)p->addr, 0, 0);
if (ret) {
- pr_debug("Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret);
+ pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n",
+ p->addr, ret);
return ret;
}
ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
(unsigned long)p->addr, 1, 0);
- WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret);
+ WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n",
+ p->addr, ret);
return ret;
}
#else /* !CONFIG_KPROBES_ON_FTRACE */
}
NOKPROBE_SYMBOL(aggr_fault_handler);
-static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe *cur = __this_cpu_read(kprobe_instance);
- int ret = 0;
-
- if (cur && cur->break_handler) {
- if (cur->break_handler(cur, regs))
- ret = 1;
- }
- reset_kprobe_instance();
- return ret;
-}
-NOKPROBE_SYMBOL(aggr_break_handler);
-
/* Walks the list and increments nmissed count for multiprobe case */
void kprobes_inc_nmissed_count(struct kprobe *p)
{
}
NOKPROBE_SYMBOL(cleanup_rp_inst);
-/*
-* Add the new probe to ap->list. Fail if this is the
-* second jprobe at the address - two jprobes can't coexist
-*/
+/* Add the new probe to ap->list */
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
{
BUG_ON(kprobe_gone(ap) || kprobe_gone(p));
- if (p->break_handler || p->post_handler)
+ if (p->post_handler)
unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */
- if (p->break_handler) {
- if (ap->break_handler)
- return -EEXIST;
- list_add_tail_rcu(&p->list, &ap->list);
- ap->break_handler = aggr_break_handler;
- } else
- list_add_rcu(&p->list, &ap->list);
+ list_add_rcu(&p->list, &ap->list);
if (p->post_handler && !ap->post_handler)
ap->post_handler = aggr_post_handler;
/* We don't care the kprobe which has gone. */
if (p->post_handler && !kprobe_gone(p))
ap->post_handler = aggr_post_handler;
- if (p->break_handler && !kprobe_gone(p))
- ap->break_handler = aggr_break_handler;
INIT_LIST_HEAD(&ap->list);
INIT_HLIST_NODE(&ap->hlist);
goto disarmed;
else {
/* If disabling probe has special handlers, update aggrprobe */
- if (p->break_handler && !kprobe_gone(p))
- ap->break_handler = NULL;
if (p->post_handler && !kprobe_gone(p)) {
list_for_each_entry_rcu(list_p, &ap->list, list) {
if ((list_p != p) && (list_p->post_handler))
return (unsigned long)entry;
}
-#if 0
-int register_jprobes(struct jprobe **jps, int num)
-{
- int ret = 0, i;
-
- if (num <= 0)
- return -EINVAL;
-
- for (i = 0; i < num; i++) {
- ret = register_jprobe(jps[i]);
-
- if (ret < 0) {
- if (i > 0)
- unregister_jprobes(jps, i);
- break;
- }
- }
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(register_jprobes);
-
-int register_jprobe(struct jprobe *jp)
-{
- unsigned long addr, offset;
- struct kprobe *kp = &jp->kp;
-
- /*
- * Verify probepoint as well as the jprobe handler are
- * valid function entry points.
- */
- addr = arch_deref_entry_point(jp->entry);
-
- if (kallsyms_lookup_size_offset(addr, NULL, &offset) && offset == 0 &&
- kprobe_on_func_entry(kp->addr, kp->symbol_name, kp->offset)) {
- kp->pre_handler = setjmp_pre_handler;
- kp->break_handler = longjmp_break_handler;
- return register_kprobe(kp);
- }
-
- return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(register_jprobe);
-
-void unregister_jprobe(struct jprobe *jp)
-{
- unregister_jprobes(&jp, 1);
-}
-EXPORT_SYMBOL_GPL(unregister_jprobe);
-
-void unregister_jprobes(struct jprobe **jps, int num)
-{
- int i;
-
- if (num <= 0)
- return;
- mutex_lock(&kprobe_mutex);
- for (i = 0; i < num; i++)
- if (__unregister_kprobe_top(&jps[i]->kp) < 0)
- jps[i]->kp.addr = NULL;
- mutex_unlock(&kprobe_mutex);
-
- synchronize_sched();
- for (i = 0; i < num; i++) {
- if (jps[i]->kp.addr)
- __unregister_kprobe_bottom(&jps[i]->kp);
- }
-}
-EXPORT_SYMBOL_GPL(unregister_jprobes);
-#endif
-
#ifdef CONFIG_KRETPROBES
/*
* This kprobe pre_handler is registered with every kretprobe. When probe
rp->kp.pre_handler = pre_handler_kretprobe;
rp->kp.post_handler = NULL;
rp->kp.fault_handler = NULL;
- rp->kp.break_handler = NULL;
/* Pre-allocate memory for max kretprobe instances */
if (rp->maxactive <= 0) {
list_for_each_entry_rcu(kp, &p->list, list)
kp->flags |= KPROBE_FLAG_GONE;
p->post_handler = NULL;
- p->break_handler = NULL;
kill_optimized_kprobe(p);
}
/*
}
EXPORT_SYMBOL_GPL(enable_kprobe);
+/* Caller must NOT call this in usual path. This is only for critical case */
void dump_kprobe(struct kprobe *kp)
{
- printk(KERN_WARNING "Dumping kprobe:\n");
- printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n",
- kp->symbol_name, kp->addr, kp->offset);
+ pr_err("Dumping kprobe:\n");
+ pr_err("Name: %s\nOffset: %x\nAddress: %pS\n",
+ kp->symbol_name, kp->offset, kp->addr);
}
NOKPROBE_SYMBOL(dump_kprobe);
entry = arch_deref_entry_point((void *)*iter);
if (!kernel_text_address(entry) ||
- !kallsyms_lookup_size_offset(entry, &size, &offset)) {
- pr_err("Failed to find blacklist at %p\n",
- (void *)entry);
+ !kallsyms_lookup_size_offset(entry, &size, &offset))
continue;
- }
ent = kmalloc(sizeof(*ent), GFP_KERNEL);
if (!ent)
const char *sym, int offset, char *modname, struct kprobe *pp)
{
char *kprobe_type;
+ void *addr = p->addr;
if (p->pre_handler == pre_handler_kretprobe)
kprobe_type = "r";
- else if (p->pre_handler == setjmp_pre_handler)
- kprobe_type = "j";
else
kprobe_type = "k";
+ if (!kallsyms_show_value())
+ addr = NULL;
+
if (sym)
- seq_printf(pi, "%p %s %s+0x%x %s ",
- p->addr, kprobe_type, sym, offset,
+ seq_printf(pi, "%px %s %s+0x%x %s ",
+ addr, kprobe_type, sym, offset,
(modname ? modname : " "));
- else
- seq_printf(pi, "%p %s %p ",
- p->addr, kprobe_type, p->addr);
+ else /* try to use %pS */
+ seq_printf(pi, "%px %s %pS ",
+ addr, kprobe_type, p->addr);
if (!pp)
pp = p;
struct kprobe_blacklist_entry *ent =
list_entry(v, struct kprobe_blacklist_entry, list);
- seq_printf(m, "0x%px-0x%px\t%ps\n", (void *)ent->start_addr,
- (void *)ent->end_addr, (void *)ent->start_addr);
+ /*
+ * If /proc/kallsyms is not showing kernel address, we won't
+ * show them here either.
+ */
+ if (!kallsyms_show_value())
+ seq_printf(m, "0x%px-0x%px\t%ps\n", NULL, NULL,
+ (void *)ent->start_addr);
+ else
+ seq_printf(m, "0x%px-0x%px\t%ps\n", (void *)ent->start_addr,
+ (void *)ent->end_addr, (void *)ent->start_addr);
return 0;
}
if (!dir)
return -ENOMEM;
- file = debugfs_create_file("list", 0444, dir, NULL,
+ file = debugfs_create_file("list", 0400, dir, NULL,
&debugfs_kprobes_operations);
if (!file)
goto error;
if (!file)
goto error;
- file = debugfs_create_file("blacklist", 0444, dir, NULL,
+ file = debugfs_create_file("blacklist", 0400, dir, NULL,
&debugfs_kprobe_blacklist_ops);
if (!file)
goto error;
#endif /* CONFIG_DEBUG_FS */
module_init(init_kprobes);
-
-/* defined in arch/.../kernel/kprobes.c */
-EXPORT_SYMBOL_GPL(jprobe_return);
}
-#if 0
-static u32 jph_val;
-
-static u32 j_kprobe_target(u32 value)
-{
- if (preemptible()) {
- handler_errors++;
- pr_err("jprobe-handler is preemptible\n");
- }
- if (value != rand1) {
- handler_errors++;
- pr_err("incorrect value in jprobe handler\n");
- }
-
- jph_val = rand1;
- jprobe_return();
- return 0;
-}
-
-static struct jprobe jp = {
- .entry = j_kprobe_target,
- .kp.symbol_name = "kprobe_target"
-};
-
-static int test_jprobe(void)
-{
- int ret;
-
- ret = register_jprobe(&jp);
- if (ret < 0) {
- pr_err("register_jprobe returned %d\n", ret);
- return ret;
- }
-
- ret = target(rand1);
- unregister_jprobe(&jp);
- if (jph_val == 0) {
- pr_err("jprobe handler not called\n");
- handler_errors++;
- }
-
- return 0;
-}
-
-static struct jprobe jp2 = {
- .entry = j_kprobe_target,
- .kp.symbol_name = "kprobe_target2"
-};
-
-static int test_jprobes(void)
-{
- int ret;
- struct jprobe *jps[2] = {&jp, &jp2};
-
- /* addr and flags should be cleard for reusing kprobe. */
- jp.kp.addr = NULL;
- jp.kp.flags = 0;
- ret = register_jprobes(jps, 2);
- if (ret < 0) {
- pr_err("register_jprobes returned %d\n", ret);
- return ret;
- }
-
- jph_val = 0;
- ret = target(rand1);
- if (jph_val == 0) {
- pr_err("jprobe handler not called\n");
- handler_errors++;
- }
-
- jph_val = 0;
- ret = target2(rand1);
- if (jph_val == 0) {
- pr_err("jprobe handler2 not called\n");
- handler_errors++;
- }
- unregister_jprobes(jps, 2);
-
- return 0;
-}
-#else
-#define test_jprobe() (0)
-#define test_jprobes() (0)
-#endif
#ifdef CONFIG_KRETPROBES
static u32 krph_val;
if (ret < 0)
errors++;
- num_tests++;
- ret = test_jprobe();
- if (ret < 0)
- errors++;
-
- num_tests++;
- ret = test_jprobes();
- if (ret < 0)
- errors++;
-
#ifdef CONFIG_KRETPROBES
num_tests++;
ret = test_kretprobe();
/*
* We need to check and see if we modified the pc of the
- * pt_regs, and if so clear the kprobe and return 1 so that we
- * don't do the single stepping.
- * The ftrace kprobe handler leaves it up to us to re-enable
- * preemption here before returning if we've modified the ip.
+ * pt_regs, and if so return 1 so that we don't do the
+ * single stepping.
*/
- if (orig_ip != instruction_pointer(regs)) {
- reset_current_kprobe();
- preempt_enable_no_resched();
+ if (orig_ip != instruction_pointer(regs))
return 1;
- }
if (!ret)
return 0;
}
default n
help
This option provides for testing basic kprobes functionality on
- boot. A sample kprobe, jprobe and kretprobe are inserted and
+ boot. Samples of kprobe and kretprobe are inserted and
verified for functionality.
Say N if you are unsure.
perf record -e '{cycles,instructions}:S' ...
perf report --group
-Normally all events in a event group sample, but with :S only
+Normally all events in an event group sample, but with :S only
the first event (the leader) samples, and it only reads the values of the
other events in the group.
"perf report" to view group events together.
--filter=<filter>::
- Event filter. This option should follow a event selector (-e) which
+ Event filter. This option should follow an event selector (-e) which
selects either tracepoint event(s) or a hardware trace PMU
(e.g. Intel PT or CoreSight).
--exclude-perf::
Don't record events issued by perf itself. This option should follow
- a event selector (-e) which selects tracepoint event(s). It adds a
+ an event selector (-e) which selects tracepoint event(s). It adds a
filter expression 'common_pid != $PERFPID' to filters. If other
'--filter' exists, the new filter expression will be combined with
them by '&&'.
projects / linux-2.6-microblaze.git / commitdiff