From 23fa18eaa71266feff7ba8d83022d9e1cc83c65a Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:42:03 +0000
Subject: [PATCH] disable pwm7
---
kernel/arch/arm64/kernel/debug-monitors.c | 163 ++++++++++++++++++++++++++++--------------------------
1 files changed, 85 insertions(+), 78 deletions(-)
diff --git a/kernel/arch/arm64/kernel/debug-monitors.c b/kernel/arch/arm64/kernel/debug-monitors.c
index 501e835..f40c51d 100644
--- a/kernel/arch/arm64/kernel/debug-monitors.c
+++ b/kernel/arch/arm64/kernel/debug-monitors.c
@@ -1,19 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* ARMv8 single-step debug support and mdscr context switching.
*
* Copyright (C) 2012 ARM Limited
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * 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, see <http://www.gnu.org/licenses/>.
*
* Author: Will Deacon <will.deacon@arm.com>
*/
@@ -141,7 +130,7 @@
return 0;
}
-static int debug_monitors_init(void)
+static int __init debug_monitors_init(void)
{
return cpuhp_setup_state(CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
"arm64/debug_monitors:starting",
@@ -167,23 +156,44 @@
#define set_regs_spsr_ss(r) set_user_regs_spsr_ss(&(r)->user_regs)
#define clear_regs_spsr_ss(r) clear_user_regs_spsr_ss(&(r)->user_regs)
-/* 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);
}
/*
@@ -195,17 +205,20 @@
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;
- rcu_read_lock();
+ list = user_mode(regs) ? &user_step_hook : &kernel_step_hook;
- list_for_each_entry_rcu(hook, &step_hook, node) {
+ /*
+ * Since single-step exception disables interrupt, this function is
+ * entirely not preemptible, and we can use rcu list safely here.
+ */
+ list_for_each_entry_rcu(hook, list, node) {
retval = hook->fn(regs, esr);
if (retval == DBG_HOOK_HANDLED)
break;
}
-
- rcu_read_unlock();
return retval;
}
@@ -214,13 +227,6 @@
static void send_user_sigtrap(int si_code)
{
struct pt_regs *regs = current_pt_regs();
- siginfo_t info;
-
- clear_siginfo(&info);
- info.si_signo = SIGTRAP;
- info.si_errno = 0;
- info.si_code = si_code;
- info.si_addr = (void __user *)instruction_pointer(regs);
if (WARN_ON(!user_mode(regs)))
return;
@@ -228,10 +234,11 @@
if (interrupts_enabled(regs))
local_irq_enable();
- arm64_force_sig_info(&info, "User debug trap", current);
+ arm64_force_sig_fault(SIGTRAP, si_code, instruction_pointer(regs),
+ "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;
@@ -243,10 +250,6 @@
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;
@@ -273,61 +276,62 @@
}
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);
+}
+EXPORT_SYMBOL_GPL(register_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;
- rcu_read_lock();
- list_for_each_entry_rcu(hook, &break_hook, node)
- if ((esr & hook->esr_mask) == hook->esr_val)
+ list = user_mode(regs) ? &user_break_hook : &kernel_break_hook;
+
+ /*
+ * Since brk exception disables interrupt, this function is
+ * entirely not preemptible, and we can use rcu list safely here.
+ */
+ 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;
+ if (call_break_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
-#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 (!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;
}
@@ -375,15 +379,13 @@
}
NOKPROBE_SYMBOL(aarch32_break_handler);
-static int __init debug_traps_init(void)
+void __init debug_traps_init(void)
{
hook_debug_fault_code(DBG_ESR_EVT_HWSS, single_step_handler, SIGTRAP,
TRAP_TRACE, "single-step handler");
hook_debug_fault_code(DBG_ESR_EVT_BRK, brk_handler, SIGTRAP,
- TRAP_BRKPT, "ptrace BRK handler");
- return 0;
+ TRAP_BRKPT, "BRK handler");
}
-arch_initcall(debug_traps_init);
/* Re-enable single step for syscall restarting. */
void user_rewind_single_step(struct task_struct *task)
@@ -437,6 +439,11 @@
}
NOKPROBE_SYMBOL(kernel_active_single_step);
+void kernel_rewind_single_step(struct pt_regs *regs)
+{
+ set_regs_spsr_ss(regs);
+}
+
/* ptrace API */
void user_enable_single_step(struct task_struct *task)
{
--
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