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-rw-r--r--kernel/debug/debug_core.c69
1 files changed, 45 insertions, 24 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1adf62b39b9..0874e2edd27 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -27,6 +27,9 @@
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
+
+#define pr_fmt(fmt) "KGDB: " fmt
+
#include <linux/pid_namespace.h>
#include <linux/clocksource.h>
#include <linux/serial_core.h>
@@ -196,8 +199,8 @@ int __weak kgdb_validate_break_address(unsigned long addr)
return err;
err = kgdb_arch_remove_breakpoint(&tmp);
if (err)
- printk(KERN_ERR "KGDB: Critical breakpoint error, kernel "
- "memory destroyed at: %lx", addr);
+ pr_err("Critical breakpoint error, kernel memory destroyed at: %lx\n",
+ addr);
return err;
}
@@ -256,8 +259,8 @@ int dbg_activate_sw_breakpoints(void)
error = kgdb_arch_set_breakpoint(&kgdb_break[i]);
if (error) {
ret = error;
- printk(KERN_INFO "KGDB: BP install failed: %lx",
- kgdb_break[i].bpt_addr);
+ pr_info("BP install failed: %lx\n",
+ kgdb_break[i].bpt_addr);
continue;
}
@@ -319,8 +322,8 @@ int dbg_deactivate_sw_breakpoints(void)
continue;
error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
if (error) {
- printk(KERN_INFO "KGDB: BP remove failed: %lx\n",
- kgdb_break[i].bpt_addr);
+ pr_info("BP remove failed: %lx\n",
+ kgdb_break[i].bpt_addr);
ret = error;
}
@@ -367,7 +370,7 @@ int dbg_remove_all_break(void)
goto setundefined;
error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
if (error)
- printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n",
+ pr_err("breakpoint remove failed: %lx\n",
kgdb_break[i].bpt_addr);
setundefined:
kgdb_break[i].state = BP_UNDEFINED;
@@ -400,9 +403,9 @@ static int kgdb_io_ready(int print_wait)
if (print_wait) {
#ifdef CONFIG_KGDB_KDB
if (!dbg_kdb_mode)
- printk(KERN_CRIT "KGDB: waiting... or $3#33 for KDB\n");
+ pr_crit("waiting... or $3#33 for KDB\n");
#else
- printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
+ pr_crit("Waiting for remote debugger\n");
#endif
}
return 1;
@@ -430,8 +433,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
exception_level = 0;
kgdb_skipexception(ks->ex_vector, ks->linux_regs);
dbg_activate_sw_breakpoints();
- printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
- addr);
+ pr_crit("re-enter error: breakpoint removed %lx\n", addr);
WARN_ON_ONCE(1);
return 1;
@@ -444,7 +446,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
panic("Recursive entry to debugger");
}
- printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
+ pr_crit("re-enter exception: ALL breakpoints killed\n");
#ifdef CONFIG_KGDB_KDB
/* Allow kdb to debug itself one level */
return 0;
@@ -471,6 +473,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
int cpu;
int trace_on = 0;
int online_cpus = num_online_cpus();
+ u64 time_left;
kgdb_info[ks->cpu].enter_kgdb++;
kgdb_info[ks->cpu].exception_state |= exception_state;
@@ -595,9 +598,13 @@ return_normal:
/*
* Wait for the other CPUs to be notified and be waiting for us:
*/
- while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) +
- atomic_read(&slaves_in_kgdb)) != online_cpus)
+ time_left = loops_per_jiffy * HZ;
+ while (kgdb_do_roundup && --time_left &&
+ (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) !=
+ online_cpus)
cpu_relax();
+ if (!time_left)
+ pr_crit("Timed out waiting for secondary CPUs.\n");
/*
* At this point the primary processor is completely
@@ -689,6 +696,14 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
if (arch_kgdb_ops.enable_nmi)
arch_kgdb_ops.enable_nmi(0);
+ /*
+ * Avoid entering the debugger if we were triggered due to an oops
+ * but panic_timeout indicates the system should automatically
+ * reboot on panic. We don't want to get stuck waiting for input
+ * on such systems, especially if its "just" an oops.
+ */
+ if (signo != SIGTRAP && panic_timeout)
+ return 1;
memset(ks, 0, sizeof(struct kgdb_state));
ks->cpu = raw_smp_processor_id();
@@ -795,15 +810,15 @@ static struct console kgdbcons = {
static void sysrq_handle_dbg(int key)
{
if (!dbg_io_ops) {
- printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
+ pr_crit("ERROR: No KGDB I/O module available\n");
return;
}
if (!kgdb_connected) {
#ifdef CONFIG_KGDB_KDB
if (!dbg_kdb_mode)
- printk(KERN_CRIT "KGDB or $3#33 for KDB\n");
+ pr_crit("KGDB or $3#33 for KDB\n");
#else
- printk(KERN_CRIT "Entering KGDB\n");
+ pr_crit("Entering KGDB\n");
#endif
}
@@ -821,6 +836,15 @@ static int kgdb_panic_event(struct notifier_block *self,
unsigned long val,
void *data)
{
+ /*
+ * Avoid entering the debugger if we were triggered due to a panic
+ * We don't want to get stuck waiting for input from user in such case.
+ * panic_timeout indicates the system should automatically
+ * reboot on panic.
+ */
+ if (panic_timeout)
+ return NOTIFY_DONE;
+
if (dbg_kdb_mode)
kdb_printf("PANIC: %s\n", (char *)data);
kgdb_breakpoint();
@@ -945,7 +969,7 @@ static void kgdb_initial_breakpoint(void)
{
kgdb_break_asap = 0;
- printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
+ pr_crit("Waiting for connection from remote gdb...\n");
kgdb_breakpoint();
}
@@ -964,8 +988,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
if (dbg_io_ops) {
spin_unlock(&kgdb_registration_lock);
- printk(KERN_ERR "kgdb: Another I/O driver is already "
- "registered with KGDB.\n");
+ pr_err("Another I/O driver is already registered with KGDB\n");
return -EBUSY;
}
@@ -981,8 +1004,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
spin_unlock(&kgdb_registration_lock);
- printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
- new_dbg_io_ops->name);
+ pr_info("Registered I/O driver %s\n", new_dbg_io_ops->name);
/* Arm KGDB now. */
kgdb_register_callbacks();
@@ -1017,8 +1039,7 @@ void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops)
spin_unlock(&kgdb_registration_lock);
- printk(KERN_INFO
- "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
+ pr_info("Unregistered I/O driver %s, debugger disabled\n",
old_dbg_io_ops->name);
}
EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-24 22:38:06 +0000