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-rw-r--r--arch/x86/include/asm/kgdb.h3
-rw-r--r--arch/x86/kernel/kgdb.c22
-rw-r--r--arch/x86/kernel/traps.c6
-rw-r--r--include/linux/kgdb.h1
-rw-r--r--kernel/debug/debug_core.c2
-rw-r--r--lib/Kconfig.kgdb9
6 files changed, 41 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kgdb.h b/arch/x86/include/asm/kgdb.h
index e6c6c808489..006da3687cd 100644
--- a/arch/x86/include/asm/kgdb.h
+++ b/arch/x86/include/asm/kgdb.h
@@ -76,4 +76,7 @@ static inline void arch_kgdb_breakpoint(void)
#define BREAK_INSTR_SIZE 1
#define CACHE_FLUSH_IS_SAFE 1
+extern int kgdb_ll_trap(int cmd, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig);
+
#endif /* _ASM_X86_KGDB_H */
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index acba5716993..95b89d4cb8f 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -538,7 +538,7 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_DONE;
}
- if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs))
+ if (kgdb_handle_exception(args->trapnr, args->signr, cmd, regs))
return NOTIFY_DONE;
/* Must touch watchdog before return to normal operation */
@@ -546,6 +546,26 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_STOP;
}
+#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
+int kgdb_ll_trap(int cmd, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig)
+{
+ struct die_args args = {
+ .regs = regs,
+ .str = str,
+ .err = err,
+ .trapnr = trap,
+ .signr = sig,
+
+ };
+
+ if (!kgdb_io_module_registered)
+ return NOTIFY_DONE;
+
+ return __kgdb_notify(&args, cmd);
+}
+#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
+
static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 02cfb9b8f5b..7eaad4c5110 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -15,6 +15,7 @@
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
+#include <linux/kgdb.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ptrace.h>
@@ -451,6 +452,11 @@ void restart_nmi(void)
/* May run on IST stack. */
dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
+#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
+ if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
+ == NOTIFY_STOP)
+ return;
+#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
#ifdef CONFIG_KPROBES
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 406f6f9286f..19d1b29a269 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -60,6 +60,7 @@ struct uart_port;
void kgdb_breakpoint(void);
extern int kgdb_connected;
+extern int kgdb_io_module_registered;
extern atomic_t kgdb_setting_breakpoint;
extern atomic_t kgdb_cpu_doing_single_step;
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 88a83a22537..375e42f0baf 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -66,7 +66,7 @@ int kgdb_connected;
EXPORT_SYMBOL_GPL(kgdb_connected);
/* All the KGDB handlers are installed */
-static int kgdb_io_module_registered;
+int kgdb_io_module_registered;
/* Guard for recursive entry */
static int exception_level;
diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb
index ee8ae7132f2..c56ccb4ad29 100644
--- a/lib/Kconfig.kgdb
+++ b/lib/Kconfig.kgdb
@@ -57,6 +57,15 @@ config KGDB_TESTS_BOOT_STRING
information about other strings you could use beyond the
default of V1F100.
+config KGDB_LOW_LEVEL_TRAP
+ bool "KGDB: Allow debugging with traps in notifiers"
+ depends on X86
+ default n
+ help
+ This will add an extra call back to kgdb for the breakpoint
+ exception handler on which will will allow kgdb to step
+ through a notify handler.
+
config KGDB_KDB
bool "KGDB_KDB: include kdb frontend for kgdb"
default n