#include <linux/uaccess.h> #include <linux/export.h> #include <linux/uio.h> /* * Copy iovec to kernel. Returns -EFAULT on error. * * Note: this modifies the original iovec. */ int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len) { while (len > 0) { if (iov->iov_len) { int copy = min_t(unsigned int, len, iov->iov_len); if (copy_from_user(kdata, iov->iov_base, copy)) return -EFAULT; len -= copy; kdata += copy; iov->iov_base += copy; iov->iov_len -= copy; } iov++; } return 0; } EXPORT_SYMBOL(memcpy_fromiovec); /* * Copy kernel to iovec. Returns -EFAULT on error. * * Note: this modifies the original iovec. */ int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len) { while (len > 0) { if (iov->iov_len) { int copy = min_t(unsigned int, iov->iov_len, len); if (copy_to_user(iov->iov_base, kdata, copy)) return -EFAULT; kdata += copy; len -= copy; iov->iov_len -= copy; iov->iov_base += copy; } iov++; } return 0; } EXPORT_SYMBOL(memcpy_toiovec); /* * Copy kernel to iovec. Returns -EFAULT on error. */ int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata, int offset, int len) { int copy; for (; len > 0; ++iov) { /* Skip over the finished iovecs */ if (unlikely(offset >= iov->iov_len)) { offset -= iov->iov_len; continue; } copy = min_t(unsigned int, iov->iov_len - offset, len); if (copy_to_user(iov->iov_base + offset, kdata, copy)) return -EFAULT; offset = 0; kdata += copy; len -= copy; } return 0; } EXPORT_SYMBOL(memcpy_toiovecend); /* * Copy iovec to kernel. Returns -EFAULT on error. */ int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, int offset, int len) { /* No data? Done! */ if (len == 0) return 0; /* Skip over the finished iovecs */ while (offset >= iov->iov_len) { offset -= iov->iov_len; iov++; } while (len > 0) { u8 __user *base = iov->iov_base + offset; int copy = min_t(unsigned int, len, iov->iov_len - offset); offset = 0; if (copy_from_user(kdata, base, copy)) return -EFAULT; len -= copy; kdata += copy; iov++; } return 0; } EXPORT_SYMBOL(memcpy_fromiovecend);