Commit 26c8af5f authored by Olaf Hering's avatar Olaf Hering Committed by Paul Mackerras

[POWERPC] print backtrace when entering xmon

xmon does not print a backtrace per default. This is bad on systems with
USB keyboard, the most needed info about the crash is lost.
print a backtrace during the very first xmon entry.

Booting with xmon=nobt disables the autobacktrace functionality.
Signed-off-by: default avatarOlaf Hering <olaf@aepfle.de>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 87fd7724
...@@ -88,6 +88,8 @@ config XMON ...@@ -88,6 +88,8 @@ config XMON
very early during boot. 'xmon=on' will just enable the xmon very early during boot. 'xmon=on' will just enable the xmon
debugger hooks. 'xmon=off' will disable the debugger hooks debugger hooks. 'xmon=off' will disable the debugger hooks
if CONFIG_XMON_DEFAULT is set. if CONFIG_XMON_DEFAULT is set.
xmon will print a backtrace on the very first invocation.
'xmon=nobt' will disable this autobacktrace.
config XMON_DEFAULT config XMON_DEFAULT
bool "Enable xmon by default" bool "Enable xmon by default"
......
...@@ -441,6 +441,8 @@ void __init smp_setup_cpu_maps(void) ...@@ -441,6 +441,8 @@ void __init smp_setup_cpu_maps(void)
int __initdata do_early_xmon; int __initdata do_early_xmon;
#ifdef CONFIG_XMON #ifdef CONFIG_XMON
extern int xmon_no_auto_backtrace;
static int __init early_xmon(char *p) static int __init early_xmon(char *p)
{ {
/* ensure xmon is enabled */ /* ensure xmon is enabled */
...@@ -449,6 +451,8 @@ static int __init early_xmon(char *p) ...@@ -449,6 +451,8 @@ static int __init early_xmon(char *p)
xmon_init(1); xmon_init(1);
if (strncmp(p, "off", 3) == 0) if (strncmp(p, "off", 3) == 0)
xmon_init(0); xmon_init(0);
if (strncmp(p, "nobt", 4) == 0)
xmon_no_auto_backtrace = 1;
if (strncmp(p, "early", 5) != 0) if (strncmp(p, "early", 5) != 0)
return 0; return 0;
} }
......
...@@ -137,10 +137,14 @@ static void bootcmds(void); ...@@ -137,10 +137,14 @@ static void bootcmds(void);
static void proccall(void); static void proccall(void);
void dump_segments(void); void dump_segments(void);
static void symbol_lookup(void); static void symbol_lookup(void);
static void xmon_show_stack(unsigned long sp, unsigned long lr,
unsigned long pc);
static void xmon_print_symbol(unsigned long address, const char *mid, static void xmon_print_symbol(unsigned long address, const char *mid,
const char *after); const char *after);
static const char *getvecname(unsigned long vec); static const char *getvecname(unsigned long vec);
int xmon_no_auto_backtrace;
extern int print_insn_powerpc(unsigned long, unsigned long, int); extern int print_insn_powerpc(unsigned long, unsigned long, int);
extern void xmon_enter(void); extern void xmon_enter(void);
...@@ -736,6 +740,12 @@ cmds(struct pt_regs *excp) ...@@ -736,6 +740,12 @@ cmds(struct pt_regs *excp)
last_cmd = NULL; last_cmd = NULL;
xmon_regs = excp; xmon_regs = excp;
if (!xmon_no_auto_backtrace) {
xmon_no_auto_backtrace = 1;
xmon_show_stack(excp->gpr[1], excp->link, excp->nip);
}
for(;;) { for(;;) {
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
printf("%x:", smp_processor_id()); printf("%x:", smp_processor_id());
......
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