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;
11struct 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 */
18struct 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 struct file *executable; /* Executable to pass to the interpreter */
47 struct file *interpreter;
48 struct file *file;
49 struct cred *cred; /* new credentials */
50 int unsafe; /* how unsafe this exec is (mask of LSM_UNSAFE_*) */
51 unsigned int per_clear; /* bits to clear in current->personality */
52 int argc, envc;
53 const char *filename; /* Name of binary as seen by procps */
54 const char *interp; /* Name of the binary really executed. Most
55 of the time same as filename, but could be
56 different for binfmt_{misc,script} */
57 const char *fdpath; /* generated filename for execveat */
58 unsigned interp_flags;
59 int execfd; /* File descriptor of the executable */
60 unsigned long loader, exec;
61
62 struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */
63
64 char buf[BINPRM_BUF_SIZE];
65} __randomize_layout;
66
67#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
68#define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
69
70/* filename of the binary will be inaccessible after exec */
71#define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
72#define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
73
74/* preserve argv0 for the interpreter */
75#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
76#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
77
78/*
79 * This structure defines the functions that are used to load the binary formats that
80 * linux accepts.
81 */
82struct linux_binfmt {
83 struct list_head lh;
84 struct module *module;
85 int (*load_binary)(struct linux_binprm *);
86 int (*load_shlib)(struct file *);
87#ifdef CONFIG_COREDUMP
88 int (*core_dump)(struct coredump_params *cprm);
89 unsigned long min_coredump; /* minimal dump size */
90#endif
91} __randomize_layout;
92
93#if IS_ENABLED(CONFIG_BINFMT_MISC)
94struct binfmt_misc {
95 struct list_head entries;
96 rwlock_t entries_lock;
97 bool enabled;
98} __randomize_layout;
99
100extern struct binfmt_misc init_binfmt_misc;
101#endif
102
103extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
104
105/* Registration of default binfmt handlers */
106static inline void register_binfmt(struct linux_binfmt *fmt)
107{
108 __register_binfmt(fmt, insert: 0);
109}
110/* Same as above, but adds a new binfmt at the top of the list */
111static inline void insert_binfmt(struct linux_binfmt *fmt)
112{
113 __register_binfmt(fmt, insert: 1);
114}
115
116extern void unregister_binfmt(struct linux_binfmt *);
117
118extern int __must_check remove_arg_zero(struct linux_binprm *);
119extern int begin_new_exec(struct linux_binprm * bprm);
120extern void setup_new_exec(struct linux_binprm * bprm);
121extern void finalize_exec(struct linux_binprm *bprm);
122extern void would_dump(struct linux_binprm *, struct file *);
123
124extern int suid_dumpable;
125
126/* Stack area protections */
127#define EXSTACK_DEFAULT 0 /* Whatever the arch defaults to */
128#define EXSTACK_DISABLE_X 1 /* Disable executable stacks */
129#define EXSTACK_ENABLE_X 2 /* Enable executable stacks */
130
131extern int setup_arg_pages(struct linux_binprm * bprm,
132 unsigned long stack_top,
133 int executable_stack);
134extern int transfer_args_to_stack(struct linux_binprm *bprm,
135 unsigned long *sp_location);
136extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
137int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
138extern void set_binfmt(struct linux_binfmt *new);
139extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
140
141int kernel_execve(const char *filename,
142 const char *const *argv, const char *const *envp);
143
144#endif /* _LINUX_BINFMTS_H */
145

source code of linux/include/linux/binfmts.h