kernel/priv.h

   1 #ifndef PRIV_H
   2 #define PRIV_H
   3
   4 /* Declaration of the system privileges structure. It defines flags, system
   5  * call masks, an synchronous alarm timer, I/O privileges, pending hardware
   6  * interrupts and notifications, and so on.
   7  * System processes each get their own structure with properties, whereas all
   8  * user processes share one structure. This setup provides a clear separation
   9  * between common and privileged process fields and is very space efficient.
  10  *
  11  * Changes:
  12  *   Nov 22, 2009  rewrite of privilege management (Cristiano Giuffrida)
  13  *   Jul 01, 2005  Created.  (Jorrit N. Herder)
  14  */
  15 #include <minix/com.h>
  16 #include "const.h"
  17 #include "type.h"
  18
  19 /* Max. number of I/O ranges that can be assigned to a process */
  20 #define NR_IO_RANGE     32
  21
  22 /* Max. number of device memory ranges that can be assigned to a process */
  23 #define NR_MEM_RANGE    10
  24
  25 /* Max. number of IRQs that can be assigned to a process */
  26 #define NR_IRQ  4
  27
  28 struct priv {
  29   proc_nr_t s_proc_nr;          /* number of associated process */
  30   sys_id_t s_id;                /* index of this system structure */
  31   short s_flags;                /* PREEMTIBLE, BILLABLE, etc. */
  32
  33   /* Asynchronous sends */
  34   vir_bytes s_asyntab;          /* addr. of table in process' address space */
  35   size_t s_asynsize;            /* number of elements in table. 0 when not in
  36                                  * use
  37                                  */
  38
  39   short s_trap_mask;            /* allowed system call traps */
  40   sys_map_t s_ipc_to;           /* allowed destination processes */
  41
  42   /* allowed kernel calls */
  43   bitchunk_t s_k_call_mask[SYS_CALL_MASK_SIZE];
  44
  45   sys_map_t s_notify_pending;   /* bit map with pending notifications */
  46   irq_id_t s_int_pending;       /* pending hardware interrupts */
  47   sigset_t s_sig_pending;       /* pending signals */
  48
  49   timer_t s_alarm_timer;        /* synchronous alarm timer */
  50   struct far_mem s_farmem[NR_REMOTE_SEGS];  /* remote memory map */
  51   reg_t *s_stack_guard;         /* stack guard word for kernel tasks */
  52
  53   int s_nr_io_range;            /* allowed I/O ports */
  54   struct io_range s_io_tab[NR_IO_RANGE];
  55
  56   int s_nr_mem_range;           /* allowed memory ranges */
  57   struct mem_range s_mem_tab[NR_MEM_RANGE];
  58
  59   int s_nr_irq;                 /* allowed IRQ lines */
  60   int s_irq_tab[NR_IRQ];
  61   vir_bytes s_grant_table;      /* grant table address of process, or 0 */
  62   int s_grant_entries;          /* no. of entries, or 0 */
  63 };
  64
  65 /* Guard word for task stacks. */
  66 #define STACK_GUARD     ((reg_t) (sizeof(reg_t) == 2 ? 0xBEEF : 0xDEADBEEF))
  67
  68 /* Static privilege id definitions. */
  69 #define NR_STATIC_PRIV_IDS         NR_BOOT_PROCS
  70 #define is_static_priv_id(id)      (id >= 0 && id < NR_STATIC_PRIV_IDS)
  71 #define static_priv_id(n)          (NR_TASKS + (n))
  72
  73 /* Magic system structure table addresses. */
  74 #define BEG_PRIV_ADDR              (&priv[0])
  75 #define END_PRIV_ADDR              (&priv[NR_SYS_PROCS])
  76 #define BEG_STATIC_PRIV_ADDR       BEG_PRIV_ADDR
  77 #define END_STATIC_PRIV_ADDR       (BEG_STATIC_PRIV_ADDR + NR_STATIC_PRIV_IDS)
  78 #define BEG_DYN_PRIV_ADDR          END_STATIC_PRIV_ADDR
  79 #define END_DYN_PRIV_ADDR          END_PRIV_ADDR
  80
  81 #define priv_addr(i)      (ppriv_addr)[(i)]
  82 #define priv_id(rp)       ((rp)->p_priv->s_id)
  83 #define priv(rp)          ((rp)->p_priv)
  84
  85 #define id_to_nr(id)    priv_addr(id)->s_proc_nr
  86 #define nr_to_id(nr)    priv(proc_addr(nr))->s_id
  87
  88 #define may_send_to(rp, nr) (get_sys_bit(priv(rp)->s_ipc_to, nr_to_id(nr)))
  89
  90 /* Privilege management shorthands. */
  91 #define spi_to(n)          (1 << (static_priv_id(n)))
  92 #define unset_usr_to(m)    ((m) & ~(1 << USER_PRIV_ID))
  93
  94 /* The system structures table and pointers to individual table slots. The
  95  * pointers allow faster access because now a process entry can be found by
  96  * indexing the psys_addr array, while accessing an element i requires a
  97  * multiplication with sizeof(struct sys) to determine the address.
  98  */
  99 EXTERN struct priv priv[NR_SYS_PROCS];          /* system properties table */
 100 EXTERN struct priv *ppriv_addr[NR_SYS_PROCS];   /* direct slot pointers */
 101
 102 /* Unprivileged user processes all share the privilege structure of the
 103  * root user process.
 104  * This id must be fixed because it is used to check send mask entries.
 105  */
 106 #define USER_PRIV_ID    static_priv_id(ROOT_USR_PROC_NR)
 107 /* Specifies a null privilege id.
 108  */
 109 #define NULL_PRIV_ID    (-1)
 110
 111 /* Make sure the system can boot. The following sanity check verifies that
 112  * the system privileges table is large enough for the number of processes
 113  * in the boot image.
 114  */
 115 #if (NR_BOOT_PROCS > NR_SYS_PROCS)
 116 #error NR_SYS_PROCS must be larger than NR_BOOT_PROCS
 117 #endif
 118
 119 /*
 120  * Privileges masks used by the kernel.
 121  */
 122 #define IDL_F     (SYS_PROC | BILLABLE) /* idle task is not preemptible as we
 123                                          * don't want it to interfere with the
 124                                          * timer tick interrupt handler code.
 125                                          * Unlike other processes idle task is
 126                                          * handled in a special way and is
 127                                          * preempted always if timer tick occurs
 128                                          * and there is another runnable process
 129                                          */
 130 #define TSK_F     (SYS_PROC)                            /* other kernel tasks */
 131 #define RSYS_F    (SYS_PROC | PREEMPTIBLE)              /* root system proc */
 132 #define DEF_SYS_F (RSYS_F | DYN_PRIV_ID)                /* default sys proc */
 133
 134 /* allowed traps */
 135 #define CSK_T     (1 << RECEIVE)                        /* clock and system */
 136 #define TSK_T     0                                     /* other kernel tasks */
 137 #define RSYS_T    (~0)                                  /* root system proc */
 138 #define DEF_SYS_T RSYS_T                                /* default sys proc */
 139
 140 /* allowed targets */
 141 #define TSK_M     0                                     /* all kernel tasks */
 142 #define RSYS_M    (~0)                                  /* root system proc */
 143 #define DEF_SYS_M unset_usr_to(RSYS_M)                  /* default sys proc */
 144
 145 /* allowed kernel calls */
 146 #define NO_C 0              /* no calls allowed */
 147 #define ALL_C 1             /* all calls allowed */
 148 #define TSK_KC     NO_C                                 /* all kernel tasks */
 149 #define RSYS_KC    ALL_C                                /* root system proc */
 150 #define DEF_SYS_KC RSYS_KC                              /* default sys proc */
 151
 152 #endif /* PRIV_H */