Debug, Updated gitignore

.gitignore

@@ -1 +1,2 @@
 test/**
+.gdb_history

src/aarch64-linux-flush-dcache/.gitignore

@@ -0,0 +1,171 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# NOTE! Don't add files that are generated in specific
+# subdirectories here. Add them in the ".gitignore" file
+# in that subdirectory instead.
+#
+# NOTE! Please use 'git ls-files -i -c --exclude-per-directory=.gitignore'
+# command after changing this file, to see if there are
+# any tracked files which get ignored after the change.
+#
+# Normal rules (sorted alphabetically)
+#
+.*
+*.a
+*.asn1.[ch]
+*.bin
+*.bz2
+*.c.[012]*.*
+*.dt.yaml
+*.dtb
+*.dtbo
+*.dtb.S
+*.dtbo.S
+*.dwo
+*.elf
+*.gcno
+*.gz
+*.i
+*.ko
+*.lex.c
+*.ll
+*.lst
+*.lz4
+*.lzma
+*.lzo
+*.mod
+*.mod.c
+*.o
+*.o.*
+*.patch
+*.rmeta
+*.rpm
+*.rsi
+*.s
+*.so
+*.so.dbg
+*.su
+*.symtypes
+*.symversions
+*.tab.[ch]
+*.tar
+*.xz
+*.zst
+Module.symvers
+modules.order
+
+#
+# Top-level generic files
+#
+/linux
+/modules-only.symvers
+/vmlinux
+/vmlinux.32
+/vmlinux.map
+/vmlinux.symvers
+/vmlinux-gdb.py
+/vmlinuz
+/System.map
+/Module.markers
+/modules.builtin
+/modules.builtin.modinfo
+/modules.nsdeps
+
+#
+# RPM spec file (make rpm-pkg)
+#
+/rpmbuild/
+
+#
+# Debian directory (make deb-pkg)
+#
+/debian/
+
+#
+# Snap directory (make snap-pkg)
+#
+/snap/
+
+#
+# tar directory (make tar*-pkg)
+#
+/tar-install/
+
+#
+# We don't want to ignore the following even if they are dot-files
+#
+!.clang-format
+!.cocciconfig
+!.get_maintainer.ignore
+!.gitattributes
+!.gitignore
+!.kunitconfig
+!.mailmap
+!.rustfmt.toml
+
+#
+# Generated include files
+#
+/include/config/
+/include/generated/
+/arch/*/include/generated/
+
+# stgit generated dirs
+patches-*
+
+# quilt's files
+patches
+series
+
+# ctags files
+tags
+TAGS
+
+# cscope files
+cscope.*
+ncscope.*
+
+# gnu global files
+GPATH
+GRTAGS
+GSYMS
+GTAGS
+
+# id-utils files
+ID
+
+*.orig
+*~
+\#*#
+
+#
+# Leavings from module signing
+#
+extra_certificates
+signing_key.pem
+signing_key.priv
+signing_key.x509
+x509.genkey
+
+# Kconfig presets
+/all.config
+/alldef.config
+/allmod.config
+/allno.config
+/allrandom.config
+/allyes.config
+
+# Kconfig savedefconfig output
+/defconfig
+
+# Kdevelop4
+*.kdev4
+
+# Clang's compilation database file
+/compile_commands.json
+
+# Documentation toolchain
+sphinx_*/
+
+# Rust analyzer configuration
+/rust-project.json

src/aarch64-linux-flush-dcache/my_shmem.c

@@ -77,8 +77,10 @@ static vm_fault_t my_shmem_vmops_fault(struct vm_fault *vmf)
 	mutex_lock(&my_shmem_pages_mtx);
 	if (nr_pages_from_vm_start < my_shmem_page_count) {
 		/* Offset in range, return existing page */
-		pr_info("[%s] Found remappable page nr: %lu, offset: %lu.\n",
+		pr_info("[%s] Found remappable page nr: %lu, offset: %lu. "
-			__func__, nr_pages_from_vm_start, _dbg_offset_from_page);
+			"Total pages allocated: %ld.\n",
+			__func__, nr_pages_from_vm_start, _dbg_offset_from_page,
+			my_shmem_page_count);
 
 		// We won't delete elements from list here!
 		struct my_shmem_page *page_entry;

src/aarch64-linux-flush-dcache/userspace/writer_addr.c

@@ -0,0 +1,59 @@
+#include <unistd.h>		// sysconf
+#include <stdio.h>		// printf
+#include <stdlib.h>		// exit
+#include <fcntl.h>		// O_RDWR
+#include <sys/mman.h>	// mmap
+#include <string.h>		// strlen
+#include <errno.h>		// errno
+
+#define eprintf(args...) fprintf(stderr, ##args)
+
+const char *DEVICE_PATH = "/dev/my_shmem";
+
+int main(int argc, char *argv[])
+{
+	/* Have:
+	 * - Different mm => different address space
+	 * - Different virtual address
+	 */
+	void *addr = (void *) 0x10000000;
+
+	const long PAGE_SIZE = sysconf(_SC_PAGESIZE);
+	if (PAGE_SIZE == -1) {
+		eprintf("Error retrieving page size: %d.\n", errno);
+		exit(EXIT_FAILURE);
+	}
+
+	// open device file w/ RW perms
+	FILE *fp = fopen(DEVICE_PATH, "r+");
+	if (!fp) {
+		eprintf("Error opening device %s: %d.\n", DEVICE_PATH, errno);
+		exit(EXIT_FAILURE);
+	}
+	int fd = fileno(fp);
+	if (fd == -1) {
+		eprintf("Error retrieving file descriptor: %d.\n", errno);
+		exit(EXIT_FAILURE);
+	}
+
+	// mmap device
+	void *buf = mmap(addr, PAGE_SIZE * 2, PROT_READ | PROT_WRITE,
+		MAP_SHARED, fd, 0);
+	if (!buf) {
+		eprintf("Error mmap-ing: %d.\n", errno);
+		exit(EXIT_FAILURE);
+	}
+
+	// Write to mmap-ed device
+	char to_write[] = {0x88, 0x77, 0x66, 0x55, 0x00};
+	memcpy(buf, to_write, strlen(to_write));
+
+	// Unmap device
+	munmap(buf, PAGE_SIZE * 2);
+
+	// Close device
+	fclose(fp);
+
+	printf("Finished!\n");
+	exit(EXIT_SUCCESS);
+}