3rd-party/linux-kernel-module-cheat
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This commit is contained in:
Ciro Santilli
2017-06-08 06:26:20 +01:00
parent 41dbf46531
commit 4c1b0e7891
7 changed files with 85 additions and 85 deletions
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26
kernel_module/debugfs.c
View File

@@ -19,23 +19,23 @@ static u32 value = 42;
static int myinit(void) static int myinit(void)
{ {
struct dentry *file; struct dentry *file;
dir = debugfs_create_dir("lkmc_debugfs", 0); dir = debugfs_create_dir("lkmc_debugfs", 0);
if (!dir) { if (!dir) {
printk(KERN_ALERT "debugfs_create_dir failed"); printk(KERN_ALERT "debugfs_create_dir failed");
return -1; return -1;
} }
file = debugfs_create_u32("myfile", 0666, dir, &value); file = debugfs_create_u32("myfile", 0666, dir, &value);
if (!file) { if (!file) {
printk(KERN_ALERT "debugfs_create_u32 failed"); printk(KERN_ALERT "debugfs_create_u32 failed");
return -1; return -1;
} }
return 0; return 0;
} }
static void myexit(void) static void myexit(void)
{ {
debugfs_remove_recursive(dir); debugfs_remove_recursive(dir);
} }
module_init(myinit) module_init(myinit)

52
kernel_module/dep.c
View File

@@ -1,38 +1,38 @@
/* /*
Exports the lkmc_dep which dep2.ko uses. Exports the lkmc_dep which dep2.ko uses.
insmod /dep.ko insmod /dep.ko
# dmesg => 0 # dmesg => 0
# dmesg => 0 # dmesg => 0
# dmesg => ... # dmesg => ...
insmod /dep2.ko insmod /dep2.ko
# dmesg => 1 # dmesg => 1
# dmesg => 2 # dmesg => 2
# dmesg => ... # dmesg => ...
rmmod dep rmmod dep
# Fails because dep2 uses it. # Fails because dep2 uses it.
rmmod dep2 rmmod dep2
# Dmesg stops incrementing. # Dmesg stops incrementing.
rmmod dep rmmod dep
sys visibility: sys visibility:
dmesg -n 1 dmesg -n 1
insmod /dep.ko insmod /dep.ko
insmod /dep2.ko insmod /dep2.ko
ls -l /sys/module/dep/holders ls -l /sys/module/dep/holders
# => ../../dep2 # => ../../dep2
cat refcnt cat refcnt
# => 1 # => 1
depmod: depmod:
grep dep "/lib/module/"*"/depmod" grep dep "/lib/module/"*"/depmod"
# extra/dep2.ko: extra/dep.ko # extra/dep2.ko: extra/dep.ko
# extra/dep.ko: # extra/dep.ko:
modprobe dep modprobe dep
# lsmod # lsmod
# Both dep and dep2 were loaded. # Both dep and dep2 were loaded.
TODO: at what point does buildroot / busybox generate that file? TODO: at what point does buildroot / busybox generate that file?
*/ */

2
kernel_module/fops.c
View File

@@ -144,7 +144,7 @@ static int myinit(void)
printk(KERN_ALERT "debugfs_create_dir failed"); printk(KERN_ALERT "debugfs_create_dir failed");
return -1; return -1;
} }
file = debugfs_create_file("f", 0666, dir, NULL, &fops); file = debugfs_create_file("f", 0666, dir, NULL, &fops);
if (!file) { if (!file) {
printk(KERN_ALERT "debugfs_create_file failed"); printk(KERN_ALERT "debugfs_create_file failed");
return -1; return -1;

4
kernel_module/irq.c
View File

@@ -13,8 +13,8 @@ MODULE_LICENSE("GPL");
* Return value from kernel docs:* * Return value from kernel docs:*
* *
* enum irqreturn * enum irqreturn
* @IRQ_NON interrupt was not from this device or was not handled * @IRQ_NON interrupt was not from this device or was not handled
* @IRQ_HANDLED interrupt was handled by this device * @IRQ_HANDLED interrupt was handled by this device
* @IRQ_WAKE_THREAD handler requests to wake the handler thread * @IRQ_WAKE_THREAD handler requests to wake the handler thread
*/ */
static irqreturn_t handler(int i, void *v) static irqreturn_t handler(int i, void *v)

28
kernel_module/test/myinsmod.c
View File

@@ -12,23 +12,23 @@
int main(int argc, char **argv) { int main(int argc, char **argv) {
size_t image_size; size_t image_size;
void *image; void *image;
int fd; int fd;
struct stat st; struct stat st;
if (argc != 2) { if (argc != 2) {
puts("Usage ./prog mymodule.ko"); puts("Usage ./prog mymodule.ko");
return EXIT_FAILURE; return EXIT_FAILURE;
} }
fd = open(argv[1], O_RDONLY); fd = open(argv[1], O_RDONLY);
fstat(fd, &st); fstat(fd, &st);
image_size = st.st_size; image_size = st.st_size;
image = malloc(image_size); image = malloc(image_size);
read(fd, image, image_size); read(fd, image, image_size);
close(fd); close(fd);
if (init_module(image, image_size, "") != 0) { if (init_module(image, image_size, "") != 0) {
perror("init_module"); perror("init_module");
return EXIT_FAILURE; return EXIT_FAILURE;
} }
free(image); free(image);
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }

10
kernel_module/test/myrmmod.c
View File

@@ -14,9 +14,9 @@ int main(int argc, char **argv) {
puts("Usage ./prog mymodule"); puts("Usage ./prog mymodule");
return EXIT_FAILURE; return EXIT_FAILURE;
} }
if (delete_module(argv[1], O_NONBLOCK) != 0) { if (delete_module(argv[1], O_NONBLOCK) != 0) {
perror("delete_module"); perror("delete_module");
return EXIT_FAILURE; return EXIT_FAILURE;
} }
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }

48
kernel_module/test/poll.c
View File

@@ -6,29 +6,29 @@
#include <unistd.h> /* read */ #include <unistd.h> /* read */
int main(int argc, char **argv) { int main(int argc, char **argv) {
char buf[1024], path[1024]; char buf[1024], path[1024];
int fd, i, n; int fd, i, n;
short revents; short revents;
struct pollfd pfd; struct pollfd pfd;
fd = open(argv[1], O_RDONLY | O_NONBLOCK); fd = open(argv[1], O_RDONLY | O_NONBLOCK);
if (fd == -1) { if (fd == -1) {
perror("open"); perror("open");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
pfd.fd = fd; pfd.fd = fd;
pfd.events = POLLIN; pfd.events = POLLIN;
while (1) { while (1) {
puts("loop"); puts("loop");
i = poll(&pfd, 1, -1); i = poll(&pfd, 1, -1);
if (i == -1) { if (i == -1) {
perror("poll"); perror("poll");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
revents = pfd.revents; revents = pfd.revents;
if (revents & POLLIN) { if (revents & POLLIN) {
n = read(pfd.fd, buf, sizeof(buf)); n = read(pfd.fd, buf, sizeof(buf));
printf("POLLIN n=%d buf=%.*s\n", n, n, buf); printf("POLLIN n=%d buf=%.*s\n", n, n, buf);
} }
} }
} }