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Diffstat (limited to 'kernel/debug/debug_core.c')
-rw-r--r--kernel/debug/debug_core.c81
1 files changed, 60 insertions, 21 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 2b7c9b67931d..9e5934780f41 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -67,9 +67,7 @@ static int kgdb_break_asap;
struct debuggerinfo_struct kgdb_info[NR_CPUS];
-/**
- * kgdb_connected - Is a host GDB connected to us?
- */
+/* kgdb_connected - Is a host GDB connected to us? */
int kgdb_connected;
EXPORT_SYMBOL_GPL(kgdb_connected);
@@ -171,18 +169,18 @@ int __weak kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
{
int err;
- err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
+ err = copy_from_kernel_nofault(bpt->saved_instr, (char *)bpt->bpt_addr,
BREAK_INSTR_SIZE);
if (err)
return err;
- err = probe_kernel_write((char *)bpt->bpt_addr,
+ err = copy_to_kernel_nofault((char *)bpt->bpt_addr,
arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE);
return err;
}
int __weak kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
{
- return probe_kernel_write((char *)bpt->bpt_addr,
+ return copy_to_kernel_nofault((char *)bpt->bpt_addr,
(char *)bpt->saved_instr, BREAK_INSTR_SIZE);
}
@@ -417,6 +415,18 @@ int kgdb_isremovedbreak(unsigned long addr)
return 0;
}
+int kgdb_has_hit_break(unsigned long addr)
+{
+ int i;
+
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if (kgdb_break[i].state == BP_ACTIVE &&
+ kgdb_break[i].bpt_addr == addr)
+ return 1;
+ }
+ return 0;
+}
+
int dbg_remove_all_break(void)
{
int error;
@@ -532,6 +542,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
if (exception_level > 1) {
dump_stack();
+ kgdb_io_module_registered = false;
panic("Recursive entry to debugger");
}
@@ -576,6 +587,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
arch_kgdb_ops.disable_hw_break(regs);
acquirelock:
+ rcu_read_lock();
/*
* Interrupts will be restored by the 'trap return' code, except when
* single stepping.
@@ -635,6 +647,7 @@ return_normal:
atomic_dec(&slaves_in_kgdb);
dbg_touch_watchdogs();
local_irq_restore(flags);
+ rcu_read_unlock();
return 0;
}
cpu_relax();
@@ -653,6 +666,7 @@ return_normal:
raw_spin_unlock(&dbg_master_lock);
dbg_touch_watchdogs();
local_irq_restore(flags);
+ rcu_read_unlock();
goto acquirelock;
}
@@ -668,6 +682,8 @@ return_normal:
if (kgdb_skipexception(ks->ex_vector, ks->linux_regs))
goto kgdb_restore;
+ atomic_inc(&ignore_console_lock_warning);
+
/* Call the I/O driver's pre_exception routine */
if (dbg_io_ops->pre_exception)
dbg_io_ops->pre_exception();
@@ -740,6 +756,8 @@ cpu_master_loop:
if (dbg_io_ops->post_exception)
dbg_io_ops->post_exception();
+ atomic_dec(&ignore_console_lock_warning);
+
if (!kgdb_single_step) {
raw_spin_unlock(&dbg_slave_lock);
/* Wait till all the CPUs have quit from the debugger. */
@@ -772,6 +790,7 @@ kgdb_restore:
raw_spin_unlock(&dbg_master_lock);
dbg_touch_watchdogs();
local_irq_restore(flags);
+ rcu_read_unlock();
return kgdb_info[cpu].ret_state;
}
@@ -920,7 +939,7 @@ static void sysrq_handle_dbg(int key)
kgdb_breakpoint();
}
-static struct sysrq_key_op sysrq_dbg_op = {
+static const struct sysrq_key_op sysrq_dbg_op = {
.handler = sysrq_handle_dbg,
.help_msg = "debug(g)",
.action_msg = "DEBUG",
@@ -946,6 +965,14 @@ void kgdb_panic(const char *msg)
kgdb_breakpoint();
}
+static void kgdb_initial_breakpoint(void)
+{
+ kgdb_break_asap = 0;
+
+ pr_crit("Waiting for connection from remote gdb...\n");
+ kgdb_breakpoint();
+}
+
void __weak kgdb_arch_late(void)
{
}
@@ -956,6 +983,9 @@ void __init dbg_late_init(void)
if (kgdb_io_module_registered)
kgdb_arch_late();
kdb_init(KDB_INIT_FULL);
+
+ if (kgdb_io_module_registered && kgdb_break_asap)
+ kgdb_initial_breakpoint();
}
static int
@@ -1051,14 +1081,6 @@ void kgdb_schedule_breakpoint(void)
}
EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint);
-static void kgdb_initial_breakpoint(void)
-{
- kgdb_break_asap = 0;
-
- pr_crit("Waiting for connection from remote gdb...\n");
- kgdb_breakpoint();
-}
-
/**
* kgdb_register_io_module - register KGDB IO module
* @new_dbg_io_ops: the io ops vector
@@ -1067,15 +1089,22 @@ static void kgdb_initial_breakpoint(void)
*/
int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
{
+ struct kgdb_io *old_dbg_io_ops;
int err;
spin_lock(&kgdb_registration_lock);
- if (dbg_io_ops) {
- spin_unlock(&kgdb_registration_lock);
+ old_dbg_io_ops = dbg_io_ops;
+ if (old_dbg_io_ops) {
+ if (!old_dbg_io_ops->deinit) {
+ spin_unlock(&kgdb_registration_lock);
- pr_err("Another I/O driver is already registered with KGDB\n");
- return -EBUSY;
+ pr_err("KGDB I/O driver %s can't replace %s.\n",
+ new_dbg_io_ops->name, old_dbg_io_ops->name);
+ return -EBUSY;
+ }
+ pr_info("Replacing I/O driver %s with %s\n",
+ old_dbg_io_ops->name, new_dbg_io_ops->name);
}
if (new_dbg_io_ops->init) {
@@ -1090,12 +1119,18 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
spin_unlock(&kgdb_registration_lock);
+ if (old_dbg_io_ops) {
+ old_dbg_io_ops->deinit();
+ return 0;
+ }
+
pr_info("Registered I/O driver %s\n", new_dbg_io_ops->name);
/* Arm KGDB now. */
kgdb_register_callbacks();
- if (kgdb_break_asap)
+ if (kgdb_break_asap &&
+ (!dbg_is_early || IS_ENABLED(CONFIG_ARCH_HAS_EARLY_DEBUG)))
kgdb_initial_breakpoint();
return 0;
@@ -1125,6 +1160,9 @@ void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops)
spin_unlock(&kgdb_registration_lock);
+ if (old_dbg_io_ops->deinit)
+ old_dbg_io_ops->deinit();
+
pr_info("Unregistered I/O driver %s, debugger disabled\n",
old_dbg_io_ops->name);
}
@@ -1165,7 +1203,8 @@ static int __init opt_kgdb_wait(char *str)
kgdb_break_asap = 1;
kdb_init(KDB_INIT_EARLY);
- if (kgdb_io_module_registered)
+ if (kgdb_io_module_registered &&
+ IS_ENABLED(CONFIG_ARCH_HAS_EARLY_DEBUG))
kgdb_initial_breakpoint();
return 0;
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-25 15:40:22 +0000