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 struct coredump_params; 12 13 #define CORENAME_MAX_SIZE 128 14 15 /* 16 * This structure is used to hold the arguments that are used when loading binaries. 17 */ 18 struct linux_binprm { 19 #ifdef CONFIG_MMU 20 struct vm_area_struct *vma; 21 unsigned long vma_pages; 22 unsigned long argmin; /* rlimit marker for copy_strings() */ 23 #else 24 # define MAX_ARG_PAGES 32 25 struct page *page[MAX_ARG_PAGES]; 26 #endif 27 struct mm_struct *mm; 28 unsigned long p; /* current top of mem */ 29 unsigned int 30 /* Should an execfd be passed to userspace? */ 31 have_execfd:1, 32 33 /* Use the creds of a script (see binfmt_misc) */ 34 execfd_creds:1, 35 /* 36 * Set by bprm_creds_for_exec hook to indicate a 37 * privilege-gaining exec has happened. Used to set 38 * AT_SECURE auxv for glibc. 39 */ 40 secureexec:1, 41 /* 42 * Set when errors can no longer be returned to the 43 * original userspace. 44 */ 45 point_of_no_return:1, 46 /* 47 * Set by user space to check executability according to the 48 * caller's environment. 49 */ 50 is_check:1; 51 struct file *executable; /* Executable to pass to the interpreter */ 52 struct file *interpreter; 53 struct file *file; 54 struct cred *cred; /* new credentials */ 55 int unsafe; /* how unsafe this exec is (mask of LSM_UNSAFE_*) */ 56 unsigned int per_clear; /* bits to clear in current->personality */ 57 int argc, envc; 58 const char *filename; /* Name of binary as seen by procps */ 59 const char *interp; /* Name of the binary really executed. Most 60 of the time same as filename, but could be 61 different for binfmt_{misc,script} */ 62 const char *fdpath; /* generated filename for execveat */ 63 unsigned interp_flags; 64 int execfd; /* File descriptor of the executable */ 65 unsigned long loader, exec; 66 67 struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */ 68 69 char buf[BINPRM_BUF_SIZE]; 70 } __randomize_layout; 71 72 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0 73 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT) 74 75 /* filename of the binary will be inaccessible after exec */ 76 #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2 77 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT) 78 79 /* preserve argv0 for the interpreter */ 80 #define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3 81 #define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT) 82 83 /* 84 * This structure defines the functions that are used to load the binary formats that 85 * linux accepts. 86 */ 87 struct linux_binfmt { 88 struct list_head lh; 89 struct module *module; 90 int (*load_binary)(struct linux_binprm *); 91 int (*load_shlib)(struct file *); 92 #ifdef CONFIG_COREDUMP 93 int (*core_dump)(struct coredump_params *cprm); 94 unsigned long min_coredump; /* minimal dump size */ 95 #endif 96 } __randomize_layout; 97 98 #if IS_ENABLED(CONFIG_BINFMT_MISC) 99 struct binfmt_misc { 100 struct list_head entries; 101 rwlock_t entries_lock; 102 bool enabled; 103 } __randomize_layout; 104 105 extern struct binfmt_misc init_binfmt_misc; 106 #endif 107 108 extern void __register_binfmt(struct linux_binfmt *fmt, int insert); 109 110 /* Registration of default binfmt handlers */ 111 static inline void register_binfmt(struct linux_binfmt *fmt) 112 { 113 __register_binfmt(fmt, 0); 114 } 115 /* Same as above, but adds a new binfmt at the top of the list */ 116 static inline void insert_binfmt(struct linux_binfmt *fmt) 117 { 118 __register_binfmt(fmt, 1); 119 } 120 121 extern void unregister_binfmt(struct linux_binfmt *); 122 123 extern int __must_check remove_arg_zero(struct linux_binprm *); 124 extern int begin_new_exec(struct linux_binprm * bprm); 125 extern void setup_new_exec(struct linux_binprm * bprm); 126 extern void finalize_exec(struct linux_binprm *bprm); 127 extern void would_dump(struct linux_binprm *, struct file *); 128 129 extern int suid_dumpable; 130 131 /* Stack area protections */ 132 #define EXSTACK_DEFAULT 0 /* Whatever the arch defaults to */ 133 #define EXSTACK_DISABLE_X 1 /* Disable executable stacks */ 134 #define EXSTACK_ENABLE_X 2 /* Enable executable stacks */ 135 136 extern int setup_arg_pages(struct linux_binprm * bprm, 137 unsigned long stack_top, 138 int executable_stack); 139 extern int transfer_args_to_stack(struct linux_binprm *bprm, 140 unsigned long *sp_location); 141 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm); 142 int copy_string_kernel(const char *arg, struct linux_binprm *bprm); 143 extern void set_binfmt(struct linux_binfmt *new); 144 extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t); 145 146 int kernel_execve(const char *filename, 147 const char *const *argv, const char *const *envp); 148 149 #endif /* _LINUX_BINFMTS_H */ 150