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Diffstat (limited to 'arch/arm64/kernel/debug-monitors.c')
-rw-r--r--arch/arm64/kernel/debug-monitors.c115
1 files changed, 67 insertions, 48 deletions
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index d7bb6aefae0a..555b6bd2f3d6 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -135,6 +135,7 @@ NOKPROBE_SYMBOL(disable_debug_monitors);
*/
static int clear_os_lock(unsigned int cpu)
{
+ write_sysreg(0, osdlr_el1);
write_sysreg(0, oslar_el1);
isb();
return 0;
@@ -163,25 +164,46 @@ static void clear_regs_spsr_ss(struct pt_regs *regs)
}
NOKPROBE_SYMBOL(clear_regs_spsr_ss);
-/* EL1 Single Step Handler hooks */
-static LIST_HEAD(step_hook);
-static DEFINE_SPINLOCK(step_hook_lock);
+static DEFINE_SPINLOCK(debug_hook_lock);
+static LIST_HEAD(user_step_hook);
+static LIST_HEAD(kernel_step_hook);
-void register_step_hook(struct step_hook *hook)
+static void register_debug_hook(struct list_head *node, struct list_head *list)
{
- spin_lock(&step_hook_lock);
- list_add_rcu(&hook->node, &step_hook);
- spin_unlock(&step_hook_lock);
+ spin_lock(&debug_hook_lock);
+ list_add_rcu(node, list);
+ spin_unlock(&debug_hook_lock);
+
}
-void unregister_step_hook(struct step_hook *hook)
+static void unregister_debug_hook(struct list_head *node)
{
- spin_lock(&step_hook_lock);
- list_del_rcu(&hook->node);
- spin_unlock(&step_hook_lock);
+ spin_lock(&debug_hook_lock);
+ list_del_rcu(node);
+ spin_unlock(&debug_hook_lock);
synchronize_rcu();
}
+void register_user_step_hook(struct step_hook *hook)
+{
+ register_debug_hook(&hook->node, &user_step_hook);
+}
+
+void unregister_user_step_hook(struct step_hook *hook)
+{
+ unregister_debug_hook(&hook->node);
+}
+
+void register_kernel_step_hook(struct step_hook *hook)
+{
+ register_debug_hook(&hook->node, &kernel_step_hook);
+}
+
+void unregister_kernel_step_hook(struct step_hook *hook)
+{
+ unregister_debug_hook(&hook->node);
+}
+
/*
* Call registered single step handlers
* There is no Syndrome info to check for determining the handler.
@@ -191,11 +213,14 @@ void unregister_step_hook(struct step_hook *hook)
static int call_step_hook(struct pt_regs *regs, unsigned int esr)
{
struct step_hook *hook;
+ struct list_head *list;
int retval = DBG_HOOK_ERROR;
+ list = user_mode(regs) ? &user_step_hook : &kernel_step_hook;
+
rcu_read_lock();
- list_for_each_entry_rcu(hook, &step_hook, node) {
+ list_for_each_entry_rcu(hook, list, node) {
retval = hook->fn(regs, esr);
if (retval == DBG_HOOK_HANDLED)
break;
@@ -222,7 +247,7 @@ static void send_user_sigtrap(int si_code)
"User debug trap");
}
-static int single_step_handler(unsigned long addr, unsigned int esr,
+static int single_step_handler(unsigned long unused, unsigned int esr,
struct pt_regs *regs)
{
bool handler_found = false;
@@ -234,10 +259,6 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
if (!reinstall_suspended_bps(regs))
return 0;
-#ifdef CONFIG_KPROBES
- if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED)
- handler_found = true;
-#endif
if (!handler_found && call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
handler_found = true;
@@ -264,61 +285,59 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
}
NOKPROBE_SYMBOL(single_step_handler);
-/*
- * 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);
-static DEFINE_SPINLOCK(break_hook_lock);
+static LIST_HEAD(user_break_hook);
+static LIST_HEAD(kernel_break_hook);
-void register_break_hook(struct break_hook *hook)
+void register_user_break_hook(struct break_hook *hook)
{
- spin_lock(&break_hook_lock);
- list_add_rcu(&hook->node, &break_hook);
- spin_unlock(&break_hook_lock);
+ register_debug_hook(&hook->node, &user_break_hook);
}
-void unregister_break_hook(struct break_hook *hook)
+void unregister_user_break_hook(struct break_hook *hook)
{
- spin_lock(&break_hook_lock);
- list_del_rcu(&hook->node);
- spin_unlock(&break_hook_lock);
- synchronize_rcu();
+ unregister_debug_hook(&hook->node);
+}
+
+void register_kernel_break_hook(struct break_hook *hook)
+{
+ register_debug_hook(&hook->node, &kernel_break_hook);
+}
+
+void unregister_kernel_break_hook(struct break_hook *hook)
+{
+ unregister_debug_hook(&hook->node);
}
static int call_break_hook(struct pt_regs *regs, unsigned int esr)
{
struct break_hook *hook;
+ struct list_head *list;
int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;
+ list = user_mode(regs) ? &user_break_hook : &kernel_break_hook;
+
rcu_read_lock();
- list_for_each_entry_rcu(hook, &break_hook, node)
- if ((esr & hook->esr_mask) == hook->esr_val)
+ list_for_each_entry_rcu(hook, list, node) {
+ unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
+
+ if ((comment & ~hook->mask) == hook->imm)
fn = hook->fn;
+ }
rcu_read_unlock();
return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
}
NOKPROBE_SYMBOL(call_break_hook);
-static int brk_handler(unsigned long addr, unsigned int esr,
+static int brk_handler(unsigned long unused, unsigned int esr,
struct pt_regs *regs)
{
- bool handler_found = false;
-
-#ifdef CONFIG_KPROBES
- if ((esr & BRK64_ESR_MASK) == BRK64_ESR_KPROBES) {
- if (kprobe_breakpoint_handler(regs, esr) == DBG_HOOK_HANDLED)
- handler_found = true;
- }
-#endif
- if (!handler_found && call_break_hook(regs, esr) == DBG_HOOK_HANDLED)
- handler_found = true;
+ if (call_break_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
- if (!handler_found && user_mode(regs)) {
+ if (user_mode(regs)) {
send_user_sigtrap(TRAP_BRKPT);
- } else if (!handler_found) {
+ } else {
pr_warn("Unexpected kernel BRK exception at EL1\n");
return -EFAULT;
}