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 #ifdef CONFIG_MMU
  19         struct vm_area_struct *vma;
  20         unsigned long vma_pages;
  21 #else
  22 # define MAX_ARG_PAGES  32
  23         struct page *page[MAX_ARG_PAGES];
  24 #endif
  25         struct mm_struct *mm;
  26         unsigned long p; /* current top of mem */
  27         unsigned long argmin; /* rlimit marker for copy_strings() */
  28         unsigned int
  29                 /* Should an execfd be passed to userspace? */
  30                 have_execfd:1,
  31
  32                 /* Use the creds of a script (see binfmt_misc) */
  33                 execfd_creds:1,
  34                 /*
  35                  * Set by bprm_creds_for_exec hook to indicate a
  36                  * privilege-gaining exec has happened. Used to set
  37                  * AT_SECURE auxv for glibc.
  38                  */
  39                 secureexec:1,
  40                 /*
  41                  * Set when errors can no longer be returned to the
  42                  * original userspace.
  43                  */
  44                 point_of_no_return:1;
  45 #ifdef __alpha__
  46         unsigned int taso:1;
  47 #endif
  48         struct file *executable; /* Executable to pass to the interpreter */
  49         struct file *interpreter;
  50         struct file *file;
  51         struct cred *cred;      /* new credentials */
  52         int unsafe;             /* how unsafe this exec is (mask of LSM_UNSAFE_*) */
  53         unsigned int per_clear; /* bits to clear in current->personality */
  54         int argc, envc;
  55         const char *filename;   /* Name of binary as seen by procps */
  56         const char *interp;     /* Name of the binary really executed. Most
  57                                    of the time same as filename, but could be
  58                                    different for binfmt_{misc,script} */
  59         const char *fdpath;     /* generated filename for execveat */
  60         unsigned interp_flags;
  61         int execfd;             /* File descriptor of the executable */
  62         unsigned long loader, exec;
  63
  64         struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */
  65
  66         char buf[BINPRM_BUF_SIZE];
  67 } __randomize_layout;
  68
  69 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
  70 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
  71
  72 /* filename of the binary will be inaccessible after exec */
  73 #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
  74 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
  75
  76 /* preserve argv0 for the interpreter  */
  77 #define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
  78 #define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
  79
  80 /* Function parameter for binfmt->coredump */
  81 struct coredump_params {
  82         const kernel_siginfo_t *siginfo;
  83         struct pt_regs *regs;
  84         struct file *file;
  85         unsigned long limit;
  86         unsigned long mm_flags;
  87         loff_t written;
  88         loff_t pos;
  89         loff_t to_skip;
  90 };
  91
  92 /*
  93  * This structure defines the functions that are used to load the binary formats that
  94  * linux accepts.
  95  */
  96 struct linux_binfmt {
  97         struct list_head lh;
  98         struct module *module;
  99         int (*load_binary)(struct linux_binprm *);
 100         int (*load_shlib)(struct file *);
 101         int (*core_dump)(struct coredump_params *cprm);
 102         unsigned long min_coredump;     /* minimal dump size */
 103 } __randomize_layout;
 104
 105 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
 106
 107 /* Registration of default binfmt handlers */
 108 static inline void register_binfmt(struct linux_binfmt *fmt)
 109 {
 110         __register_binfmt(fmt, 0);
 111 }
 112 /* Same as above, but adds a new binfmt at the top of the list */
 113 static inline void insert_binfmt(struct linux_binfmt *fmt)
 114 {
 115         __register_binfmt(fmt, 1);
 116 }
 117
 118 extern void unregister_binfmt(struct linux_binfmt *);
 119
 120 extern int __must_check remove_arg_zero(struct linux_binprm *);
 121 extern int begin_new_exec(struct linux_binprm * bprm);
 122 extern void setup_new_exec(struct linux_binprm * bprm);
 123 extern void finalize_exec(struct linux_binprm *bprm);
 124 extern void would_dump(struct linux_binprm *, struct file *);
 125
 126 extern int suid_dumpable;
 127
 128 /* Stack area protections */
 129 #define EXSTACK_DEFAULT   0     /* Whatever the arch defaults to */
 130 #define EXSTACK_DISABLE_X 1     /* Disable executable stacks */
 131 #define EXSTACK_ENABLE_X  2     /* Enable executable stacks */
 132
 133 extern int setup_arg_pages(struct linux_binprm * bprm,
 134                            unsigned long stack_top,
 135                            int executable_stack);
 136 extern int transfer_args_to_stack(struct linux_binprm *bprm,
 137                                   unsigned long *sp_location);
 138 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
 139 int copy_string_kernel(const char *arg, 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 int kernel_execve(const char *filename,
 144                   const char *const *argv, const char *const *envp);
 145
 146 #endif /* _LINUX_BINFMTS_H */