/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BINFMTS_H
#define _LINUX_BINFMTS_H

#include <linux/sched.h>
#include <linux/unistd.h>
#include <asm/exec.h>
#include <uapi/linux/binfmts.h>

struct filename;
struct coredump_params;

#define CORENAME_MAX_SIZE 128

/*
 * This structure is used to hold the arguments that are used when loading binaries.
 */
struct linux_binprm {
#ifdef CONFIG_MMU
        struct vm_area_struct *vma;
        unsigned long vma_pages;
        unsigned long argmin; /* rlimit marker for copy_strings() */
#else
# define MAX_ARG_PAGES  32
        struct page *page[MAX_ARG_PAGES];
#endif
        struct mm_struct *mm;
        unsigned long p; /* current top of mem */
        unsigned int
                /* Should an execfd be passed to userspace? */
                have_execfd:1,

                /* Use the creds of a script (see binfmt_misc) */
                execfd_creds:1,
                /*
                 * Set by bprm_creds_for_exec hook to indicate a
                 * privilege-gaining exec has happened. Used to set
                 * AT_SECURE auxv for glibc.
                 */
                secureexec:1,
                /*
                 * Set when errors can no longer be returned to the
                 * original userspace.
                 */
                point_of_no_return:1,
                /* Set when "comm" must come from the dentry. */
                comm_from_dentry:1,
                /*
                 * Set by user space to check executability according to the
                 * caller's environment.
                 */
                is_check:1;
        struct file *executable; /* Executable to pass to the interpreter */
        struct file *interpreter;
        struct file *file;
        struct cred *cred;      /* new credentials */
        int unsafe;             /* how unsafe this exec is (mask of LSM_UNSAFE_*) */
        unsigned int per_clear; /* bits to clear in current->personality */
        int argc, envc;
        const char *filename;   /* Name of binary as seen by procps */
        const char *interp;     /* Name of the binary really executed. Most
                                   of the time same as filename, but could be
                                   different for binfmt_{misc,script} */
        const char *fdpath;     /* generated filename for execveat */
        unsigned interp_flags;
        int execfd;             /* File descriptor of the executable */
        unsigned long exec;

        struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */

        char buf[BINPRM_BUF_SIZE];
} __randomize_layout;

#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
#define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)

/* filename of the binary will be inaccessible after exec */
#define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
#define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)

/* preserve argv0 for the interpreter  */
#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)

/*
 * This structure defines the functions that are used to load the binary formats that
 * linux accepts.
 */
struct linux_binfmt {
        struct list_head lh;
        struct module *module;
        int (*load_binary)(struct linux_binprm *);
#ifdef CONFIG_COREDUMP
        int (*core_dump)(struct coredump_params *cprm);
        unsigned long min_coredump;     /* minimal dump size */
#endif
} __randomize_layout;

#if IS_ENABLED(CONFIG_BINFMT_MISC)
struct binfmt_misc {
        struct list_head entries;
        rwlock_t entries_lock;
        bool enabled;
} __randomize_layout;

extern struct binfmt_misc init_binfmt_misc;
#endif

extern void __register_binfmt(struct linux_binfmt *fmt, int insert);

/* Registration of default binfmt handlers */
static inline void register_binfmt(struct linux_binfmt *fmt)
{
        __register_binfmt(fmt, 0);
}
/* Same as above, but adds a new binfmt at the top of the list */
static inline void insert_binfmt(struct linux_binfmt *fmt)
{
        __register_binfmt(fmt, 1);
}

extern void unregister_binfmt(struct linux_binfmt *);

extern int __must_check remove_arg_zero(struct linux_binprm *);
extern int begin_new_exec(struct linux_binprm * bprm);
extern void setup_new_exec(struct linux_binprm * bprm);
extern void finalize_exec(struct linux_binprm *bprm);
extern void would_dump(struct linux_binprm *, struct file *);

extern int suid_dumpable;

/* Stack area protections */
#define EXSTACK_DEFAULT   0     /* Whatever the arch defaults to */
#define EXSTACK_DISABLE_X 1     /* Disable executable stacks */
#define EXSTACK_ENABLE_X  2     /* Enable executable stacks */

extern int setup_arg_pages(struct linux_binprm * bprm,
                           unsigned long stack_top,
                           int executable_stack);
extern int transfer_args_to_stack(struct linux_binprm *bprm,
                                  unsigned long *sp_location);
extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
extern void set_binfmt(struct linux_binfmt *new);
extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);

int kernel_execve(const char *filename,
                  const char *const *argv, const char *const *envp);

#endif /* _LINUX_BINFMTS_H */