Modified: trunk/include/linux/kgdb.h (8991 => 8992)
--- trunk/include/linux/kgdb.h 2010-07-15 13:25:06 UTC (rev 8991)
+++ trunk/include/linux/kgdb.h 2010-07-16 10:50:39 UTC (rev 8992)
@@ -106,6 +106,7 @@
#endif
#define KGDB_HW_BREAKPOINT 1
+#define KGDB_THR_PROC_SWAP 2
/*
* Functions each KGDB-supporting architecture must provide:
@@ -202,6 +203,19 @@
*/
extern void kgdb_roundup_cpus(unsigned long flags);
+/**
+ * kgdb_roundup_cpu - Get spcific CPU into a holding pattern
+ * @cpu: Specific cpu id
+ * @flags: Current IRQ state
+ *
+ * On SMP systems, we need to switch cpu from current active one to
+ * the other passive one. This get current active CPU into a known state
+ * in kgdb_wait().
+ *
+ * On non-SMP systems, this is not called.
+ */
+extern void kgdb_roundup_cpu(int cpu, unsigned long flags);
+
/* Optional functions. */
extern int kgdb_validate_break_address(unsigned long addr);
extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
Modified: trunk/kernel/kgdb.c (8991 => 8992)
--- trunk/kernel/kgdb.c 2010-07-15 13:25:06 UTC (rev 8991)
+++ trunk/kernel/kgdb.c 2010-07-16 10:50:39 UTC (rev 8992)
@@ -1048,7 +1048,7 @@
}
/* Handle the 'H' task query packets */
-static void gdb_cmd_task(struct kgdb_state *ks)
+static int gdb_cmd_task(struct kgdb_state *ks)
{
struct task_struct *thread;
char *ptr;
@@ -1065,6 +1065,15 @@
kgdb_usethread = thread;
ks->kgdb_usethreadid = ks->threadid;
strcpy(remcom_out_buffer, "OK");
+#ifdef CONFIG_SMP
+ /* switch cpu only when it is not a thread query request */
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ !ks->thr_query && ks->kgdb_usethreadid < -1) {
+ kgdb_roundup_cpu(raw_smp_processor_id(), 0);
+ kgdb_contthread = kgdb_usethread;
+ return 1;
+ }
+#endif
break;
case 'c':
ptr = &remcom_in_buffer[2];
@@ -1082,6 +1091,8 @@
strcpy(remcom_out_buffer, "OK");
break;
}
+
+ return 0;
}
/* Handle the 'T' thread query packets */
@@ -1090,6 +1101,9 @@
char *ptr = &remcom_in_buffer[1];
struct task_struct *thread;
+ /* reset thread query count before thread operation */
+ ks->thr_query = 0;
+
kgdb_hex2long(&ptr, &ks->threadid);
thread = getthread(ks->linux_regs, ks->threadid);
if (thread)
@@ -1202,20 +1216,31 @@
memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
if (kgdb_connected) {
- unsigned char thref[8];
- char *ptr;
+ /* reply the thread switch request after finish swtiching cpu */
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ !kgdb_single_step && kgdb_contthread == current) {
+ remcom_out_buffer[0] = 'O';
+ remcom_out_buffer[1] = 'K';
+ remcom_out_buffer[2] = 0;
+ put_packet(remcom_out_buffer);
+ } else {
+ unsigned char thref[8];
+ char *ptr;
- /* Reply to host that an exception has occurred */
- ptr = remcom_out_buffer;
- *ptr++ = 'T';
- ptr = pack_hex_byte(ptr, ks->signo);
- ptr += strlen(strcpy(ptr, "thread:"));
- int_to_threadref(thref, shadow_pid(current->pid));
- ptr = pack_threadid(ptr, thref);
- *ptr++ = ';';
- put_packet(remcom_out_buffer);
+ /* Reply to host that an exception has occurred */
+ ptr = remcom_out_buffer;
+ *ptr++ = 'T';
+ ptr = pack_hex_byte(ptr, ks->signo);
+ ptr += strlen(strcpy(ptr, "thread:"));
+ int_to_threadref(thref, shadow_pid(current->pid));
+ ptr = pack_threadid(ptr, thref);
+ *ptr++ = ';';
+ put_packet(remcom_out_buffer);
+ }
}
+ kgdb_single_step = 0;
+ kgdb_contthread = current;
kgdb_usethread = kgdb_info[ks->cpu].task;
ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
ks->pass_exception = 0;
@@ -1262,7 +1287,8 @@
gdb_cmd_query(ks);
break;
case 'H': /* task related */
- gdb_cmd_task(ks);
+ if (gdb_cmd_task(ks))
+ return 0;
break;
case 'T': /* Query thread status */
gdb_cmd_thread(ks);
@@ -1302,6 +1328,7 @@
if (error >= 0 || remcom_in_buffer[0] == 'D' ||
remcom_in_buffer[0] == 'k') {
error = 0;
+ kgdb_contthread = NULL;
goto kgdb_exit;
}
@@ -1451,13 +1478,17 @@
* CPU in a spin state while the debugger is active
*/
if (!kgdb_single_step) {
- for (i = 0; i < NR_CPUS; i++)
- atomic_inc(&passive_cpu_wait[i]);
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ kgdb_contthread == current)
+ atomic_inc(&passive_cpu_wait[cpu]);
+ else
+ for (i = 0; i < NR_CPUS; i++)
+ atomic_inc(&passive_cpu_wait[i]);
}
#ifdef CONFIG_SMP
/* Signal the other CPUs to enter kgdb_wait() */
- if ((!kgdb_single_step) && kgdb_do_roundup)
+ if ((!kgdb_single_step) && kgdb_do_roundup && kgdb_contthread != current)
kgdb_roundup_cpus(flags);
#endif
@@ -1475,8 +1506,6 @@
*/
kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
kgdb_deactivate_sw_breakpoints();
- kgdb_single_step = 0;
- kgdb_contthread = current;
exception_level = 0;
trace_on = tracing_is_on();
if (trace_on)
@@ -1492,15 +1521,22 @@
atomic_dec(&cpu_in_kgdb[ks->cpu]);
if (!kgdb_single_step) {
- for (i = NR_CPUS-1; i >= 0; i--)
+ /* wake up next master cpu when do real cpu switch */
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ kgdb_contthread) {
+ i = -(ks->kgdb_usethreadid + 2);
atomic_dec(&passive_cpu_wait[i]);
- /*
- * Wait till all the CPUs have quit
- * from the debugger.
- */
- for_each_online_cpu(i) {
- while (atomic_read(&cpu_in_kgdb[i]))
- cpu_relax();
+ } else {
+ for (i = NR_CPUS-1; i >= 0; i--)
+ atomic_dec(&passive_cpu_wait[i]);
+ /*
+ * Wait till all the CPUs have quit
+ * from the debugger.
+ */
+ for_each_online_cpu(i) {
+ while (atomic_read(&cpu_in_kgdb[i]))
+ cpu_relax();
+ }
}
}
@@ -1569,6 +1605,18 @@
kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
kgdb_cpu_enter(ks, regs);
kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE;
+
+ /* Trap into kgdb as the active CPU if gdb asks to switch. */
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ kgdb_contthread == current) {
+#ifdef __ARCH_SYNC_CORE_ICACHE
+ resync_core_icache();
+#endif
+#ifdef __ARCH_SYNC_CORE_DCACHE
+ resync_core_dcache();
+#endif
+ kgdb_breakpoint();
+ }
return 0;
}
#endif
