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UFFDIO_WRITEPROTECT(2const) UFFDIO_WRITEPROTECT(2const)
UFFDIO_WRITEPROTECT - write-protect or write-unprotect a userfaultfd-registered memory range
Standard C library (libc, -lc)
#include <linux/userfaultfd.h> /* Definition of UFFD* constants */ #include <sys/ioctl.h> int ioctl(int fd, UFFDIO_WRITEPROTECT, ...); #include <linux/userfaultfd.h> struct uffdio_writeprotect { struct uffdio_range range; /* Range to change write permission*/ __u64 mode; /* Mode to change write permission */ };
Write-protect or write-unprotect a userfaultfd-registered memory range registered with mode UFFDIO_REGISTER_MODE_WP. There are two mode bits that are supported in this structure: UFFDIO_WRITEPROTECT_MODE_WP When this mode bit is set, the ioctl will be a write- protect operation upon the memory range specified by range. Otherwise it will be a write-unprotect operation upon the specified range, which can be used to resolve a userfaultfd write-protect page fault. UFFDIO_WRITEPROTECT_MODE_DONTWAKE When this mode bit is set, do not wake up any thread that waits for page-fault resolution after the operation. This can be specified only if UFFDIO_WRITEPROTECT_MODE_WP is not specified.
On success, 0 is returned. On error, -1 is returned and errno is set to indicate the error.
EINVAL The start or the len field of the ufdio_range structure was not a multiple of the system page size; or len was zero; or the specified range was otherwise invalid. EAGAIN The process was interrupted; retry this call. ENOENT The range specified in range is not valid. For example, the virtual address does not exist, or not registered with userfaultfd write-protect mode. EFAULT Encountered a generic fault during processing.
Linux.
Linux 5.7.
See userfaultfd(2).
ioctl(2), ioctl_userfaultfd(2), userfaultfd(2) Documentation/admin-guide/mm/userfaultfd.rst in the Linux kernel source tree
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Linux man-pages 6.9.1 2024-06-17 UFFDIO_WRITEPROTECT(2const)
Pages that refer to this page: ioctl_userfaultfd(2)