linuxdebug/include/linux/bpfptr.h

89 lines
2.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/* A pointer that can point to either kernel or userspace memory. */
#ifndef _LINUX_BPFPTR_H
#define _LINUX_BPFPTR_H
#include <linux/mm.h>
#include <linux/sockptr.h>
typedef sockptr_t bpfptr_t;
static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
{
return bpfptr.is_kernel;
}
static inline bpfptr_t KERNEL_BPFPTR(void *p)
{
return (bpfptr_t) { .kernel = p, .is_kernel = true };
}
static inline bpfptr_t USER_BPFPTR(void __user *p)
{
return (bpfptr_t) { .user = p };
}
static inline bpfptr_t make_bpfptr(u64 addr, bool is_kernel)
{
if (is_kernel)
return KERNEL_BPFPTR((void*) (uintptr_t) addr);
else
return USER_BPFPTR(u64_to_user_ptr(addr));
}
static inline bool bpfptr_is_null(bpfptr_t bpfptr)
{
if (bpfptr_is_kernel(bpfptr))
return !bpfptr.kernel;
return !bpfptr.user;
}
static inline void bpfptr_add(bpfptr_t *bpfptr, size_t val)
{
if (bpfptr_is_kernel(*bpfptr))
bpfptr->kernel += val;
else
bpfptr->user += val;
}
static inline int copy_from_bpfptr_offset(void *dst, bpfptr_t src,
size_t offset, size_t size)
{
if (!bpfptr_is_kernel(src))
return copy_from_user(dst, src.user + offset, size);
return copy_from_kernel_nofault(dst, src.kernel + offset, size);
}
static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
{
return copy_from_bpfptr_offset(dst, src, 0, size);
}
static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
const void *src, size_t size)
{
return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
}
static inline void *kvmemdup_bpfptr(bpfptr_t src, size_t len)
{
void *p = kvmalloc(len, GFP_USER | __GFP_NOWARN);
if (!p)
return ERR_PTR(-ENOMEM);
if (copy_from_bpfptr(p, src, len)) {
kvfree(p);
return ERR_PTR(-EFAULT);
}
return p;
}
static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
{
if (bpfptr_is_kernel(src))
return strncpy_from_kernel_nofault(dst, src.kernel, count);
return strncpy_from_user(dst, src.user, count);
}
#endif /* _LINUX_BPFPTR_H */