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 /* Set when "comm" must come from the dentry. */ 47 comm_from_dentry:1; 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 /* 81 * This structure defines the functions that are used to load the binary formats that 82 * linux accepts. 83 */ 84 struct linux_binfmt { 85 struct list_head lh; 86 struct module *module; 87 int (*load_binary)(struct linux_binprm *); 88 int (*load_shlib)(struct file *); 89 #ifdef CONFIG_COREDUMP 90 int (*core_dump)(struct coredump_params *cprm); 91 unsigned long min_coredump; /* minimal dump size */ 92 #endif 93 } __randomize_layout; 94 95 #if IS_ENABLED(CONFIG_BINFMT_MISC) 96 struct binfmt_misc { 97 struct list_head entries; 98 rwlock_t entries_lock; 99 bool enabled; 100 } __randomize_layout; 101 102 extern struct binfmt_misc init_binfmt_misc; 103 #endif 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 */ 147