bitkeeper revision 1.1726.3.1 (42c07007i9Bkz3ggP_PXIksWaGD1Eg)

add framework for debugging processes

tools/debugger/pdb/linux-2.6-module/module.c

@@ -0,0 +1,226 @@
+
+/*
+ * module.c
+ *
+ * Handles initial registration with pdb when the pdb module starts up
+ * and cleanup when the module goes away (sortof :)
+ * Also receives each request from pdb in domain 0 and dispatches to the
+ * appropriate debugger function.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+#include <asm-xen/evtchn.h>
+#include <asm-xen/ctrl_if.h>
+#include <asm-xen/hypervisor.h>
+#include <asm-xen/xen-public/io/domain_controller.h>
+#include <asm-xen/xen-public/xen.h>
+
+#include <asm-xen/xen-public/io/ring.h>
+
+#include "pdb_module.h"
+
+#define PDB_RING_SIZE __RING_SIZE((pdb_sring_t *)0, PAGE_SIZE)
+
+static pdb_back_ring_t pdb_ring;
+static unsigned int    pdb_evtchn;
+static unsigned int    pdb_irq;
+
+/*
+ * send response to a pdb request
+ */
+static void
+pdb_send_response (pdb_response_t *response)
+{
+    pdb_response_t *resp;
+
+    resp = RING_GET_RESPONSE(&pdb_ring, pdb_ring.rsp_prod_pvt);
+
+    memcpy(resp, response, sizeof(pdb_response_t));
+    
+    wmb();                 /* Ensure other side can see the response fields. */
+    pdb_ring.rsp_prod_pvt++;
+    RING_PUSH_RESPONSES(&pdb_ring);
+    notify_via_evtchn(pdb_evtchn);
+    return;
+}
+
+/*
+ * handle a debug command from the front end
+ */
+static void
+pdb_process_request (pdb_request_t *request)
+{
+    pdb_response_t resp;
+
+    switch (request->operation)
+    {
+    case PDB_OPCODE_ATTACH :
+        pdb_attach(request->process);
+        resp.status = PDB_RESPONSE_OKAY;
+        break;
+    case PDB_OPCODE_DETACH :
+        pdb_detach(request->process);
+        resp.status = PDB_RESPONSE_OKAY;
+        break;
+    case PDB_OPCODE_RD_REG :
+        pdb_read_register(request->process, &request->u.rd_reg, 
+                          (unsigned long *)&resp.value);
+        resp.status = PDB_RESPONSE_OKAY;
+        break;
+    case PDB_OPCODE_WR_REG :
+        pdb_write_register(request->process, &request->u.wr_reg);
+        resp.status = PDB_RESPONSE_OKAY;
+        break;
+    default:
+        printk("(pdb) unknown request operation %d\n", request->operation);
+        resp.status = PDB_RESPONSE_ERROR;
+    }
+        
+    resp.operation = request->operation;
+            
+    pdb_send_response (&resp);
+    return;
+}
+
+/*
+ * receive a pdb request
+ */
+static irqreturn_t
+pdb_interrupt (int irq, void *dev_id, struct pt_regs *ptregs)
+{
+    pdb_request_t *req;
+    RING_IDX i, rp;
+
+    rp = pdb_ring.sring->req_prod;
+    rmb();
+
+    for ( i = pdb_ring.req_cons; 
+          (i != rp) && !RING_REQUEST_CONS_OVERFLOW(&pdb_ring, i);
+          i++ )
+    {
+        req = RING_GET_REQUEST(&pdb_ring, i);
+        pdb_process_request(req);
+
+    }
+    pdb_ring.req_cons = i;
+
+    return IRQ_HANDLED;
+}
+
+
+static void
+pdb_send_connection_status(int status, memory_t ring)
+{
+    ctrl_msg_t cmsg = 
+    {
+        .type = CMSG_DEBUG,
+        .subtype = CMSG_DEBUG_CONNECTION_STATUS,
+        .length  = sizeof(pdb_connection_t),
+    };
+    pdb_connection_t *conn = (pdb_connection_t *)cmsg.msg;
+
+    conn->status = status;
+    conn->ring = ring;
+    conn->evtchn = 0;
+
+    ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
+}
+
+
+/*
+ * this is called each time a message is received on the control channel
+ */
+static void
+pdb_ctrlif_rx(ctrl_msg_t *msg, unsigned long id)
+{
+printk ("pdb ctrlif rx\n");
+
+    switch (msg->subtype)
+    {
+    case CMSG_DEBUG_CONNECTION_STATUS:
+        /* initialize event channel created by the pdb server */
+
+        pdb_evtchn = ((pdb_connection_p) msg->msg)->evtchn;
+        pdb_irq = bind_evtchn_to_irq(pdb_evtchn);
+
+        if ( request_irq(pdb_irq, pdb_interrupt, 
+                         SA_SAMPLE_RANDOM, "pdb", NULL) )
+        {
+            printk("(pdb) request irq failed: %d %d\n", pdb_evtchn, pdb_irq);
+        }
+        break;
+
+    default:
+        printk ("(pdb) unknown xcs control message: %d\n", msg->subtype);
+        break;
+    }
+
+    return;
+}
+
+static int __init 
+pdb_initialize(void)
+{
+    pdb_sring_t *sring;
+
+    printk("----\npdb initialize   %s %s\n", __DATE__, __TIME__);
+
+    /*
+    if ( xen_start_info.flags & SIF_INITDOMAIN )
+        return 1;
+    */
+
+    (void)ctrl_if_register_receiver(CMSG_DEBUG, pdb_ctrlif_rx,
+                                    CALLBACK_IN_BLOCKING_CONTEXT);
+
+    /* rings */
+    sring = (pdb_sring_t *)__get_free_page(GFP_KERNEL);
+    SHARED_RING_INIT(sring);
+    BACK_RING_INIT(&pdb_ring, sring, PAGE_SIZE);
+ 
+    /* notify pdb in dom 0 */
+    pdb_send_connection_status(PDB_CONNECTION_STATUS_UP, 
+                               virt_to_machine(pdb_ring.sring) >> PAGE_SHIFT);
+
+    return 0;
+}
+
+static void __exit
+pdb_terminate(void)
+{
+    printk("pdb cleanup\n");
+
+    (void)ctrl_if_unregister_receiver(CMSG_DEBUG, pdb_ctrlif_rx);
+
+    if (pdb_irq)
+    {
+        free_irq(pdb_irq, NULL);
+        pdb_irq = 0;
+    }
+
+    if (pdb_evtchn)
+    {
+        unbind_evtchn_from_irq(pdb_evtchn); 
+        pdb_evtchn = 0;
+    }
+
+    pdb_send_connection_status(PDB_CONNECTION_STATUS_DOWN, 0);
+}
+
+
+module_init(pdb_initialize);
+module_exit(pdb_terminate);
+
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
+