start the big userland migration

userland/README.adoc

@@ -1 +0,0 @@
-https://github.com/cirosantilli/linux-kernel-module-cheat#ansi-c

userland/arch/main.c

@@ -2,10 +2,10 @@
  * https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly-c-standard-library
  */
 
-#include "stdio.h"
-#include "stdint.h"
+#include <stdio.h>
+#include <stdint.h>
 
-#include "lkmc.h"
+#include <lkmc.h>
 
 int asm_main(uint32_t *line);
 

userland/arch/x86_64/freestanding/hello.S

@@ -7,15 +7,15 @@
 _start:
 asm_main_after_prologue:
     /* write */
-    mov $1, %rax    /* stdout */
-    mov $1, %rdi    /* buffer */
-    mov $msg, %rsi  /* len */
-    mov $len, %rdx  /* syscall number */
+    mov $1, %rax    /* syscall number */
+    mov $1, %rdi    /* stdout */
+    mov $msg, %rsi  /* buffer */
+    mov $len, %rdx  /* len */
     syscall
 
     /* exit */
-    mov $60, %rax   /* exit status */
-    mov $0, %rdi    /* syscall number */
+    mov $60, %rax   /* syscall number */
+    mov $0, %rdi    /* exit status */
     syscall
 msg:
     .ascii "hello\n"

userland/c/README.adoc

@@ -0,0 +1 @@
+https://github.com/cirosantilli/linux-kernel-module-cheat#c

userland/cpp/README.adoc

@@ -1 +1 @@
-https://github.com/cirosantilli/linux-kernel-module-cheat#ansi-cpp
+https://github.com/cirosantilli/linux-kernel-module-cheat#cpp

userland/ctrl_alt_del.c

@@ -8,19 +8,19 @@
 #include <unistd.h>
 
 void signal_handler(int sig) {
-	write(STDOUT_FILENO, "cad\n", 4);
-	signal(sig, signal_handler);
+    write(STDOUT_FILENO, "cad\n", 4);
+    signal(sig, signal_handler);
 }
 
 int main(void) {
-	int i = 0;
-	/* Disable the forced reboot, enable sending SIGINT to init. */
-	reboot(RB_DISABLE_CAD);
+    int i = 0;
+    /* Disable the forced reboot, enable sending SIGINT to init. */
+    reboot(RB_DISABLE_CAD);
     signal(SIGINT, signal_handler);
-	while (1) {
-		sleep(1);
-		printf("%d\n", i);
-		i++;
-	}
+    while (1) {
+        sleep(1);
+        printf("%d\n", i);
+        i++;
+    }
     return EXIT_SUCCESS;
 }

userland/gcc/empty_struct.c

@@ -1,4 +1,4 @@
-/* Empty struct */
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#c-empty-struct */
 
 #include <assert.h>
 #include <stdlib.h>

userland/gcc/openmp.c

@@ -0,0 +1,20 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#openmp */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <omp.h>
+
+int main (void) {
+    int nthreads, tid;
+#pragma omp parallel private(nthreads, tid)
+    {
+        tid = omp_get_thread_num();
+        printf("Hello World from thread = %d\n", tid);
+        if (tid == 0) {
+            nthreads = omp_get_num_threads();
+            printf("Number of threads = %d\n", nthreads);
+        }
+    }
+    return EXIT_SUCCESS;
+}

userland/kernel_modules/mmap.c

@@ -0,0 +1,93 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#mmap */
+
+#define _XOPEN_SOURCE 700
+#include <assert.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h> /* uintmax_t */
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h> /* sysconf */
+
+#include <userland/common.h> /* virt_to_phys_user */
+
+enum { BUFFER_SIZE = 4 };
+
+int main(int argc, char **argv) {
+    int fd;
+    long page_size;
+    char *address1, *address2;
+    char buf[BUFFER_SIZE];
+    uintptr_t paddr;
+
+    if (argc < 2) {
+        printf("Usage: %s <mmap_file>\n", argv[0]);
+        return EXIT_FAILURE;
+    }
+    page_size = sysconf(_SC_PAGE_SIZE);
+    printf("open pathname = %s\n", argv[1]);
+    fd = open(argv[1], O_RDWR | O_SYNC);
+    if (fd < 0) {
+        perror("open");
+        assert(0);
+    }
+    printf("fd = %d\n", fd);
+
+    /* mmap twice for double fun. */
+    puts("mmap 1");
+    address1 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (address1 == MAP_FAILED) {
+        perror("mmap");
+        assert(0);
+    }
+    puts("mmap 2");
+    address2 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (address2 == MAP_FAILED) {
+        perror("mmap");
+        return EXIT_FAILURE;
+    }
+    assert(address1 != address2);
+
+    /* Read and modify memory. */
+    puts("access 1");
+    assert(!strcmp(address1, "asdf"));
+    /* vm_fault */
+    puts("access 2");
+    assert(!strcmp(address2, "asdf"));
+    /* vm_fault */
+    strcpy(address1, "qwer");
+    /* Also modified. So both virtual addresses point to the same physical address. */
+    assert(!strcmp(address2, "qwer"));
+
+    /* Check that the physical addresses are the same.
+     * They are, but TODO why virt_to_phys on kernel gives a different value? */
+    assert(!virt_to_phys_user(&paddr, getpid(), (uintptr_t)address1));
+    printf("paddr1 = 0x%jx\n", (uintmax_t)paddr);
+    assert(!virt_to_phys_user(&paddr, getpid(), (uintptr_t)address2));
+    printf("paddr2 = 0x%jx\n", (uintmax_t)paddr);
+
+    /* Check that modifications made from userland are also visible from the kernel. */
+    read(fd, buf, BUFFER_SIZE);
+    assert(!memcmp(buf, "qwer", BUFFER_SIZE));
+
+    /* Modify the data from the kernel, and check that the change is visible from userland. */
+    write(fd, "zxcv", 4);
+    assert(!strcmp(address1, "zxcv"));
+    assert(!strcmp(address2, "zxcv"));
+
+    /* Cleanup. */
+    puts("munmap 1");
+    if (munmap(address1, page_size)) {
+        perror("munmap");
+        assert(0);
+    }
+    puts("munmap 2");
+    if (munmap(address2, page_size)) {
+        perror("munmap");
+        assert(0);
+    }
+    puts("close");
+    close(fd);
+    return EXIT_SUCCESS;
+}

userland/linux/pagemap_dump.c

@@ -0,0 +1,116 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#pagemap_dump-out */
+
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <userland/common.h> /* virt_to_phys_user */
+
+int main(int argc, char **argv) {
+    char buffer[BUFSIZ];
+    char maps_file[BUFSIZ];
+    char pagemap_file[BUFSIZ];
+    int maps_fd;
+    int offset = 0;
+    int pagemap_fd;
+    pid_t pid;
+
+    if (argc < 2) {
+        printf("Usage: %s pid\n", argv[0]);
+        return EXIT_FAILURE;
+    }
+    pid = strtoull(argv[1], NULL, 0);
+    snprintf(maps_file, sizeof(maps_file), "/proc/%ju/maps", (uintmax_t)pid);
+    snprintf(pagemap_file, sizeof(pagemap_file), "/proc/%ju/pagemap", (uintmax_t)pid);
+    maps_fd = open(maps_file, O_RDONLY);
+    if (maps_fd < 0) {
+        perror("open maps");
+        return EXIT_FAILURE;
+    }
+    pagemap_fd = open(pagemap_file, O_RDONLY);
+    if (pagemap_fd < 0) {
+        perror("open pagemap");
+        return EXIT_FAILURE;
+    }
+    printf("vaddr pfn soft-dirty file/shared swapped present library\n");
+    for (;;) {
+        ssize_t length = read(maps_fd, buffer + offset, sizeof buffer - offset);
+        if (length <= 0) break;
+        length += offset;
+        for (size_t i = offset; i < (size_t)length; i++) {
+            uintptr_t low = 0, high = 0;
+            if (buffer[i] == '\n' && i) {
+                const char *lib_name;
+                size_t y;
+                /* Parse a line from maps. Each line contains a range that contains many pages. */
+                {
+                    size_t x = i - 1;
+                    while (x && buffer[x] != '\n') x--;
+                    if (buffer[x] == '\n') x++;
+                    while (buffer[x] != '-' && x < sizeof buffer) {
+                        char c = buffer[x++];
+                        low *= 16;
+                        if (c >= '0' && c <= '9') {
+                            low += c - '0';
+                        } else if (c >= 'a' && c <= 'f') {
+                            low += c - 'a' + 10;
+                        } else {
+                            break;
+                        }
+                    }
+                    while (buffer[x] != '-' && x < sizeof buffer) x++;
+                    if (buffer[x] == '-') x++;
+                    while (buffer[x] != ' ' && x < sizeof buffer) {
+                        char c = buffer[x++];
+                        high *= 16;
+                        if (c >= '0' && c <= '9') {
+                            high += c - '0';
+                        } else if (c >= 'a' && c <= 'f') {
+                            high += c - 'a' + 10;
+                        } else {
+                            break;
+                        }
+                    }
+                    lib_name = 0;
+                    for (int field = 0; field < 4; field++) {
+                        x++;
+                        while(buffer[x] != ' ' && x < sizeof buffer) x++;
+                    }
+                    while (buffer[x] == ' ' && x < sizeof buffer) x++;
+                    y = x;
+                    while (buffer[y] != '\n' && y < sizeof buffer) y++;
+                    buffer[y] = 0;
+                    lib_name = buffer + x;
+                }
+                /* Get info about all pages in this page range with pagemap. */
+                {
+                    PagemapEntry entry;
+                    for (uintptr_t vaddr = low; vaddr < high; vaddr += sysconf(_SC_PAGE_SIZE)) {
+                        /* TODO always fails for the last page (vsyscall), why? pread returns 0. */
+                        if (!pagemap_get_entry(&entry, pagemap_fd, vaddr)) {
+                            printf(
+                                "%jx %jx %u %u %u %u %s\n",
+                                (uintmax_t)vaddr,
+                                (uintmax_t)entry.pfn,
+                                entry.soft_dirty,
+                                entry.file_page,
+                                entry.swapped,
+                                entry.present,
+                                lib_name
+                            );
+                        }
+                    }
+                }
+                buffer[y] = '\n';
+            }
+        }
+    }
+    close(maps_fd);
+    close(pagemap_fd);
+    return EXIT_SUCCESS;
+}

userland/linux/virt_to_phys_user.c

@@ -0,0 +1,25 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-physical-address-experiments */
+
+#define _XOPEN_SOURCE 700
+#include <stdio.h> /* printf */
+#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE, strtoull */
+
+#include <userland/common.h> /* virt_to_phys_user */
+
+int main(int argc, char **argv) {
+    pid_t pid;
+    uintptr_t vaddr, paddr = 0;
+
+    if (argc < 3) {
+        printf("Usage: %s pid vaddr\n", argv[0]);
+        return EXIT_FAILURE;
+    }
+    pid = strtoull(argv[1], NULL, 0);
+    vaddr = strtoull(argv[2], NULL, 0);
+    if (virt_to_phys_user(&paddr, pid, vaddr)) {
+        fprintf(stderr, "error: virt_to_phys_user\n");
+        return EXIT_FAILURE;
+    };
+    printf("0x%jx\n", (uintmax_t)paddr);
+    return EXIT_SUCCESS;
+}

userland/mmap.c

@@ -1,94 +0,0 @@
-/* https://github.com/cirosantilli/linux-kernel-module-cheat#mmap */
-
-#define _XOPEN_SOURCE 700
-#include <assert.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdint.h> /* uintmax_t */
-#include <string.h>
-#include <sys/mman.h>
-#include <unistd.h> /* sysconf */
-
-#include "common_userland.h" /* virt_to_phys_user */
-
-enum { BUFFER_SIZE = 4 };
-
-int main(int argc, char **argv)
-{
-	int fd;
-	long page_size;
-	char *address1, *address2;
-	char buf[BUFFER_SIZE];
-	uintptr_t paddr;
-
-	if (argc < 2) {
-		printf("Usage: %s <mmap_file>\n", argv[0]);
-		return EXIT_FAILURE;
-	}
-	page_size = sysconf(_SC_PAGE_SIZE);
-	printf("open pathname = %s\n", argv[1]);
-	fd = open(argv[1], O_RDWR | O_SYNC);
-	if (fd < 0) {
-		perror("open");
-		assert(0);
-	}
-	printf("fd = %d\n", fd);
-
-    /* mmap twice for double fun. */
-	puts("mmap 1");
-	address1 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (address1 == MAP_FAILED) {
-		perror("mmap");
-		assert(0);
-	}
-	puts("mmap 2");
-	address2 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (address2 == MAP_FAILED) {
-		perror("mmap");
-		return EXIT_FAILURE;
-	}
-	assert(address1 != address2);
-
-    /* Read and modify memory. */
-	puts("access 1");
-	assert(!strcmp(address1, "asdf"));
-	/* vm_fault */
-	puts("access 2");
-	assert(!strcmp(address2, "asdf"));
-	/* vm_fault */
-	strcpy(address1, "qwer");
-	/* Also modified. So both virtual addresses point to the same physical address. */
-	assert(!strcmp(address2, "qwer"));
-
-	/* Check that the physical addresses are the same.
-	 * They are, but TODO why virt_to_phys on kernel gives a different value? */
-	assert(!virt_to_phys_user(&paddr, getpid(), (uintptr_t)address1));
-	printf("paddr1 = 0x%jx\n", (uintmax_t)paddr);
-	assert(!virt_to_phys_user(&paddr, getpid(), (uintptr_t)address2));
-	printf("paddr2 = 0x%jx\n", (uintmax_t)paddr);
-
-    /* Check that modifications made from userland are also visible from the kernel. */
-	read(fd, buf, BUFFER_SIZE);
-	assert(!memcmp(buf, "qwer", BUFFER_SIZE));
-
-	/* Modify the data from the kernel, and check that the change is visible from userland. */
-	write(fd, "zxcv", 4);
-	assert(!strcmp(address1, "zxcv"));
-	assert(!strcmp(address2, "zxcv"));
-
-    /* Cleanup. */
-    puts("munmap 1");
-	if (munmap(address1, page_size)) {
-		perror("munmap");
-		assert(0);
-	}
-    puts("munmap 2");
-	if (munmap(address2, page_size)) {
-		perror("munmap");
-		assert(0);
-	}
-    puts("close");
-	close(fd);
-	return EXIT_SUCCESS;
-}

userland/openblas_hello.c

@@ -1,15 +1,39 @@
 /* https://github.com/cirosantilli/linux-kernel-module-cheat#blas
- * Adapted from: https://github.com/xianyi/OpenBLAS/wiki/User-Manual/59b62f98e7400270fb03ad1d85fba5b64ebbff2b#call-cblas-interface */
-
-#include "lkmc.h"
+ * Adapted from: https://github.com/xianyi/OpenBLAS/wiki/User-Manual/59b62f98e7400270fb03ad1d85fba5b64ebbff2b#call-cblas-interface
+ */
 
 #include <assert.h>
 #include <cblas.h>
 
+#include <lkmc.h>
+
 int main(void) {
-    double A[6] = {1.0, 2.0, 1.0, -3.0, 4.0, -1.0};
-    double B[6] = {1.0, 2.0, 1.0, -3.0, 4.0, -1.0};
-    double C[9] = {0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5};
-    cblas_dgemm(CblasColMajor, CblasNoTrans, CblasTrans, 3, 3, 2, 1, A, 3, B, 3, 2, C, 3);
-    assert(lkmc_vector_equal(9, C, (double[]){11.0, -9.0, 5.0, -9.0, 21.0, -1.0, 5.0, -1.0, 3.0}, 1e-6));
+    double A[6] = {
+         1.0, 2.0,  1.0,
+        -3.0, 4.0, -1.0
+    };
+    double B[6] = {
+         1.0,  2.0,
+         1.0, -3.0,
+         4.0, -1.0
+    };
+    double C[9] = {
+        0.5, 0.5, 0.5,
+        0.5, 0.5, 0.5,
+        0.5, 0.5, 0.5
+    };
+    cblas_dgemm(
+        CblasColMajor, CblasNoTrans, CblasTrans,
+        3, 3, 2, 1, A, 3, B, 3, 2, C, 3
+    );
+    assert(lkmc_vector_equal(
+        9,
+        C,
+        (double[]) {
+            11.0, -9.0,  5.0,
+            -9.0, 21.0, -1.0,
+             5.0, -1.0,  3.0
+        },
+        1e-6
+    ));
 }

userland/openmp.c

@@ -1,19 +0,0 @@
-/* https://github.com/cirosantilli/linux-kernel-module-cheat#openmp */
-
-#include <omp.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-int main () {
-	int nthreads, tid;
-#pragma omp parallel private(nthreads, tid)
-	{
-		tid = omp_get_thread_num();
-		printf("Hello World from thread = %d\n", tid);
-		if (tid == 0) {
-			nthreads = omp_get_num_threads();
-			printf("Number of threads = %d\n", nthreads);
-		}
-	}
-	return EXIT_SUCCESS;
-}

userland/pagemap_dump.c

@@ -1,116 +0,0 @@
-/* https://github.com/cirosantilli/linux-kernel-module-cheat#pagemap_dump-out */
-
-#define _XOPEN_SOURCE 700
-#include <errno.h>
-#include <fcntl.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include "common_userland.h" /* pagemap_get_entry */
-
-int main(int argc, char **argv)
-{
-	char buffer[BUFSIZ];
-	char maps_file[BUFSIZ];
-	char pagemap_file[BUFSIZ];
-	int maps_fd;
-	int offset = 0;
-	int pagemap_fd;
-	pid_t pid;
-
-	if (argc < 2) {
-		printf("Usage: %s pid\n", argv[0]);
-		return EXIT_FAILURE;
-	}
-	pid = strtoull(argv[1], NULL, 0);
-	snprintf(maps_file, sizeof(maps_file), "/proc/%ju/maps", (uintmax_t)pid);
-	snprintf(pagemap_file, sizeof(pagemap_file), "/proc/%ju/pagemap", (uintmax_t)pid);
-	maps_fd = open(maps_file, O_RDONLY);
-	if (maps_fd < 0) {
-		perror("open maps");
-		return EXIT_FAILURE;
-	}
-	pagemap_fd = open(pagemap_file, O_RDONLY);
-	if (pagemap_fd < 0) {
-		perror("open pagemap");
-		return EXIT_FAILURE;
-	}
-	printf("vaddr pfn soft-dirty file/shared swapped present library\n");
-	for (;;) {
-		ssize_t length = read(maps_fd, buffer + offset, sizeof buffer - offset);
-		if (length <= 0) break;
-		length += offset;
-		for (size_t i = offset; i < (size_t)length; i++) {
-			uintptr_t low = 0, high = 0;
-			if (buffer[i] == '\n' && i) {
-				const char *lib_name;
-				size_t y;
-				/* Parse a line from maps. Each line contains a range that contains many pages. */
-				{
-					size_t x = i - 1;
-					while (x && buffer[x] != '\n') x--;
-					if (buffer[x] == '\n') x++;
-					while (buffer[x] != '-' && x < sizeof buffer) {
-						char c = buffer[x++];
-						low *= 16;
-						if (c >= '0' && c <= '9') {
-							low += c - '0';
-						} else if (c >= 'a' && c <= 'f') {
-							low += c - 'a' + 10;
-						} else {
-						    break;
-						}
-					}
-					while (buffer[x] != '-' && x < sizeof buffer) x++;
-					if (buffer[x] == '-') x++;
-					while (buffer[x] != ' ' && x < sizeof buffer) {
-						char c = buffer[x++];
-						high *= 16;
-						if (c >= '0' && c <= '9') {
-							high += c - '0';
-						} else if (c >= 'a' && c <= 'f') {
-							high += c - 'a' + 10;
-						} else {
-							break;
-						}
-					}
-					lib_name = 0;
-					for (int field = 0; field < 4; field++) {
-						x++;
-						while(buffer[x] != ' ' && x < sizeof buffer) x++;
-					}
-					while (buffer[x] == ' ' && x < sizeof buffer) x++;
-					y = x;
-					while (buffer[y] != '\n' && y < sizeof buffer) y++;
-					buffer[y] = 0;
-					lib_name = buffer + x;
-				}
-				/* Get info about all pages in this page range with pagemap. */
-				{
-					PagemapEntry entry;
-					for (uintptr_t vaddr = low; vaddr < high; vaddr += sysconf(_SC_PAGE_SIZE)) {
-						/* TODO always fails for the last page (vsyscall), why? pread returns 0. */
-						if (!pagemap_get_entry(&entry, pagemap_fd, vaddr)) {
-							printf("%jx %jx %u %u %u %u %s\n",
-								(uintmax_t)vaddr,
-								(uintmax_t)entry.pfn,
-								entry.soft_dirty,
-								entry.file_page,
-								entry.swapped,
-								entry.present,
-								lib_name
-							);
-						}
-					}
-				}
-				buffer[y] = '\n';
-			}
-		}
-	}
-	close(maps_fd);
-	close(pagemap_fd);
-	return EXIT_SUCCESS;
-}

userland/posix/count.c

@@ -1,4 +1,6 @@
-/* Count to infinity with 1 second sleep between each increment. */
+/* Count to infinity with 1 second sleep between each increment.
+ * Sample application: https://github.com/cirosantilli/linux-kernel-module-cheat#gdb-step-debug-userland-custom-init
+ */
 
 #define _XOPEN_SOURCE 700
 #include <limits.h>

userland/virt_to_phys_user.c

@@ -1,26 +0,0 @@
-/* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-physical-address-experiments */
-
-#define _XOPEN_SOURCE 700
-#include <stdio.h> /* printf */
-#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE, strtoull */
-
-#include "common_userland.h" /* virt_to_phys_user */
-
-int main(int argc, char **argv)
-{
-	pid_t pid;
-	uintptr_t vaddr, paddr = 0;
-
-	if (argc < 3) {
-		printf("Usage: %s pid vaddr\n", argv[0]);
-		return EXIT_FAILURE;
-	}
-	pid = strtoull(argv[1], NULL, 0);
-	vaddr = strtoull(argv[2], NULL, 0);
-	if (virt_to_phys_user(&paddr, pid, vaddr)) {
-		fprintf(stderr, "error: virt_to_phys_user\n");
-		return EXIT_FAILURE;
-	};
-	printf("0x%jx\n", (uintmax_t)paddr);
-	return EXIT_SUCCESS;
-}