xref: /linux-6.15/include/linux/binfmts.h (revision e00a844a)
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 	char buf[BINPRM_BUF_SIZE];
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 int
29 		/*
30 		 * True after the bprm_set_creds hook has been called once
31 		 * (multiple calls can be made via prepare_binprm() for
32 		 * binfmt_script/misc).
33 		 */
34 		called_set_creds:1,
35 		/*
36 		 * True if most recent call to the commoncaps bprm_set_creds
37 		 * hook (due to multiple prepare_binprm() calls from the
38 		 * binfmt_script/misc handlers) resulted in elevated
39 		 * privileges.
40 		 */
41 		cap_elevated:1,
42 		/*
43 		 * Set by bprm_set_creds hook to indicate a privilege-gaining
44 		 * exec has happened. Used to sanitize execution environment
45 		 * and to set AT_SECURE auxv for glibc.
46 		 */
47 		secureexec:1;
48 #ifdef __alpha__
49 	unsigned int taso:1;
50 #endif
51 	unsigned int recursion_depth; /* only for search_binary_handler() */
52 	struct file * file;
53 	struct cred *cred;	/* new credentials */
54 	int unsafe;		/* how unsafe this exec is (mask of LSM_UNSAFE_*) */
55 	unsigned int per_clear;	/* bits to clear in current->personality */
56 	int argc, envc;
57 	const char * filename;	/* Name of binary as seen by procps */
58 	const char * interp;	/* Name of the binary really executed. Most
59 				   of the time same as filename, but could be
60 				   different for binfmt_{misc,script} */
61 	unsigned interp_flags;
62 	unsigned interp_data;
63 	unsigned long loader, exec;
64 } __randomize_layout;
65 
66 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
67 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
68 
69 /* fd of the binary should be passed to the interpreter */
70 #define BINPRM_FLAGS_EXECFD_BIT 1
71 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
72 
73 /* filename of the binary will be inaccessible after exec */
74 #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
75 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
76 
77 /* Function parameter for binfmt->coredump */
78 struct coredump_params {
79 	const siginfo_t *siginfo;
80 	struct pt_regs *regs;
81 	struct file *file;
82 	unsigned long limit;
83 	unsigned long mm_flags;
84 	loff_t written;
85 	loff_t pos;
86 };
87 
88 /*
89  * This structure defines the functions that are used to load the binary formats that
90  * linux accepts.
91  */
92 struct linux_binfmt {
93 	struct list_head lh;
94 	struct module *module;
95 	int (*load_binary)(struct linux_binprm *);
96 	int (*load_shlib)(struct file *);
97 	int (*core_dump)(struct coredump_params *cprm);
98 	unsigned long min_coredump;	/* minimal dump size */
99 } __randomize_layout;
100 
101 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
102 
103 /* Registration of default binfmt handlers */
104 static inline void register_binfmt(struct linux_binfmt *fmt)
105 {
106 	__register_binfmt(fmt, 0);
107 }
108 /* Same as above, but adds a new binfmt at the top of the list */
109 static inline void insert_binfmt(struct linux_binfmt *fmt)
110 {
111 	__register_binfmt(fmt, 1);
112 }
113 
114 extern void unregister_binfmt(struct linux_binfmt *);
115 
116 extern int prepare_binprm(struct linux_binprm *);
117 extern int __must_check remove_arg_zero(struct linux_binprm *);
118 extern int search_binary_handler(struct linux_binprm *);
119 extern int flush_old_exec(struct linux_binprm * bprm);
120 extern void setup_new_exec(struct linux_binprm * bprm);
121 extern void would_dump(struct linux_binprm *, struct file *);
122 
123 extern int suid_dumpable;
124 
125 /* Stack area protections */
126 #define EXSTACK_DEFAULT   0	/* Whatever the arch defaults to */
127 #define EXSTACK_DISABLE_X 1	/* Disable executable stacks */
128 #define EXSTACK_ENABLE_X  2	/* Enable executable stacks */
129 
130 extern int setup_arg_pages(struct linux_binprm * bprm,
131 			   unsigned long stack_top,
132 			   int executable_stack);
133 extern int transfer_args_to_stack(struct linux_binprm *bprm,
134 				  unsigned long *sp_location);
135 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
136 extern int copy_strings_kernel(int argc, const char *const *argv,
137 			       struct linux_binprm *bprm);
138 extern int prepare_bprm_creds(struct linux_binprm *bprm);
139 extern void install_exec_creds(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 extern int do_execve(struct filename *,
144 		     const char __user * const __user *,
145 		     const char __user * const __user *);
146 extern int do_execveat(int, struct filename *,
147 		       const char __user * const __user *,
148 		       const char __user * const __user *,
149 		       int);
150 
151 #endif /* _LINUX_BINFMTS_H */
152