include/linux/binfmts.h

   1 #ifndef _LINUX_BINFMTS_H
   2 #define _LINUX_BINFMTS_H
   3
   4 #include <linux/capability.h>
   5
   6 struct pt_regs;
   7
   8 /*
   9  * These are the maximum length and maximum number of strings passed to the
  10  * execve() system call.  MAX_ARG_STRLEN is essentially random but serves to
  11  * prevent the kernel from being unduly impacted by misaddressed pointers.
  12  * MAX_ARG_STRINGS is chosen to fit in a signed 32-bit integer.
  13  */
  14 #define MAX_ARG_STRLEN (PAGE_SIZE * 32)
  15 #define MAX_ARG_STRINGS 0x7FFFFFFF
  16
  17 /* sizeof(linux_binprm->buf) */
  18 #define BINPRM_BUF_SIZE 128
  19
  20 #ifdef __KERNEL__
  21 #include <linux/list.h>
  22
  23 #define CORENAME_MAX_SIZE 128
  24
  25 /*
  26  * This structure is used to hold the arguments that are used when loading binaries.
  27  */
  28 struct linux_binprm {
  29         char buf[BINPRM_BUF_SIZE];
  30 #ifdef CONFIG_MMU
  31         struct vm_area_struct *vma;
  32         unsigned long vma_pages;
  33 #else
  34 # define MAX_ARG_PAGES  32
  35         struct page *page[MAX_ARG_PAGES];
  36 #endif
  37         struct mm_struct *mm;
  38         unsigned long p; /* current top of mem */
  39         unsigned int
  40                 cred_prepared:1,/* true if creds already prepared (multiple
  41                                  * preps happen for interpreters) */
  42                 cap_effective:1;/* true if has elevated effective capabilities,
  43                                  * false if not; except for init which inherits
  44                                  * its parent's caps anyway */
  45 #ifdef __alpha__
  46         unsigned int taso:1;
  47 #endif
  48         unsigned int recursion_depth;
  49         struct file * file;
  50         struct cred *cred;      /* new credentials */
  51         int unsafe;             /* how unsafe this exec is (mask of LSM_UNSAFE_*) */
  52         unsigned int per_clear; /* bits to clear in current->personality */
  53         int argc, envc;
  54         const char * filename;  /* Name of binary as seen by procps */
  55         const char * interp;    /* Name of the binary really executed. Most
  56                                    of the time same as filename, but could be
  57                                    different for binfmt_{misc,script} */
  58         unsigned interp_flags;
  59         unsigned interp_data;
  60         unsigned long loader, exec;
  61 };
  62
  63 extern void acct_arg_size(struct linux_binprm *bprm, unsigned long pages);
  64 extern struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
  65                                         int write);
  66
  67 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
  68 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
  69
  70 /* fd of the binary should be passed to the interpreter */
  71 #define BINPRM_FLAGS_EXECFD_BIT 1
  72 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
  73
  74 #define BINPRM_MAX_RECURSION 4
  75
  76 /* Function parameter for binfmt->coredump */
  77 struct coredump_params {
  78         long signr;
  79         struct pt_regs *regs;
  80         struct file *file;
  81         unsigned long limit;
  82         unsigned long mm_flags;
  83 };
  84
  85 /*
  86  * This structure defines the functions that are used to load the binary formats that
  87  * linux accepts.
  88  */
  89 struct linux_binfmt {
  90         struct list_head lh;
  91         struct module *module;
  92         int (*load_binary)(struct linux_binprm *, struct  pt_regs * regs);
  93         int (*load_shlib)(struct file *);
  94         int (*core_dump)(struct coredump_params *cprm);
  95         unsigned long min_coredump;     /* minimal dump size */
  96 };
  97
  98 extern int __register_binfmt(struct linux_binfmt *fmt, int insert);
  99
 100 /* Registration of default binfmt handlers */
 101 static inline int register_binfmt(struct linux_binfmt *fmt)
 102 {
 103         return __register_binfmt(fmt, 0);
 104 }
 105 /* Same as above, but adds a new binfmt at the top of the list */
 106 static inline int insert_binfmt(struct linux_binfmt *fmt)
 107 {
 108         return __register_binfmt(fmt, 1);
 109 }
 110
 111 extern void unregister_binfmt(struct linux_binfmt *);
 112
 113 extern int prepare_binprm(struct linux_binprm *);
 114 extern int __must_check remove_arg_zero(struct linux_binprm *);
 115 extern int search_binary_handler(struct linux_binprm *, struct pt_regs *);
 116 extern int flush_old_exec(struct linux_binprm * bprm);
 117 extern void setup_new_exec(struct linux_binprm * bprm);
 118
 119 extern int suid_dumpable;
 120 #define SUID_DUMP_DISABLE       0       /* No setuid dumping */
 121 #define SUID_DUMP_USER          1       /* Dump as user of process */
 122 #define SUID_DUMP_ROOT          2       /* Dump as root */
 123
 124 /* Stack area protections */
 125 #define EXSTACK_DEFAULT   0     /* Whatever the arch defaults to */
 126 #define EXSTACK_DISABLE_X 1     /* Disable executable stacks */
 127 #define EXSTACK_ENABLE_X  2     /* Enable executable stacks */
 128
 129 extern int setup_arg_pages(struct linux_binprm * bprm,
 130                            unsigned long stack_top,
 131                            int executable_stack);
 132 extern int bprm_mm_init(struct linux_binprm *bprm);
 133 extern int copy_strings_kernel(int argc, const char *const *argv,
 134                                struct linux_binprm *bprm);
 135 extern int prepare_bprm_creds(struct linux_binprm *bprm);
 136 extern void install_exec_creds(struct linux_binprm *bprm);
 137 extern void do_coredump(long signr, int exit_code, struct pt_regs *regs);
 138 extern void set_binfmt(struct linux_binfmt *new);
 139 extern void free_bprm(struct linux_binprm *);
 140
 141 #endif /* __KERNEL__ */
 142 #endif /* _LINUX_BINFMTS_H */