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 #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 long argmin; /* rlimit marker for copy_strings() */
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 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
96
97 /* Registration of default binfmt handlers */
register_binfmt(struct linux_binfmt * fmt)98 static inline void register_binfmt(struct linux_binfmt *fmt)
99 {
100 __register_binfmt(fmt, 0);
101 }
102 /* Same as above, but adds a new binfmt at the top of the list */
insert_binfmt(struct linux_binfmt * fmt)103 static inline void insert_binfmt(struct linux_binfmt *fmt)
104 {
105 __register_binfmt(fmt, 1);
106 }
107
108 extern void unregister_binfmt(struct linux_binfmt *);
109
110 extern int __must_check remove_arg_zero(struct linux_binprm *);
111 extern int begin_new_exec(struct linux_binprm * bprm);
112 extern void setup_new_exec(struct linux_binprm * bprm);
113 extern void finalize_exec(struct linux_binprm *bprm);
114 extern void would_dump(struct linux_binprm *, struct file *);
115
116 extern int suid_dumpable;
117
118 /* Stack area protections */
119 #define EXSTACK_DEFAULT 0 /* Whatever the arch defaults to */
120 #define EXSTACK_DISABLE_X 1 /* Disable executable stacks */
121 #define EXSTACK_ENABLE_X 2 /* Enable executable stacks */
122
123 extern int setup_arg_pages(struct linux_binprm * bprm,
124 unsigned long stack_top,
125 int executable_stack);
126 extern int transfer_args_to_stack(struct linux_binprm *bprm,
127 unsigned long *sp_location);
128 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
129 int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
130 extern void set_binfmt(struct linux_binfmt *new);
131 extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
132
133 int kernel_execve(const char *filename,
134 const char *const *argv, const char *const *envp);
135
136 #endif /* _LINUX_BINFMTS_H */
137