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Diffstat (limited to 'kernel/kgdb.c')
-rw-r--r--kernel/kgdb.c107
1 files changed, 77 insertions, 30 deletions
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 3ec23c3ec97f..e4dcfb2272a4 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -56,12 +56,14 @@
static int kgdb_break_asap;
+#define KGDB_MAX_THREAD_QUERY 17
struct kgdb_state {
int ex_vector;
int signo;
int err_code;
int cpu;
int pass_exception;
+ unsigned long thr_query;
unsigned long threadid;
long kgdb_usethreadid;
struct pt_regs *linux_regs;
@@ -166,13 +168,6 @@ early_param("nokgdbroundup", opt_nokgdbroundup);
* Weak aliases for breakpoint management,
* can be overriden by architectures when needed:
*/
-int __weak kgdb_validate_break_address(unsigned long addr)
-{
- char tmp_variable[BREAK_INSTR_SIZE];
-
- return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE);
-}
-
int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr)
{
int err;
@@ -191,6 +186,25 @@ int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle)
(char *)bundle, BREAK_INSTR_SIZE);
}
+int __weak kgdb_validate_break_address(unsigned long addr)
+{
+ char tmp_variable[BREAK_INSTR_SIZE];
+ int err;
+ /* Validate setting the breakpoint and then removing it. In the
+ * remove fails, the kernel needs to emit a bad message because we
+ * are deep trouble not being able to put things back the way we
+ * found them.
+ */
+ err = kgdb_arch_set_breakpoint(addr, tmp_variable);
+ if (err)
+ return err;
+ err = kgdb_arch_remove_breakpoint(addr, tmp_variable);
+ if (err)
+ printk(KERN_ERR "KGDB: Critical breakpoint error, kernel "
+ "memory destroyed at: %lx", addr);
+ return err;
+}
+
unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs)
{
return instruction_pointer(regs);
@@ -433,9 +447,14 @@ int kgdb_hex2long(char **ptr, unsigned long *long_val)
{
int hex_val;
int num = 0;
+ int negate = 0;
*long_val = 0;
+ if (**ptr == '-') {
+ negate = 1;
+ (*ptr)++;
+ }
while (**ptr) {
hex_val = hex(**ptr);
if (hex_val < 0)
@@ -446,6 +465,9 @@ int kgdb_hex2long(char **ptr, unsigned long *long_val)
(*ptr)++;
}
+ if (negate)
+ *long_val = -*long_val;
+
return num;
}
@@ -466,7 +488,7 @@ static int write_mem_msg(int binary)
if (err)
return err;
if (CACHE_FLUSH_IS_SAFE)
- flush_icache_range(addr, addr + length + 1);
+ flush_icache_range(addr, addr + length);
return 0;
}
@@ -515,10 +537,16 @@ static void int_to_threadref(unsigned char *id, int value)
static struct task_struct *getthread(struct pt_regs *regs, int tid)
{
/*
- * Non-positive TIDs are remapped idle tasks:
+ * Non-positive TIDs are remapped to the cpu shadow information
*/
- if (tid <= 0)
- return idle_task(-tid);
+ if (tid == 0 || tid == -1)
+ tid = -atomic_read(&kgdb_active) - 2;
+ if (tid < 0) {
+ if (kgdb_info[-tid - 2].task)
+ return kgdb_info[-tid - 2].task;
+ else
+ return idle_task(-tid - 2);
+ }
/*
* find_task_by_pid_ns() does not take the tasklist lock anymore
@@ -562,6 +590,7 @@ static void kgdb_wait(struct pt_regs *regs)
/* Signal the primary CPU that we are done: */
atomic_set(&cpu_in_kgdb[cpu], 0);
+ touch_softlockup_watchdog();
clocksource_touch_watchdog();
local_irq_restore(flags);
}
@@ -725,14 +754,15 @@ setundefined:
}
/*
- * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs:
+ * Remap normal tasks to their real PID,
+ * CPU shadow threads are mapped to -CPU - 2
*/
static inline int shadow_pid(int realpid)
{
if (realpid)
return realpid;
- return -1-raw_smp_processor_id();
+ return -raw_smp_processor_id() - 2;
}
static char gdbmsgbuf[BUFMAX + 1];
@@ -826,7 +856,7 @@ static void gdb_cmd_getregs(struct kgdb_state *ks)
local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
} else {
local_debuggerinfo = NULL;
- for (i = 0; i < NR_CPUS; i++) {
+ for_each_online_cpu(i) {
/*
* Try to find the task on some other
* or possibly this node if we do not
@@ -960,10 +990,13 @@ static int gdb_cmd_reboot(struct kgdb_state *ks)
/* Handle the 'q' query packets */
static void gdb_cmd_query(struct kgdb_state *ks)
{
- struct task_struct *thread;
+ struct task_struct *g;
+ struct task_struct *p;
unsigned char thref[8];
char *ptr;
int i;
+ int cpu;
+ int finished = 0;
switch (remcom_in_buffer[1]) {
case 's':
@@ -973,22 +1006,34 @@ static void gdb_cmd_query(struct kgdb_state *ks)
break;
}
- if (remcom_in_buffer[1] == 'f')
- ks->threadid = 1;
-
+ i = 0;
remcom_out_buffer[0] = 'm';
ptr = remcom_out_buffer + 1;
-
- for (i = 0; i < 17; ks->threadid++) {
- thread = getthread(ks->linux_regs, ks->threadid);
- if (thread) {
- int_to_threadref(thref, ks->threadid);
+ if (remcom_in_buffer[1] == 'f') {
+ /* Each cpu is a shadow thread */
+ for_each_online_cpu(cpu) {
+ ks->thr_query = 0;
+ int_to_threadref(thref, -cpu - 2);
pack_threadid(ptr, thref);
ptr += BUF_THREAD_ID_SIZE;
*(ptr++) = ',';
i++;
}
}
+
+ do_each_thread(g, p) {
+ if (i >= ks->thr_query && !finished) {
+ int_to_threadref(thref, p->pid);
+ pack_threadid(ptr, thref);
+ ptr += BUF_THREAD_ID_SIZE;
+ *(ptr++) = ',';
+ ks->thr_query++;
+ if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
+ finished = 1;
+ }
+ i++;
+ } while_each_thread(g, p);
+
*(--ptr) = '\0';
break;
@@ -1011,15 +1056,15 @@ static void gdb_cmd_query(struct kgdb_state *ks)
error_packet(remcom_out_buffer, -EINVAL);
break;
}
- if (ks->threadid > 0) {
+ if ((int)ks->threadid > 0) {
kgdb_mem2hex(getthread(ks->linux_regs,
ks->threadid)->comm,
remcom_out_buffer, 16);
} else {
static char tmpstr[23 + BUF_THREAD_ID_SIZE];
- sprintf(tmpstr, "Shadow task %d for pid 0",
- (int)(-ks->threadid-1));
+ sprintf(tmpstr, "shadowCPU%d",
+ (int)(-ks->threadid - 2));
kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
}
break;
@@ -1388,6 +1433,7 @@ acquirelock:
atomic_read(&kgdb_cpu_doing_single_step) != cpu) {
atomic_set(&kgdb_active, -1);
+ touch_softlockup_watchdog();
clocksource_touch_watchdog();
local_irq_restore(flags);
@@ -1418,7 +1464,7 @@ acquirelock:
* Get the passive CPU lock which will hold all the non-primary
* CPU in a spin state while the debugger is active
*/
- if (!kgdb_single_step || !kgdb_contthread) {
+ if (!kgdb_single_step) {
for (i = 0; i < NR_CPUS; i++)
atomic_set(&passive_cpu_wait[i], 1);
}
@@ -1431,7 +1477,7 @@ acquirelock:
#ifdef CONFIG_SMP
/* Signal the other CPUs to enter kgdb_wait() */
- if ((!kgdb_single_step || !kgdb_contthread) && kgdb_do_roundup)
+ if ((!kgdb_single_step) && kgdb_do_roundup)
kgdb_roundup_cpus(flags);
#endif
@@ -1450,7 +1496,7 @@ acquirelock:
kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
kgdb_deactivate_sw_breakpoints();
kgdb_single_step = 0;
- kgdb_contthread = NULL;
+ kgdb_contthread = current;
exception_level = 0;
/* Talk to debugger with gdbserial protocol */
@@ -1464,7 +1510,7 @@ acquirelock:
kgdb_info[ks->cpu].task = NULL;
atomic_set(&cpu_in_kgdb[ks->cpu], 0);
- if (!kgdb_single_step || !kgdb_contthread) {
+ if (!kgdb_single_step) {
for (i = NR_CPUS-1; i >= 0; i--)
atomic_set(&passive_cpu_wait[i], 0);
/*
@@ -1480,6 +1526,7 @@ acquirelock:
kgdb_restore:
/* Free kgdb_active */
atomic_set(&kgdb_active, -1);
+ touch_softlockup_watchdog();
clocksource_touch_watchdog();
local_irq_restore(flags);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 19:30:26 +0000