src/add-ons/kernel/debugger/run_on_exit/run_on_exit.cpp

   1 /*
   2  * Copyright 2009, Michael Lotz, mmlr@mlotz.ch
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #include <debug.h>
   6 #include <signal.h>
   7 #include <string.h>
   8 #include <image.h>
   9
  10
  11 static sem_id sRequestSem = -1;
  12 static char sCommandBuffer[1024];
  13 static uint32 sCommandOffset = 0;
  14 static uint32 sCommandCount = 0;
  15
  16
  17 static int32
  18 run_on_exit_loop(void *data)
  19 {
  20         while (true) {
  21                 if (acquire_sem(sRequestSem) != B_OK)
  22                         break;
  23
  24                 char *pointer = sCommandBuffer;
  25                 while (sCommandCount > 0) {
  26                         uint8 argCount = (uint8)pointer[0];
  27                         pointer++;
  28
  29                         const char *args[argCount];
  30                         for (uint8 i = 0; i < argCount; i++) {
  31                                 args[i] = pointer;
  32                                 uint32 length = strlen(pointer);
  33                                 pointer += length + 1;
  34                         }
  35
  36                         thread_id thread = load_image(argCount, args, NULL);
  37                         if (thread >= B_OK)
  38                                 resume_thread(thread);
  39                         sCommandCount--;
  40                 }
  41
  42                 sCommandOffset = 0;
  43         }
  44
  45         return 0;
  46 }
  47
  48
  49 static int
  50 add_run_on_exit_command(int argc, char **argv)
  51 {
  52         if (argc < 2 || strcmp(argv[1], "--help") == 0) {
  53                 print_debugger_command_usage(argv[0]);
  54                 return 0;
  55         }
  56
  57         if (argc > 256) {
  58                 kprintf("too many arguments\n");
  59                 return 0;
  60         }
  61
  62         size_t totalLength = 1;
  63         for (int32 i = 1; i < argc; i++)
  64                 totalLength += strlen(argv[i]) + 1;
  65
  66         if (sCommandOffset + totalLength > sizeof(sCommandBuffer)) {
  67                 kprintf("no space left in command buffer\n");
  68                 return 0;
  69         }
  70
  71         char *pointer = sCommandBuffer + sCommandOffset;
  72         *pointer++ = (char)(argc - 1);
  73
  74         for (int32 i = 1; i < argc; i++) {
  75                 strcpy(pointer, argv[i]);
  76                 pointer += strlen(argv[i]) + 1;
  77         }
  78
  79         sCommandOffset += totalLength;
  80         sCommandCount++;
  81         return 0;
  82 }
  83
  84
  85 static void
  86 exit_debugger()
  87 {
  88         if (sCommandCount > 0)
  89                 release_sem_etc(sRequestSem, 1, B_DO_NOT_RESCHEDULE);
  90 }
  91
  92
  93 static status_t
  94 std_ops(int32 op, ...)
  95 {
  96         if (op == B_MODULE_INIT) {
  97                 sRequestSem = create_sem(0, "run_on_exit_request");
  98                 if (sRequestSem < B_OK)
  99                         return sRequestSem;
 100
 101                 thread_id thread = spawn_kernel_thread(&run_on_exit_loop,
 102                         "run_on_exit_loop", B_NORMAL_PRIORITY, NULL);
 103                 if (thread < B_OK)
 104                         return thread;
 105
 106                 resume_thread(thread);
 107
 108                 add_debugger_command_etc("on_exit", &add_run_on_exit_command,
 109                         "Adds a command to be run when leaving the kernel debugger",
 110                         "<command> [<arguments>]\n"
 111                         "Adds a command to be run when leaving the kernel debugger.\n", 0);
 112
 113                 return B_OK;
 114         } else if (op == B_MODULE_UNINIT) {
 115                 remove_debugger_command("on_exit", &add_run_on_exit_command);
 116                 // deleting the sem will also cause the thread to exit
 117                 delete_sem(sRequestSem);
 118                 sRequestSem = -1;
 119                 return B_OK;
 120         }
 121
 122         return B_BAD_VALUE;
 123 }
 124
 125
 126 static struct debugger_module_info sModuleInfo = {
 127         {
 128                 "debugger/run_on_exit/v1",
 129                 B_KEEP_LOADED,
 130                 &std_ops
 131         },
 132
 133         NULL,
 134         exit_debugger,
 135         NULL,
 136         NULL
 137 };
 138
 139 module_info *modules[] = {
 140         (module_info *)&sModuleInfo,
 141         NULL
 142 };