xref: /linux-6.15/include/linux/binfmts.h (revision bb7e5ce7)
1 #ifndef _LINUX_BINFMTS_H
2 #define _LINUX_BINFMTS_H
3 
4 #include <linux/sched.h>
5 #include <linux/unistd.h>
6 #include <asm/exec.h>
7 #include <uapi/linux/binfmts.h>
8 
9 struct filename;
10 
11 #define CORENAME_MAX_SIZE 128
12 
13 /*
14  * This structure is used to hold the arguments that are used when loading binaries.
15  */
16 struct linux_binprm {
17 	char buf[BINPRM_BUF_SIZE];
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 int
28 		/*
29 		 * True after the bprm_set_creds hook has been called once
30 		 * (multiple calls can be made via prepare_binprm() for
31 		 * binfmt_script/misc).
32 		 */
33 		called_set_creds:1,
34 		/*
35 		 * True if most recent call to the commoncaps bprm_set_creds
36 		 * hook (due to multiple prepare_binprm() calls from the
37 		 * binfmt_script/misc handlers) resulted in elevated
38 		 * privileges.
39 		 */
40 		cap_elevated:1,
41 		/*
42 		 * Set by bprm_set_creds hook to indicate a privilege-gaining
43 		 * exec has happened. Used to sanitize execution environment
44 		 * and to set AT_SECURE auxv for glibc.
45 		 */
46 		secureexec:1;
47 #ifdef __alpha__
48 	unsigned int taso:1;
49 #endif
50 	unsigned int recursion_depth; /* only for search_binary_handler() */
51 	struct file * file;
52 	struct cred *cred;	/* new credentials */
53 	int unsafe;		/* how unsafe this exec is (mask of LSM_UNSAFE_*) */
54 	unsigned int per_clear;	/* bits to clear in current->personality */
55 	int argc, envc;
56 	const char * filename;	/* Name of binary as seen by procps */
57 	const char * interp;	/* Name of the binary really executed. Most
58 				   of the time same as filename, but could be
59 				   different for binfmt_{misc,script} */
60 	unsigned interp_flags;
61 	unsigned interp_data;
62 	unsigned long loader, exec;
63 } __randomize_layout;
64 
65 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
66 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
67 
68 /* fd of the binary should be passed to the interpreter */
69 #define BINPRM_FLAGS_EXECFD_BIT 1
70 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_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 /* Function parameter for binfmt->coredump */
77 struct coredump_params {
78 	const siginfo_t *siginfo;
79 	struct pt_regs *regs;
80 	struct file *file;
81 	unsigned long limit;
82 	unsigned long mm_flags;
83 	loff_t written;
84 	loff_t pos;
85 };
86 
87 /*
88  * This structure defines the functions that are used to load the binary formats that
89  * linux accepts.
90  */
91 struct linux_binfmt {
92 	struct list_head lh;
93 	struct module *module;
94 	int (*load_binary)(struct linux_binprm *);
95 	int (*load_shlib)(struct file *);
96 	int (*core_dump)(struct coredump_params *cprm);
97 	unsigned long min_coredump;	/* minimal dump size */
98 } __randomize_layout;
99 
100 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
101 
102 /* Registration of default binfmt handlers */
103 static inline void register_binfmt(struct linux_binfmt *fmt)
104 {
105 	__register_binfmt(fmt, 0);
106 }
107 /* Same as above, but adds a new binfmt at the top of the list */
108 static inline void insert_binfmt(struct linux_binfmt *fmt)
109 {
110 	__register_binfmt(fmt, 1);
111 }
112 
113 extern void unregister_binfmt(struct linux_binfmt *);
114 
115 extern int prepare_binprm(struct linux_binprm *);
116 extern int __must_check remove_arg_zero(struct linux_binprm *);
117 extern int search_binary_handler(struct linux_binprm *);
118 extern int flush_old_exec(struct linux_binprm * bprm);
119 extern void setup_new_exec(struct linux_binprm * bprm);
120 extern void would_dump(struct linux_binprm *, struct file *);
121 
122 extern int suid_dumpable;
123 
124 /* Stack area protections */
125 #define EXSTACK_DEFAULT   0	/* Whatever the arch defaults to */
126 #define EXSTACK_DISABLE_X 1	/* Disable executable stacks */
127 #define EXSTACK_ENABLE_X  2	/* Enable executable stacks */
128 
129 extern int setup_arg_pages(struct linux_binprm * bprm,
130 			   unsigned long stack_top,
131 			   int executable_stack);
132 extern int transfer_args_to_stack(struct linux_binprm *bprm,
133 				  unsigned long *sp_location);
134 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
135 extern int copy_strings_kernel(int argc, const char *const *argv,
136 			       struct linux_binprm *bprm);
137 extern int prepare_bprm_creds(struct linux_binprm *bprm);
138 extern void install_exec_creds(struct linux_binprm *bprm);
139 extern void set_binfmt(struct linux_binfmt *new);
140 extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
141 
142 extern int do_execve(struct filename *,
143 		     const char __user * const __user *,
144 		     const char __user * const __user *);
145 extern int do_execveat(int, struct filename *,
146 		       const char __user * const __user *,
147 		       const char __user * const __user *,
148 		       int);
149 
150 #endif /* _LINUX_BINFMTS_H */
151