LXR linux/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
  10struct 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 */
  17struct 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 */
  81struct 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};
  90
  91/*
  92 * This structure defines the functions that are used to load the binary formats that
  93 * linux accepts.
  94 */
  95struct linux_binfmt {
  96        struct list_head lh;
  97        struct module *module;
  98        int (*load_binary)(struct linux_binprm *);
  99        int (*load_shlib)(struct file *);
 100        int (*core_dump)(struct coredump_params *cprm);
 101        unsigned long min_coredump;     /* minimal dump size */
 102} __randomize_layout;
 103
 104extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
 105
 106/* Registration of default binfmt handlers */
 107static inline void register_binfmt(struct linux_binfmt *fmt)
 108{
 109        __register_binfmt(fmt, 0);
 110}
 111/* Same as above, but adds a new binfmt at the top of the list */
 112static inline void insert_binfmt(struct linux_binfmt *fmt)
 113{
 114        __register_binfmt(fmt, 1);
 115}
 116
 117extern void unregister_binfmt(struct linux_binfmt *);
 118
 119extern int __must_check remove_arg_zero(struct linux_binprm *);
 120extern int begin_new_exec(struct linux_binprm * bprm);
 121extern void setup_new_exec(struct linux_binprm * bprm);
 122extern void finalize_exec(struct linux_binprm *bprm);
 123extern void would_dump(struct linux_binprm *, struct file *);
 124
 125extern int suid_dumpable;
 126
 127/* Stack area protections */
 128#define EXSTACK_DEFAULT   0     /* Whatever the arch defaults to */
 129#define EXSTACK_DISABLE_X 1     /* Disable executable stacks */
 130#define EXSTACK_ENABLE_X  2     /* Enable executable stacks */
 131
 132extern int setup_arg_pages(struct linux_binprm * bprm,
 133                           unsigned long stack_top,
 134                           int executable_stack);
 135extern int transfer_args_to_stack(struct linux_binprm *bprm,
 136                                  unsigned long *sp_location);
 137extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
 138int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
 139extern void set_binfmt(struct linux_binfmt *new);
 140extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
 141
 142int kernel_execve(const char *filename,
 143                  const char *const *argv, const char *const *envp);
 144
 145#endif /* _LINUX_BINFMTS_H */
 146