include/linux/binfmts.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_BINFMTS_H
   3 #define _LINUX_BINFMTS_H
   4
   5 #include <linux/sched.h>
   6 #include <linux/unistd.h>
   7 #include <asm/exec.h>
   8 #include <uapi/linux/binfmts.h>
   9
  10 struct filename;
  11
  12 #define CORENAME_MAX_SIZE 128
  13
  14 /*
  15  * This structure is used to hold the arguments that are used when loading binaries.
  16  */
  17 struct linux_binprm {
  18         char buf[BINPRM_BUF_SIZE];
  19 #ifdef CONFIG_MMU
  20         struct vm_area_struct *vma;
  21         unsigned long vma_pages;
  22 #else
  23 # define MAX_ARG_PAGES  32
  24         struct page *page[MAX_ARG_PAGES];
  25 #endif
  26         struct mm_struct *mm;
  27         unsigned long p; /* current top of mem */
  28         unsigned int
  29                 /*
  30                  * True after the bprm_set_creds hook has been called once
  31                  * (multiple calls can be made via prepare_binprm() for
  32                  * binfmt_script/misc).
  33                  */
  34                 called_set_creds:1,
  35                 /*
  36                  * True if most recent call to the commoncaps bprm_set_creds
  37                  * hook (due to multiple prepare_binprm() calls from the
  38                  * binfmt_script/misc handlers) resulted in elevated
  39                  * privileges.
  40                  */
  41                 cap_elevated:1,
  42                 /*
  43                  * Set by bprm_set_creds hook to indicate a privilege-gaining
  44                  * exec has happened. Used to sanitize execution environment
  45                  * and to set AT_SECURE auxv for glibc.
  46                  */
  47                 secureexec:1;
  48 #ifdef __alpha__
  49         unsigned int taso:1;
  50 #endif
  51         unsigned int recursion_depth; /* only for search_binary_handler() */
  52         struct file * file;
  53         struct cred *cred;      /* new credentials */
  54         int unsafe;             /* how unsafe this exec is (mask of LSM_UNSAFE_*) */
  55         unsigned int per_clear; /* bits to clear in current->personality */
  56         int argc, envc;
  57         const char * filename;  /* Name of binary as seen by procps */
  58         const char * interp;    /* Name of the binary really executed. Most
  59                                    of the time same as filename, but could be
  60                                    different for binfmt_{misc,script} */
  61         unsigned interp_flags;
  62         unsigned interp_data;
  63         unsigned long loader, exec;
  64 } __randomize_layout;
  65
  66 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
  67 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
  68
  69 /* fd of the binary should be passed to the interpreter */
  70 #define BINPRM_FLAGS_EXECFD_BIT 1
  71 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
  72
  73 /* filename of the binary will be inaccessible after exec */
  74 #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
  75 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
  76
  77 /* Function parameter for binfmt->coredump */
  78 struct coredump_params {
  79         const siginfo_t *siginfo;
  80         struct pt_regs *regs;
  81         struct file *file;
  82         unsigned long limit;
  83         unsigned long mm_flags;
  84         loff_t written;
  85         loff_t pos;
  86 };
  87
  88 /*
  89  * This structure defines the functions that are used to load the binary formats that
  90  * linux accepts.
  91  */
  92 struct linux_binfmt {
  93         struct list_head lh;
  94         struct module *module;
  95         int (*load_binary)(struct linux_binprm *);
  96         int (*load_shlib)(struct file *);
  97         int (*core_dump)(struct coredump_params *cprm);
  98         unsigned long min_coredump;     /* minimal dump size */
  99 } __randomize_layout;
 100
 101 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
 102
 103 /* Registration of default binfmt handlers */
 104 static inline void register_binfmt(struct linux_binfmt *fmt)
 105 {
 106         __register_binfmt(fmt, 0);
 107 }
 108 /* Same as above, but adds a new binfmt at the top of the list */
 109 static inline void insert_binfmt(struct linux_binfmt *fmt)
 110 {
 111         __register_binfmt(fmt, 1);
 112 }
 113
 114 extern void unregister_binfmt(struct linux_binfmt *);
 115
 116 extern int prepare_binprm(struct linux_binprm *);
 117 extern int __must_check remove_arg_zero(struct linux_binprm *);
 118 extern int search_binary_handler(struct linux_binprm *);
 119 extern int flush_old_exec(struct linux_binprm * bprm);
 120 extern void setup_new_exec(struct linux_binprm * bprm);
 121 extern void would_dump(struct linux_binprm *, struct file *);
 122
 123 extern int suid_dumpable;
 124
 125 /* Stack area protections */
 126 #define EXSTACK_DEFAULT   0     /* Whatever the arch defaults to */
 127 #define EXSTACK_DISABLE_X 1     /* Disable executable stacks */
 128 #define EXSTACK_ENABLE_X  2     /* Enable executable stacks */
 129
 130 extern int setup_arg_pages(struct linux_binprm * bprm,
 131                            unsigned long stack_top,
 132                            int executable_stack);
 133 extern int transfer_args_to_stack(struct linux_binprm *bprm,
 134                                   unsigned long *sp_location);
 135 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
 136 extern int copy_strings_kernel(int argc, const char *const *argv,
 137                                struct linux_binprm *bprm);
 138 extern int prepare_bprm_creds(struct linux_binprm *bprm);
 139 extern void install_exec_creds(struct linux_binprm *bprm);
 140 extern void set_binfmt(struct linux_binfmt *new);
 141 extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
 142
 143 extern int do_execve(struct filename *,
 144                      const char __user * const __user *,
 145                      const char __user * const __user *);
 146 extern int do_execveat(int, struct filename *,
 147                        const char __user * const __user *,
 148                        const char __user * const __user *,
 149                        int);
 150
 151 #endif /* _LINUX_BINFMTS_H */