include/linux/seccomp.h

   1 #ifndef _LINUX_SECCOMP_H
   2 #define _LINUX_SECCOMP_H
   3
   4 #include <linux/compiler.h>
   5 #include <linux/types.h>
   6
   7
   8 /* Valid values for seccomp.mode and prctl(PR_SET_SECCOMP, <mode>) */
   9 #define SECCOMP_MODE_DISABLED   0 /* seccomp is not in use. */
  10 #define SECCOMP_MODE_STRICT     1 /* uses hard-coded filter. */
  11 #define SECCOMP_MODE_FILTER     2 /* uses user-supplied filter. */
  12
  13 /*
  14  * All BPF programs must return a 32-bit value.
  15  * The bottom 16-bits are for optional return data.
  16  * The upper 16-bits are ordered from least permissive values to most.
  17  *
  18  * The ordering ensures that a min_t() over composed return values always
  19  * selects the least permissive choice.
  20  */
  21 #define SECCOMP_RET_KILL        0x00000000U /* kill the task immediately */
  22 #define SECCOMP_RET_TRAP        0x00030000U /* disallow and force a SIGSYS */
  23 #define SECCOMP_RET_ERRNO       0x00050000U /* returns an errno */
  24 #define SECCOMP_RET_TRACE       0x7ff00000U /* pass to a tracer or disallow */
  25 #define SECCOMP_RET_ALLOW       0x7fff0000U /* allow */
  26
  27 /* Masks for the return value sections. */
  28 #define SECCOMP_RET_ACTION      0x7fff0000U
  29 #define SECCOMP_RET_DATA        0x0000ffffU
  30
  31 /**
  32  * struct seccomp_data - the format the BPF program executes over.
  33  * @nr: the system call number
  34  * @arch: indicates system call convention as an AUDIT_ARCH_* value
  35  *        as defined in <linux/audit.h>.
  36  * @instruction_pointer: at the time of the system call.
  37  * @args: up to 6 system call arguments always stored as 64-bit values
  38  *        regardless of the architecture.
  39  */
  40 struct seccomp_data {
  41         int nr;
  42         __u32 arch;
  43         __u64 instruction_pointer;
  44         __u64 args[6];
  45 };
  46
  47 #ifdef __KERNEL__
  48 #ifdef CONFIG_SECCOMP
  49
  50 #include <linux/thread_info.h>
  51 #include <asm/seccomp.h>
  52
  53 struct seccomp_filter;
  54 /**
  55  * struct seccomp - the state of a seccomp'ed process
  56  *
  57  * @mode:  indicates one of the valid values above for controlled
  58  *         system calls available to a process.
  59  * @filter: The metadata and ruleset for determining what system calls
  60  *          are allowed for a task.
  61  *
  62  *          @filter must only be accessed from the context of current as there
  63  *          is no locking.
  64  */
  65 struct seccomp {
  66         int mode;
  67         struct seccomp_filter *filter;
  68 };
  69
  70 extern int __secure_computing(int);
  71 static inline int secure_computing(int this_syscall)
  72 {
  73         if (unlikely(test_thread_flag(TIF_SECCOMP)))
  74                 return  __secure_computing(this_syscall);
  75         return 0;
  76 }
  77
  78 /* A wrapper for architectures supporting only SECCOMP_MODE_STRICT. */
  79 static inline void secure_computing_strict(int this_syscall)
  80 {
  81         BUG_ON(secure_computing(this_syscall) != 0);
  82 }
  83
  84 extern long prctl_get_seccomp(void);
  85 extern long prctl_set_seccomp(unsigned long, char __user *);
  86
  87 static inline int seccomp_mode(struct seccomp *s)
  88 {
  89         return s->mode;
  90 }
  91
  92 #else /* CONFIG_SECCOMP */
  93
  94 #include <linux/errno.h>
  95
  96 struct seccomp { };
  97 struct seccomp_filter { };
  98
  99 static inline int secure_computing(int this_syscall) { return 0; }
 100 static inline void secure_computing_strict(int this_syscall) { return; }
 101
 102 static inline long prctl_get_seccomp(void)
 103 {
 104         return -EINVAL;
 105 }
 106
 107 static inline long prctl_set_seccomp(unsigned long arg2, char __user *arg3)
 108 {
 109         return -EINVAL;
 110 }
 111
 112 static inline int seccomp_mode(struct seccomp *s)
 113 {
 114         return 0;
 115 }
 116 #endif /* CONFIG_SECCOMP */
 117
 118 #ifdef CONFIG_SECCOMP_FILTER
 119 extern void put_seccomp_filter(struct task_struct *tsk);
 120 extern void get_seccomp_filter(struct task_struct *tsk);
 121 extern u32 seccomp_bpf_load(int off);
 122 #else  /* CONFIG_SECCOMP_FILTER */
 123 static inline void put_seccomp_filter(struct task_struct *tsk)
 124 {
 125         return;
 126 }
 127 static inline void get_seccomp_filter(struct task_struct *tsk)
 128 {
 129         return;
 130 }
 131 #endif /* CONFIG_SECCOMP_FILTER */
 132 #endif /* __KERNEL__ */
 133 #endif /* _LINUX_SECCOMP_H */