#include <linux/init.h>
#include <linux/ptrace.h>
#include <linux/stat.h>
+#include <linux/uaccess.h>
#include <asm/debug-monitors.h>
#include <asm/local.h>
static void clear_os_lock(void *unused)
{
asm volatile("msr oslar_el1, %0" : : "r" (0));
- isb();
}
static int __cpuinit os_lock_notify(struct notifier_block *self,
static int __cpuinit debug_monitors_init(void)
{
/* Clear the OS lock. */
- smp_call_function(clear_os_lock, NULL, 1);
- clear_os_lock(NULL);
+ on_each_cpu(clear_os_lock, NULL, 1);
+ isb();
+ local_dbg_enable();
/* Register hotplug handler. */
register_cpu_notifier(&os_lock_nb);
regs->pstate = spsr;
}
+/* EL1 Single Step Handler hooks */
+static LIST_HEAD(step_hook);
+DEFINE_RWLOCK(step_hook_lock);
+
+void register_step_hook(struct step_hook *hook)
+{
+ write_lock(&step_hook_lock);
+ list_add(&hook->node, &step_hook);
+ write_unlock(&step_hook_lock);
+}
+
+void unregister_step_hook(struct step_hook *hook)
+{
+ write_lock(&step_hook_lock);
+ list_del(&hook->node);
+ write_unlock(&step_hook_lock);
+}
+
+/*
+ * Call registered single step handers
+ * There is no Syndrome info to check for determining the handler.
+ * So we call all the registered handlers, until the right handler is
+ * found which returns zero.
+ */
+static int call_step_hook(struct pt_regs *regs, unsigned int esr)
+{
+ struct step_hook *hook;
+ int retval = DBG_HOOK_ERROR;
+
+ read_lock(&step_hook_lock);
+
+ list_for_each_entry(hook, &step_hook, node) {
+ retval = hook->fn(regs, esr);
+ if (retval == DBG_HOOK_HANDLED)
+ break;
+ }
+
+ read_unlock(&step_hook_lock);
+
+ return retval;
+}
+
static int single_step_handler(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
*/
user_rewind_single_step(current);
} else {
- /* TODO: route to KGDB */
+ if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
+
pr_warning("Unexpected kernel single-step exception at EL1\n");
/*
* Re-enable stepping since we know that we will be
return 0;
}
-static int __init single_step_init(void)
+/*
+ * Breakpoint handler is re-entrant as another breakpoint can
+ * hit within breakpoint handler, especically in kprobes.
+ * Use reader/writer locks instead of plain spinlock.
+ */
+static LIST_HEAD(break_hook);
+DEFINE_RWLOCK(break_hook_lock);
+
+void register_break_hook(struct break_hook *hook)
+{
+ write_lock(&break_hook_lock);
+ list_add(&hook->node, &break_hook);
+ write_unlock(&break_hook_lock);
+}
+
+void unregister_break_hook(struct break_hook *hook)
+{
+ write_lock(&break_hook_lock);
+ list_del(&hook->node);
+ write_unlock(&break_hook_lock);
+}
+
+static int call_break_hook(struct pt_regs *regs, unsigned int esr)
+{
+ struct break_hook *hook;
+ int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;
+
+ read_lock(&break_hook_lock);
+ list_for_each_entry(hook, &break_hook, node)
+ if ((esr & hook->esr_mask) == hook->esr_val)
+ fn = hook->fn;
+ read_unlock(&break_hook_lock);
+
+ return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
+}
+
+static int brk_handler(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ siginfo_t info;
+
+ if (user_mode(regs)) {
+ info = (siginfo_t) {
+ .si_signo = SIGTRAP,
+ .si_errno = 0,
+ .si_code = TRAP_BRKPT,
+ .si_addr = (void __user *)instruction_pointer(regs),
+ };
+
+ force_sig_info(SIGTRAP, &info, current);
+ } else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
+ pr_warning("Unexpected kernel BRK exception at EL1\n");
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+int aarch32_break_handler(struct pt_regs *regs)
+{
+ siginfo_t info;
+ unsigned int instr;
+ bool bp = false;
+ void __user *pc = (void __user *)instruction_pointer(regs);
+
+ if (!compat_user_mode(regs))
+ return -EFAULT;
+
+ if (compat_thumb_mode(regs)) {
+ /* get 16-bit Thumb instruction */
+ get_user(instr, (u16 __user *)pc);
+ if (instr == AARCH32_BREAK_THUMB2_LO) {
+ /* get second half of 32-bit Thumb-2 instruction */
+ get_user(instr, (u16 __user *)(pc + 2));
+ bp = instr == AARCH32_BREAK_THUMB2_HI;
+ } else {
+ bp = instr == AARCH32_BREAK_THUMB;
+ }
+ } else {
+ /* 32-bit ARM instruction */
+ get_user(instr, (u32 __user *)pc);
+ bp = (instr & ~0xf0000000) == AARCH32_BREAK_ARM;
+ }
+
+ if (!bp)
+ return -EFAULT;
+
+ info = (siginfo_t) {
+ .si_signo = SIGTRAP,
+ .si_errno = 0,
+ .si_code = TRAP_BRKPT,
+ .si_addr = pc,
+ };
+
+ force_sig_info(SIGTRAP, &info, current);
+ return 0;
+}
+
+static int __init debug_traps_init(void)
{
hook_debug_fault_code(DBG_ESR_EVT_HWSS, single_step_handler, SIGTRAP,
TRAP_HWBKPT, "single-step handler");
+ hook_debug_fault_code(DBG_ESR_EVT_BRK, brk_handler, SIGTRAP,
+ TRAP_BRKPT, "ptrace BRK handler");
return 0;
}
-arch_initcall(single_step_init);
+arch_initcall(debug_traps_init);
/* Re-enable single step for syscall restarting. */
void user_rewind_single_step(struct task_struct *task)
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff