xref: /linux-6.15/include/linux/binfmts.h (revision c6d3aaa4)
1 #ifndef _LINUX_BINFMTS_H
2 #define _LINUX_BINFMTS_H
3 
4 #include <linux/capability.h>
5 
6 struct pt_regs;
7 
8 /*
9  * These are the maximum length and maximum number of strings passed to the
10  * execve() system call.  MAX_ARG_STRLEN is essentially random but serves to
11  * prevent the kernel from being unduly impacted by misaddressed pointers.
12  * MAX_ARG_STRINGS is chosen to fit in a signed 32-bit integer.
13  */
14 #define MAX_ARG_STRLEN (PAGE_SIZE * 32)
15 #define MAX_ARG_STRINGS 0x7FFFFFFF
16 
17 /* sizeof(linux_binprm->buf) */
18 #define BINPRM_BUF_SIZE 128
19 
20 #ifdef __KERNEL__
21 #include <linux/list.h>
22 
23 #define CORENAME_MAX_SIZE 128
24 
25 /*
26  * This structure is used to hold the arguments that are used when loading binaries.
27  */
28 struct linux_binprm{
29 	char buf[BINPRM_BUF_SIZE];
30 #ifdef CONFIG_MMU
31 	struct vm_area_struct *vma;
32 #else
33 # define MAX_ARG_PAGES	32
34 	struct page *page[MAX_ARG_PAGES];
35 #endif
36 	struct mm_struct *mm;
37 	unsigned long p; /* current top of mem */
38 	unsigned int
39 		cred_prepared:1,/* true if creds already prepared (multiple
40 				 * preps happen for interpreters) */
41 		cap_effective:1;/* true if has elevated effective capabilities,
42 				 * false if not; except for init which inherits
43 				 * its parent's caps anyway */
44 #ifdef __alpha__
45 	unsigned int taso:1;
46 #endif
47 	unsigned int recursion_depth;
48 	struct file * file;
49 	struct cred *cred;	/* new credentials */
50 	int unsafe;		/* how unsafe this exec is (mask of LSM_UNSAFE_*) */
51 	unsigned int per_clear;	/* bits to clear in current->personality */
52 	int argc, envc;
53 	char * filename;	/* Name of binary as seen by procps */
54 	char * interp;		/* Name of the binary really executed. Most
55 				   of the time same as filename, but could be
56 				   different for binfmt_{misc,script} */
57 	unsigned interp_flags;
58 	unsigned interp_data;
59 	unsigned long loader, exec;
60 };
61 
62 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
63 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
64 
65 /* fd of the binary should be passed to the interpreter */
66 #define BINPRM_FLAGS_EXECFD_BIT 1
67 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
68 
69 #define BINPRM_MAX_RECURSION 4
70 
71 /*
72  * This structure defines the functions that are used to load the binary formats that
73  * linux accepts.
74  */
75 struct linux_binfmt {
76 	struct list_head lh;
77 	struct module *module;
78 	int (*load_binary)(struct linux_binprm *, struct  pt_regs * regs);
79 	int (*load_shlib)(struct file *);
80 	int (*core_dump)(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
81 	unsigned long min_coredump;	/* minimal dump size */
82 	int hasvdso;
83 };
84 
85 extern int __register_binfmt(struct linux_binfmt *fmt, int insert);
86 
87 /* Registration of default binfmt handlers */
88 static inline int register_binfmt(struct linux_binfmt *fmt)
89 {
90 	return __register_binfmt(fmt, 0);
91 }
92 /* Same as above, but adds a new binfmt at the top of the list */
93 static inline int insert_binfmt(struct linux_binfmt *fmt)
94 {
95 	return __register_binfmt(fmt, 1);
96 }
97 
98 extern void unregister_binfmt(struct linux_binfmt *);
99 
100 extern int prepare_binprm(struct linux_binprm *);
101 extern int __must_check remove_arg_zero(struct linux_binprm *);
102 extern int search_binary_handler(struct linux_binprm *,struct pt_regs *);
103 extern int flush_old_exec(struct linux_binprm * bprm);
104 
105 extern int suid_dumpable;
106 #define SUID_DUMP_DISABLE	0	/* No setuid dumping */
107 #define SUID_DUMP_USER		1	/* Dump as user of process */
108 #define SUID_DUMP_ROOT		2	/* Dump as root */
109 
110 /* Stack area protections */
111 #define EXSTACK_DEFAULT   0	/* Whatever the arch defaults to */
112 #define EXSTACK_DISABLE_X 1	/* Disable executable stacks */
113 #define EXSTACK_ENABLE_X  2	/* Enable executable stacks */
114 
115 extern int setup_arg_pages(struct linux_binprm * bprm,
116 			   unsigned long stack_top,
117 			   int executable_stack);
118 extern int bprm_mm_init(struct linux_binprm *bprm);
119 extern int copy_strings_kernel(int argc,char ** argv,struct linux_binprm *bprm);
120 extern int prepare_bprm_creds(struct linux_binprm *bprm);
121 extern void install_exec_creds(struct linux_binprm *bprm);
122 extern void do_coredump(long signr, int exit_code, struct pt_regs *regs);
123 extern void set_binfmt(struct linux_binfmt *new);
124 extern void free_bprm(struct linux_binprm *);
125 
126 #endif /* __KERNEL__ */
127 #endif /* _LINUX_BINFMTS_H */
128