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 <minix/const.h>
  17 #include "const.h"
  18 #include "type.h"
  19
  20 /* Max. number of I/O ranges that can be assigned to a process */
  21 #define NR_IO_RANGE     32
  22
  23 /* Max. number of device memory ranges that can be assigned to a process */
  24 #define NR_MEM_RANGE    10
  25
  26 /* Max. number of IRQs that can be assigned to a process */
  27 #define NR_IRQ  4
  28
  29 struct priv {
  30   proc_nr_t s_proc_nr;          /* number of associated process */
  31   sys_id_t s_id;                /* index of this system structure */
  32   short s_flags;                /* PREEMTIBLE, BILLABLE, etc. */
  33
  34   /* Asynchronous sends */
  35   vir_bytes s_asyntab;          /* addr. of table in process' address space */
  36   size_t s_asynsize;            /* number of elements in table. 0 when not in
  37                                  * use
  38                                  */
  39
  40   short s_trap_mask;            /* allowed system call traps */
  41   sys_map_t s_ipc_to;           /* allowed destination processes */
  42
  43   /* allowed kernel calls */
  44   bitchunk_t s_k_call_mask[SYS_CALL_MASK_SIZE];
  45
  46   endpoint_t s_sig_mgr;         /* signal manager for system signals */
  47   sys_map_t s_notify_pending;   /* bit map with pending notifications */
  48   irq_id_t s_int_pending;       /* pending hardware interrupts */
  49   sigset_t s_sig_pending;       /* pending signals */
  50
  51   timer_t s_alarm_timer;        /* synchronous alarm timer */
  52   struct far_mem s_farmem[NR_REMOTE_SEGS];  /* remote memory map */
  53   reg_t *s_stack_guard;         /* stack guard word for kernel tasks */
  54
  55   int s_nr_io_range;            /* allowed I/O ports */
  56   struct io_range s_io_tab[NR_IO_RANGE];
  57
  58   int s_nr_mem_range;           /* allowed memory ranges */
  59   struct mem_range s_mem_tab[NR_MEM_RANGE];
  60
  61   int s_nr_irq;                 /* allowed IRQ lines */
  62   int s_irq_tab[NR_IRQ];
  63   vir_bytes s_grant_table;      /* grant table address of process, or 0 */
  64   int s_grant_entries;          /* no. of entries, or 0 */
  65 };
  66
  67 /* Guard word for task stacks. */
  68 #define STACK_GUARD     ((reg_t) (sizeof(reg_t) == 2 ? 0xBEEF : 0xDEADBEEF))
  69
  70 /* Static privilege id definitions. */
  71 #define NR_STATIC_PRIV_IDS         NR_BOOT_PROCS
  72 #define is_static_priv_id(id)      (id >= 0 && id < NR_STATIC_PRIV_IDS)
  73 #define static_priv_id(n)          (NR_TASKS + (n))
  74
  75 /* Magic system structure table addresses. */
  76 #define BEG_PRIV_ADDR              (&priv[0])
  77 #define END_PRIV_ADDR              (&priv[NR_SYS_PROCS])
  78 #define BEG_STATIC_PRIV_ADDR       BEG_PRIV_ADDR
  79 #define END_STATIC_PRIV_ADDR       (BEG_STATIC_PRIV_ADDR + NR_STATIC_PRIV_IDS)
  80 #define BEG_DYN_PRIV_ADDR          END_STATIC_PRIV_ADDR
  81 #define END_DYN_PRIV_ADDR          END_PRIV_ADDR
  82
  83 #define priv_addr(i)      (ppriv_addr)[(i)]
  84 #define priv_id(rp)       ((rp)->p_priv->s_id)
  85 #define priv(rp)          ((rp)->p_priv)
  86
  87 #define id_to_nr(id)    priv_addr(id)->s_proc_nr
  88 #define nr_to_id(nr)    priv(proc_addr(nr))->s_id
  89
  90 #define may_send_to(rp, nr) (get_sys_bit(priv(rp)->s_ipc_to, nr_to_id(nr)))
  91
  92 /* Privilege management shorthands. */
  93 #define spi_to(n)          (1 << (static_priv_id(n)))
  94 #define unset_usr_to(m)    ((m) & ~(1 << USER_PRIV_ID))
  95
  96 /* The system structures table and pointers to individual table slots. The
  97  * pointers allow faster access because now a process entry can be found by
  98  * indexing the psys_addr array, while accessing an element i requires a
  99  * multiplication with sizeof(struct sys) to determine the address.
 100  */
 101 EXTERN struct priv priv[NR_SYS_PROCS];          /* system properties table */
 102 EXTERN struct priv *ppriv_addr[NR_SYS_PROCS];   /* direct slot pointers */
 103
 104 /* Unprivileged user processes all share the privilege structure of the
 105  * root user process.
 106  * This id must be fixed because it is used to check send mask entries.
 107  */
 108 #define USER_PRIV_ID    static_priv_id(ROOT_USR_PROC_NR)
 109 /* Specifies a null privilege id.
 110  */
 111 #define NULL_PRIV_ID    (-1)
 112
 113 /* Make sure the system can boot. The following sanity check verifies that
 114  * the system privileges table is large enough for the number of processes
 115  * in the boot image.
 116  */
 117 #if (NR_BOOT_PROCS > NR_SYS_PROCS)
 118 #error NR_SYS_PROCS must be larger than NR_BOOT_PROCS
 119 #endif
 120
 121 /*
 122  * Privileges masks used by the kernel.
 123  */
 124 #define IDL_F     (SYS_PROC | BILLABLE) /* idle task is not preemptible as we
 125                                          * don't want it to interfere with the
 126                                          * timer tick interrupt handler code.
 127                                          * Unlike other processes idle task is
 128                                          * handled in a special way and is
 129                                          * preempted always if timer tick occurs
 130                                          * and there is another runnable process
 131                                          */
 132 #define TSK_F     (SYS_PROC)                            /* other kernel tasks */
 133 #define RSYS_F    (SYS_PROC | PREEMPTIBLE)              /* root system proc */
 134 #define DEF_SYS_F (RSYS_F | DYN_PRIV_ID)                /* default sys proc */
 135
 136 /* allowed traps */
 137 #define CSK_T     (1 << RECEIVE)                        /* clock and system */
 138 #define TSK_T     0                                     /* other kernel tasks */
 139 #define RSYS_T    (~0)                                  /* root system proc */
 140 #define DEF_SYS_T RSYS_T                                /* default sys proc */
 141
 142 /* allowed targets */
 143 #define TSK_M     0                                     /* all kernel tasks */
 144 #define RSYS_M    (~0)                                  /* root system proc */
 145 #define DEF_SYS_M unset_usr_to(RSYS_M)                  /* default sys proc */
 146
 147 /* allowed kernel calls */
 148 #define NO_C 0              /* no calls allowed */
 149 #define ALL_C 1             /* all calls allowed */
 150 #define TSK_KC     NO_C                                 /* all kernel tasks */
 151 #define RSYS_KC    ALL_C                                /* root system proc */
 152 #define DEF_SYS_KC RSYS_KC                              /* default sys proc */
 153
 154 /* signal manager */
 155 #define RSYS_SM    ROOT_SYS_PROC_NR                     /* root system proc */
 156 #define DEF_SYS_SM ROOT_SYS_PROC_NR                     /* default sys proc */
 157
 158 #endif /* PRIV_H */