gdbstub initial code, v7

2010-08-30 Thread Oleg Nesterov
Changes:

- report signals. A bit more code changes than I expected.

- implement QPassSignals, trivial.

Note: $CSIG is not supported yet, and I am not sure I understand
how it should work. Next time...

#include linux/module.h
#include linux/proc_fs.h
#include linux/utrace.h
#include linux/poll.h
#include linux/mm.h
#include linux/regset.h
#include asm/uaccess.h

static int o_remote_debug;
module_param_named(echo, o_remote_debug, bool, 0);

#define BUFFER_SIZE 1024
#define PACKET_SIZE 1024

struct pbuf {
char*cur, *pkt;
charbuf[BUFFER_SIZE];
};

static inline void pb_init(struct pbuf *pb)
{
pb-cur = pb-buf;
pb-pkt = NULL;
}

enum {
U_STOP_IDLE = 0,
U_STOP_PENDING,
U_STOP_SENT,
};

struct ugdb {
struct list_headu_processes;
struct list_headu_stopped;

int u_stop_state;

struct mutexu_mutex;
spinlock_t  u_slock;

struct ugdb_thread
*u_cur_tinfo,
*u_cur_hg,
*u_cur_hc;

wait_queue_head_t   u_wait;

int u_err;

struct pbuf u_pbuf;
charu_cbuf[PACKET_SIZE];
int u_clen;

sigset_tu_sig_ign;

unsigned int
u_no_ack:1,
u_allstop:1;
};

static inline void ugdb_ck_stopped(struct ugdb *ugdb)
{
spin_lock(ugdb-u_slock);
WARN_ON(!list_empty(ugdb-u_stopped) 
ugdb-u_stop_state == U_STOP_IDLE);
WARN_ON(list_empty(ugdb-u_stopped) 
ugdb-u_stop_state == U_STOP_PENDING);
spin_unlock(ugdb-u_slock);
}

static struct ugdb *ugdb_create(void)
{
struct ugdb *ugdb;
int err;

err = -ENODEV;
// XXX: ugly. proc_reg_open() should take care.
if (!try_module_get(THIS_MODULE))
goto out;

err = -ENOMEM;
ugdb = kzalloc(sizeof(*ugdb), GFP_KERNEL);
if (!ugdb)
goto put_module;

INIT_LIST_HEAD(ugdb-u_processes);
INIT_LIST_HEAD(ugdb-u_stopped);

mutex_init(ugdb-u_mutex);
spin_lock_init(ugdb-u_slock);

init_waitqueue_head(ugdb-u_wait);

pb_init(ugdb-u_pbuf);

return ugdb;

put_module:
module_put(THIS_MODULE);
out:
return ERR_PTR(err);
}

#define P_DETACHING (1  1)
#define P_ZOMBIE(1  2)

struct ugdb_process {
int p_pid;
int p_state;

struct list_headp_threads;

struct ugdb *p_ugdb;
struct list_headp_processes;
};

static inline bool process_alive(struct ugdb_process *process)
{
return !(process-p_state  P_ZOMBIE);
}

static inline void mark_process_dead(struct ugdb_process *process)
{
process-p_state |= P_ZOMBIE;
}

static struct ugdb_process *ugdb_create_process(struct ugdb *ugdb, int pid_nr)
{
struct ugdb_process *process;

process = kzalloc(sizeof(*process), GFP_KERNEL);
if (!process)
return NULL;

process-p_pid = pid_nr;
process-p_ugdb = ugdb;
INIT_LIST_HEAD(process-p_threads);
list_add_tail(process-p_processes, ugdb-u_processes);

return process;
}

#define T_STOP_RUN  0
#define T_STOP_REQ  (1  0)/* requested by gdb */
#define T_STOP_ALL  (1  1)/* vCont;c:pX.-1, for report_clone */
#define T_STOP_ACK  (1  2)/* visible to vStopped */
#define T_STOP_STOPPED  (1  3)/* reported as stopped to gdb */
/* TASK_TRACED + deactivated ? */

#define T_EV_NONE   0
#define T_EV_EXIT   (1  24)
#define T_EV_SIGN   (2  24)

#define T_EV_TYPE(event)((0xff  24)  (event))
#define T_EV_DATA(event)(~(0xff  24)  (event))

struct ugdb_thread {
int t_tid;
int t_stop_state;
int t_stop_event;

struct ugdb *t_ugdb;
struct ugdb_process *t_process;

struct list_headt_threads;
struct list_headt_stopped;

struct pid  *t_spid;

struct utrace_engine*t_engine;
};

static inline bool thread_alive(struct ugdb_thread *thread)
{
WARN_ON((thread-t_tid != 0) != process_alive(thread-t_process));

return thread-t_tid != 0;
}

static inline void mark_thread_dead(struct ugdb_thread *thread)
{
mark_process_dead(thread-t_process);
thread-t_tid = 0;
}

/*
 * The thread should be alive, and it can't pass ugdb_report_death()
 * if the caller holds ugdb-u_mutex. However 

Re: gdbstub initial code, v7

2010-08-30 Thread Jan Kratochvil
On Mon, 30 Aug 2010 20:58:50 +0200, Oleg Nesterov wrote:
   - report signals. A bit more code changes than I expected.

BTW not sure if it is already the right time for it but to keep ugdb on-par
with my linux-nat's re-post today (still not accepted in FSF GDB)
[0/9]#2 Fix lost siginfo_t
http://sourceware.org/ml/gdb-patches/2010-08/msg00480.html

ugdb should support qXfer:siginfo, currently accessible only via $_siginfo
print/set, though.


Thanks,
Jan