xref: /linux-6.15/include/linux/binfmts.h (revision 228cd2db)
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 long argmin; /* rlimit marker for copy_strings() */
29 	unsigned int
30 		/*
31 		 * True after the bprm_set_creds hook has been called once
32 		 * (multiple calls can be made via prepare_binprm() for
33 		 * binfmt_script/misc).
34 		 */
35 		called_set_creds:1,
36 		/*
37 		 * True if most recent call to the commoncaps bprm_set_creds
38 		 * hook (due to multiple prepare_binprm() calls from the
39 		 * binfmt_script/misc handlers) resulted in elevated
40 		 * privileges.
41 		 */
42 		cap_elevated:1,
43 		/*
44 		 * Set by bprm_set_creds hook to indicate a privilege-gaining
45 		 * exec has happened. Used to sanitize execution environment
46 		 * and to set AT_SECURE auxv for glibc.
47 		 */
48 		secureexec:1;
49 #ifdef __alpha__
50 	unsigned int taso:1;
51 #endif
52 	unsigned int recursion_depth; /* only for search_binary_handler() */
53 	struct file * file;
54 	struct cred *cred;	/* new credentials */
55 	int unsafe;		/* how unsafe this exec is (mask of LSM_UNSAFE_*) */
56 	unsigned int per_clear;	/* bits to clear in current->personality */
57 	int argc, envc;
58 	const char * filename;	/* Name of binary as seen by procps */
59 	const char * interp;	/* Name of the binary really executed. Most
60 				   of the time same as filename, but could be
61 				   different for binfmt_{misc,script} */
62 	unsigned interp_flags;
63 	unsigned interp_data;
64 	unsigned long loader, exec;
65 
66 	struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */
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 /* fd of the binary should be passed to the interpreter */
73 #define BINPRM_FLAGS_EXECFD_BIT 1
74 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
75 
76 /* filename of the binary will be inaccessible after exec */
77 #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
78 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_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 };
90 
91 /*
92  * This structure defines the functions that are used to load the binary formats that
93  * linux accepts.
94  */
95 struct linux_binfmt {
96 	struct list_head lh;
97 	struct module *module;
98 	int (*load_binary)(struct linux_binprm *);
99 	int (*load_shlib)(struct file *);
100 	int (*core_dump)(struct coredump_params *cprm);
101 	unsigned long min_coredump;	/* minimal dump size */
102 } __randomize_layout;
103 
104 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
105 
106 /* Registration of default binfmt handlers */
107 static inline void register_binfmt(struct linux_binfmt *fmt)
108 {
109 	__register_binfmt(fmt, 0);
110 }
111 /* Same as above, but adds a new binfmt at the top of the list */
112 static inline void insert_binfmt(struct linux_binfmt *fmt)
113 {
114 	__register_binfmt(fmt, 1);
115 }
116 
117 extern void unregister_binfmt(struct linux_binfmt *);
118 
119 extern int prepare_binprm(struct linux_binprm *);
120 extern int __must_check remove_arg_zero(struct linux_binprm *);
121 extern int search_binary_handler(struct linux_binprm *);
122 extern int flush_old_exec(struct linux_binprm * bprm);
123 extern void setup_new_exec(struct linux_binprm * bprm);
124 extern void finalize_exec(struct linux_binprm *bprm);
125 extern void would_dump(struct linux_binprm *, struct file *);
126 
127 extern int suid_dumpable;
128 
129 /* Stack area protections */
130 #define EXSTACK_DEFAULT   0	/* Whatever the arch defaults to */
131 #define EXSTACK_DISABLE_X 1	/* Disable executable stacks */
132 #define EXSTACK_ENABLE_X  2	/* Enable executable stacks */
133 
134 extern int setup_arg_pages(struct linux_binprm * bprm,
135 			   unsigned long stack_top,
136 			   int executable_stack);
137 extern int transfer_args_to_stack(struct linux_binprm *bprm,
138 				  unsigned long *sp_location);
139 extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
140 extern int copy_strings_kernel(int argc, const char *const *argv,
141 			       struct linux_binprm *bprm);
142 extern void install_exec_creds(struct linux_binprm *bprm);
143 extern void set_binfmt(struct linux_binfmt *new);
144 extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
145 
146 extern int do_execve(struct filename *,
147 		     const char __user * const __user *,
148 		     const char __user * const __user *);
149 extern int do_execveat(int, struct filename *,
150 		       const char __user * const __user *,
151 		       const char __user * const __user *,
152 		       int);
153 int do_execve_file(struct file *file, void *__argv, void *__envp);
154 
155 #endif /* _LINUX_BINFMTS_H */
156