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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 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 /*
49 * Set by user space to check executability according to the
50 * caller's environment.
51 */
52 is_check:1;
53 struct file *executable; /* Executable to pass to the interpreter */
54 struct file *interpreter;
55 struct file *file;
56 struct cred *cred; /* new credentials */
57 int unsafe; /* how unsafe this exec is (mask of LSM_UNSAFE_*) */
58 unsigned int per_clear; /* bits to clear in current->personality */
59 int argc, envc;
60 const char *filename; /* Name of binary as seen by procps */
61 const char *interp; /* Name of the binary really executed. Most
62 of the time same as filename, but could be
63 different for binfmt_{misc,script} */
64 const char *fdpath; /* generated filename for execveat */
65 unsigned interp_flags;
66 int execfd; /* File descriptor of the executable */
67 unsigned long exec;
68
69 struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */
70
71 char buf[BINPRM_BUF_SIZE];
72} __randomize_layout;
73
74#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
75#define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
76
77/* filename of the binary will be inaccessible after exec */
78#define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
79#define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
80
81/* preserve argv0 for the interpreter */
82#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
83#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
84
85/*
86 * This structure defines the functions that are used to load the binary formats that
87 * linux accepts.
88 */
89struct linux_binfmt {
90 struct list_head lh;
91 struct module *module;
92 int (*load_binary)(struct linux_binprm *);
93#ifdef CONFIG_COREDUMP
94 int (*core_dump)(struct coredump_params *cprm);
95 unsigned long min_coredump; /* minimal dump size */
96#endif
97} __randomize_layout;
98
99#if IS_ENABLED(CONFIG_BINFMT_MISC)
100struct binfmt_misc {
101 struct list_head entries;
102 rwlock_t entries_lock;
103 bool enabled;
104} __randomize_layout;
105
106extern struct binfmt_misc init_binfmt_misc;
107#endif
108
109extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
110
111/* Registration of default binfmt handlers */
112static inline void register_binfmt(struct linux_binfmt *fmt)
113{
114 __register_binfmt(fmt, insert: 0);
115}
116/* Same as above, but adds a new binfmt at the top of the list */
117static inline void insert_binfmt(struct linux_binfmt *fmt)
118{
119 __register_binfmt(fmt, insert: 1);
120}
121
122extern void unregister_binfmt(struct linux_binfmt *);
123
124extern int __must_check remove_arg_zero(struct linux_binprm *);
125extern int begin_new_exec(struct linux_binprm * bprm);
126extern void setup_new_exec(struct linux_binprm * bprm);
127extern void finalize_exec(struct linux_binprm *bprm);
128extern void would_dump(struct linux_binprm *, struct file *);
129
130extern int suid_dumpable;
131
132/* Stack area protections */
133#define EXSTACK_DEFAULT 0 /* Whatever the arch defaults to */
134#define EXSTACK_DISABLE_X 1 /* Disable executable stacks */
135#define EXSTACK_ENABLE_X 2 /* Enable executable stacks */
136
137extern int setup_arg_pages(struct linux_binprm * bprm,
138 unsigned long stack_top,
139 int executable_stack);
140extern int transfer_args_to_stack(struct linux_binprm *bprm,
141 unsigned long *sp_location);
142extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
143int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
144extern void set_binfmt(struct linux_binfmt *new);
145extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
146
147int kernel_execve(const char *filename,
148 const char *const *argv, const char *const *envp);
149
150#endif /* _LINUX_BINFMTS_H */
151

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