[kitten] push by kevin.pe...@gmail.com - BUG_FIX: Fix gdb concurrent breakpoint synchronization bug. on 2013-12-13 21:16 GMT

[kit...@googlecode.com]

Revision: 0a8f32ee74da
Branch: default
Author: Angen Zheng <angen...@gmail.com>
Date: Fri Dec 13 21:15:11 2013 UTC
Log: BUG_FIX: Fix gdb concurrent breakpoint synchronization bug.
http://code.google.com/p/kitten/source/detail?r=0a8f32ee74da

Modified:
/kernel/gdb.c

=======================================
--- /kernel/gdb.c Wed Nov 6 19:48:40 2013 UTC
+++ /kernel/gdb.c Fri Dec 13 21:15:11 2013 UTC
@@ -566,21 +566,33 @@
spin_unlock_irqrestore(&task->aspace->lock, irqstate);
}

-static void gdb_stop_or_resume_task(struct task_struct *task, int
req_type){
- if(task == NULL){
- return;
- }
+static void gdb_stop_or_resume_all(struct task_struct *task, int req_type){
+ if(task == NULL){
+ return;
+ }

- if(task->id == task->aspace->id){//GDB ALL stop mode, stop or resume all
threads within the process
- struct task_struct *tsk;
- struct aspace *aspace = aspace_acquire(task->aspace->id);
- list_for_each_entry(tsk, &aspace->task_list, aspace_link) {
- gdb_stop_or_resume_single_task(tsk, req_type);
- }
- aspace_release(aspace);
- }else{
- gdb_stop_or_resume_single_task(task, req_type);
- }
+ struct task_struct *tsk;
+ struct aspace *aspace = aspace_acquire(task->aspace->id);
+ list_for_each_entry(tsk, &aspace->task_list, aspace_link) {
+ gdb_stop_or_resume_single_task(tsk, req_type);
+ }
+ aspace_release(aspace);
+}
+
+static void gdb_stop_or_resume_all_except(struct task_struct *task, id_t
task_id, int req_type){
+ if(task == NULL){
+ return;
+ }
+
+ struct task_struct *tsk;
+ struct aspace *aspace = aspace_acquire(task->aspace->id);
+ list_for_each_entry(tsk, &aspace->task_list, aspace_link) {
+ if(tsk->id == task_id){
+ continue;
+ }
+ gdb_stop_or_resume_single_task(tsk, req_type);
+ }
+ aspace_release(aspace);
}

/*
@@ -961,7 +973,7 @@
gdb_hex2long(&ptr, &gs->threadid);

if(gs->threadid == -1){//Hg-1
- thread = NULL;
+ thread = TASK_PTR(gs->lwk_regs);
}else if(gs->threadid == 0){
thread = TASK_PTR(gs->lwk_regs);
}else{
@@ -982,12 +994,13 @@
thread = TASK_PTR(gs->lwk_regs);
} else {
if(gs->threadid == -1){//Hc-1 continue command apply to all threads
- gs->threadid = ggs->pid;
- }
- thread = get_task(ggs->pid, gs->threadid);
- if (!thread) {
- error_packet(ggs->remcom_out_buffer, -EINVAL);
- break;
+ thread = TASK_PTR(gs->lwk_regs);
+ }else{
+ thread = get_task(ggs->pid, gs->threadid);
+ if (!thread) {
+ error_packet(ggs->remcom_out_buffer, -EINVAL);
+ break;
+ }
}
}
ggs->gdb_contthread = thread;
@@ -1206,9 +1219,12 @@
gdb_exit:
if (gs->pass_exception)
error = -1;
- gdb_stop_or_resume_task(ggs->gdb_usethread, GDB_RESUME_TASK);
- gdb_stop_or_resume_task(ggs->gdb_contthread, GDB_RESUME_TASK);
-
+ if(ggs->remcom_in_buffer[0] == 's'){
+ gdb_stop_or_resume_single_task(TASK_PTR(gs->lwk_regs), GDB_RESUME_TASK);
+ }else{
+ id_t pid = TASK_PTR(gs->lwk_regs)->aspace->id;
+ gdb_stop_or_resume_all(get_task(pid, pid), GDB_RESUME_TASK);
+ }
return error;
}
/*
@@ -1233,13 +1249,13 @@
//int i;
int cpu;

- gs->cpu = raw_smp_processor_id();
+ gs->cpu = raw_smp_processor_id();
gs->ex_vector = evector;
- gs->signo = signo;
+ gs->signo = signo;
gs->ex_vector = evector;
gs->err_code = ecode;
gs->lwk_regs = regs;
- gs->pass_exception = 0;
+ gs->pass_exception = 0;

struct task_struct *task = TASK_PTR(regs);
struct gdb_per_process_state *ggs = gdb_htable_lookup(task->aspace->id);
@@ -1247,8 +1263,6 @@
printk("GDB Error: no corresponding gdb global state for process(%d)\n",
ggs->pid);
return -1;
}
- ggs->gdb_usethread = task;
- ggs->pid = task->aspace->id;

acquirelock:
/*
@@ -1292,8 +1306,6 @@
if (gdb_skipexception(ggs->gdb_break, ggs->pid, gs->ex_vector,
gs->lwk_regs))
goto gdb_restore;

- gdb_disable_hw_debug(gs->lwk_regs);
-
/* No need to signal other CPUs to enter gdb_wait???
* Get the passive CPU lock which will hold all the non-primary
* CPU in a spin state while the debugger is active
@@ -1329,10 +1341,13 @@
* in the debugger and all secondary CPUs are quiescent
*/
gdb_post_primary_code(gs->lwk_regs, gs->ex_vector, gs->err_code);
+
+ gdb_stop_or_resume_all_except(get_task(ggs->pid, ggs->pid), task->id,
GDB_STOP_TASK);
+ gdb_disable_hw_debug(gs->lwk_regs);
gdb_deactivate_sw_breakpoints(ggs->gdb_break);
//gdb_single_step = 0;
ggs->gdb_contthread = NULL;
-
+ ggs->gdb_usethread = task;
/* Talk to debugger with gdbserial protocol */
error = gdb_serial_stub(ggs, gs);

@@ -1352,7 +1367,7 @@
/* Free gdb_active */
atomic_set(&(ggs->gdb_active), -1);
local_irq_restore(flags);
-
+
return error;
}

@@ -1374,7 +1389,7 @@
struct task_struct *task = (struct task_struct *) priv;
struct gdb_per_process_state * ggs = gdb_htable_lookup(task->aspace->id);

- gdb_stop_or_resume_task(task, GDB_STOP_TASK);
+ gdb_stop_or_resume_all(task, GDB_STOP_TASK);
printk("GDB: attach to task(pid=%d, tid=%d) successfully, waiting for gdb
client to connect\n", task->aspace->id, task->id);
//printk("GDB: attach to task(%d, %d) successfully and wait for gdb
client to connect via %s\n", task->aspace->id, task->id,
ggs->gdb_filep->inode->name);
while(gdbio_get_char(ggs->gdb_filep) != '+');