ARM: rockchip_defconfig: update by savedefconfig

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / debug-monitors.c

diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 8aee3aeec3e687edde6f5be67233299e7a4f7d4f..6de6d9f43b959fd1cbb45a16bdc33bba524fccd6 100644 (file)
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -23,6 +23,7 @@
 #include <linux/hardirq.h>
 #include <linux/init.h>
 #include <linux/ptrace.h>
+#include <linux/kprobes.h>
 #include <linux/stat.h>
 #include <linux/uaccess.h>
 
@@ -48,6 +49,7 @@ static void mdscr_write(u32 mdscr)
        asm volatile("msr mdscr_el1, %0" :: "r" (mdscr));
        local_dbg_restore(flags);
 }
+NOKPROBE_SYMBOL(mdscr_write);
 
 static u32 mdscr_read(void)
 {
@@ -55,6 +57,7 @@ static u32 mdscr_read(void)
        asm volatile("mrs %0, mdscr_el1" : "=r" (mdscr));
        return mdscr;
 }
+NOKPROBE_SYMBOL(mdscr_read);
 
 /*
  * Allow root to disable self-hosted debug from userspace.
@@ -103,6 +106,7 @@ void enable_debug_monitors(enum dbg_active_el el)
                mdscr_write(mdscr);
        }
 }
+NOKPROBE_SYMBOL(enable_debug_monitors);
 
 void disable_debug_monitors(enum dbg_active_el el)
 {
@@ -123,6 +127,7 @@ void disable_debug_monitors(enum dbg_active_el el)
                mdscr_write(mdscr);
        }
 }
+NOKPROBE_SYMBOL(disable_debug_monitors);
 
 /*
  * OS lock clearing.
@@ -152,7 +157,6 @@ static int debug_monitors_init(void)
        /* Clear the OS lock. */
        on_each_cpu(clear_os_lock, NULL, 1);
        isb();
-       local_dbg_enable();
 
        /* Register hotplug handler. */
        __register_cpu_notifier(&os_lock_nb);
@@ -174,6 +178,7 @@ static void set_regs_spsr_ss(struct pt_regs *regs)
        spsr |= DBG_SPSR_SS;
        regs->pstate = spsr;
 }
+NOKPROBE_SYMBOL(set_regs_spsr_ss);
 
 static void clear_regs_spsr_ss(struct pt_regs *regs)
 {
@@ -183,23 +188,25 @@ static void clear_regs_spsr_ss(struct pt_regs *regs)
        spsr &= ~DBG_SPSR_SS;
        regs->pstate = spsr;
 }
+NOKPROBE_SYMBOL(clear_regs_spsr_ss);
 
 /* EL1 Single Step Handler hooks */
 static LIST_HEAD(step_hook);
-static DEFINE_RWLOCK(step_hook_lock);
+static DEFINE_SPINLOCK(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);
+       spin_lock(&step_hook_lock);
+       list_add_rcu(&hook->node, &step_hook);
+       spin_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);
+       spin_lock(&step_hook_lock);
+       list_del_rcu(&hook->node);
+       spin_unlock(&step_hook_lock);
+       synchronize_rcu();
 }
 
 /*
@@ -213,18 +220,19 @@ 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);
+       rcu_read_lock();
 
-       list_for_each_entry(hook, &step_hook, node)     {
+       list_for_each_entry_rcu(hook, &step_hook, node) {
                retval = hook->fn(regs, esr);
                if (retval == DBG_HOOK_HANDLED)
                        break;
        }
 
-       read_unlock(&step_hook_lock);
+       rcu_read_unlock();
 
        return retval;
 }
+NOKPROBE_SYMBOL(call_step_hook);
 
 static int single_step_handler(unsigned long addr, unsigned int esr,
                               struct pt_regs *regs)
@@ -253,6 +261,10 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
                 */
                user_rewind_single_step(current);
        } else {
+#ifdef CONFIG_KPROBES
+               if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED)
+                       return 0;
+#endif
                if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
                        return 0;
 
@@ -266,6 +278,7 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
 
        return 0;
 }
+NOKPROBE_SYMBOL(single_step_handler);
 
 /*
  * Breakpoint handler is re-entrant as another breakpoint can
@@ -303,6 +316,7 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
 
        return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
 }
+NOKPROBE_SYMBOL(call_break_hook);
 
 static int brk_handler(unsigned long addr, unsigned int esr,
                       struct pt_regs *regs)
@@ -318,13 +332,21 @@ static int brk_handler(unsigned long addr, unsigned int esr,
                };
 
                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");
+       }
+#ifdef CONFIG_KPROBES
+       else if ((esr & BRK64_ESR_MASK) == BRK64_ESR_KPROBES) {
+               if (kprobe_breakpoint_handler(regs, esr) != DBG_HOOK_HANDLED)
+                       return -EFAULT;
+       }
+#endif
+       else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
+               pr_warn("Unexpected kernel BRK exception at EL1\n");
                return -EFAULT;
        }
 
        return 0;
 }
+NOKPROBE_SYMBOL(brk_handler);
 
 int aarch32_break_handler(struct pt_regs *regs)
 {
@@ -369,6 +391,7 @@ int aarch32_break_handler(struct pt_regs *regs)
        force_sig_info(SIGTRAP, &info, current);
        return 0;
 }
+NOKPROBE_SYMBOL(aarch32_break_handler);
 
 static int __init debug_traps_init(void)
 {
@@ -390,6 +413,7 @@ void user_rewind_single_step(struct task_struct *task)
        if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP))
                set_regs_spsr_ss(task_pt_regs(task));
 }
+NOKPROBE_SYMBOL(user_rewind_single_step);
 
 void user_fastforward_single_step(struct task_struct *task)
 {
@@ -405,6 +429,7 @@ void kernel_enable_single_step(struct pt_regs *regs)
        mdscr_write(mdscr_read() | DBG_MDSCR_SS);
        enable_debug_monitors(DBG_ACTIVE_EL1);
 }
+NOKPROBE_SYMBOL(kernel_enable_single_step);
 
 void kernel_disable_single_step(void)
 {
@@ -412,21 +437,27 @@ void kernel_disable_single_step(void)
        mdscr_write(mdscr_read() & ~DBG_MDSCR_SS);
        disable_debug_monitors(DBG_ACTIVE_EL1);
 }
+NOKPROBE_SYMBOL(kernel_disable_single_step);
 
 int kernel_active_single_step(void)
 {
        WARN_ON(!irqs_disabled());
        return mdscr_read() & DBG_MDSCR_SS;
 }
+NOKPROBE_SYMBOL(kernel_active_single_step);
 
 /* ptrace API */
 void user_enable_single_step(struct task_struct *task)
 {
-       set_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
-       set_regs_spsr_ss(task_pt_regs(task));
+       struct thread_info *ti = task_thread_info(task);
+
+       if (!test_and_set_ti_thread_flag(ti, TIF_SINGLESTEP))
+               set_regs_spsr_ss(task_pt_regs(task));
 }
+NOKPROBE_SYMBOL(user_enable_single_step);
 
 void user_disable_single_step(struct task_struct *task)
 {
        clear_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
 }
+NOKPROBE_SYMBOL(user_disable_single_step);