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
12 #define CORENAME_MAX_SIZE 128
13
14 /*
15 * This structure is used to hold the arguments that are used when loading binaries.
16 */
17 struct linux_binprm {
18 #ifdef CONFIG_MMU
19 struct vm_area_struct *vma;
20 unsigned long vma_pages;
21 #else
22 # define MAX_ARG_PAGES 32
23 struct page *page[MAX_ARG_PAGES];
24 #endif
25 struct mm_struct *mm;
26 unsigned long p; /* current top of mem */
27 unsigned long argmin; /* rlimit marker for copy_strings() */
28 unsigned int
29 /* Should an execfd be passed to userspace? */
30 have_execfd:1,
31
32 /* Use the creds of a script (see binfmt_misc) */
33 execfd_creds:1,
34 /*
35 * Set by bprm_creds_for_exec hook to indicate a
36 * privilege-gaining exec has happened. Used to set
37 * AT_SECURE auxv for glibc.
38 */
39 secureexec:1,
40 /*
41 * Set when errors can no longer be returned to the
42 * original userspace.
43 */
44 point_of_no_return:1;
45 #ifdef __alpha__
46 unsigned int taso:1;
47 #endif
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 /* Function parameter for binfmt->coredump */
81 struct coredump_params {
82 const kernel_siginfo_t *siginfo;
83 struct pt_regs *regs;
84 struct file *file;
85 unsigned long limit;
86 unsigned long mm_flags;
87 loff_t written;
88 loff_t pos;
89 loff_t to_skip;
90 };
91
92 /*
93 * This structure defines the functions that are used to load the binary formats that
94 * linux accepts.
95 */
96 struct linux_binfmt {
97 struct list_head lh;
98 struct module *module;
99 int (*load_binary)(struct linux_binprm *);
100 int (*load_shlib)(struct file *);
101 int (*core_dump)(struct coredump_params *cprm);
102 unsigned long min_coredump; /* minimal dump size */
103 } __randomize_layout;
104
105 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
106
107 /* Registration of default binfmt handlers */
register_binfmt(struct linux_binfmt * fmt)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 */
insert_binfmt(struct linux_binfmt * fmt)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
