mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
synced 2026-01-13 20:12:26 +00:00
fd55d694c0
Unsquashed version at v2-rc-unsquashed, but that cannot be merged as it breaks bisects at several points. All bugs will not bisect to this humongous change. It all started with a conversion of the Bash scripts to Python, mainly because I couldn't stand not being able to properly use --options for run which has a million options. Then since that required a full testing, I decided to do all the refactorings that I had in mind at once, and so I did and it became v2-rc. This is the largest patch I have ever done! OMG a few weeks of extra time. I'm never writing a Bash script for anything that starts getting big again. Some of the features are: * separate build-qemu and build-gem5 commands * common: convert scripts to python. Add --option for everything * rename build to build-buildroot now that we are splitting all the build commands, Linux kernel to follow * move all git submodules to submodules/ and all buildroot packages to packages/ * refactor the out/ structure. Keep projects on toplevel, because guest projects separate archs and host ones don't, making a toplevel arch wrong * do-release: rename to just release https://stackoverflow.com/questions/16174992/cant-get-argparse-to-read-quoted-string-with-dashes-in-it * run: add --terminal and explain gem5 pdb * just track the lvimrc * store CLI kernel config fragment inside buildlroot to avoid conflicts * gem5: document m5 initparam * readme: make a bunch of things awesomer * readme: fix broken refs * parsec-benchmark: update to 75d55ac446a43c47efb1044844a108c6c330184c Could not fetch otherwise. * gem5: M5_OVERRIDE_PY_SOURCE
68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
/* https://github.com/cirosantilli/linux-kernel-module-cheat#debugfs */
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#include <linux/debugfs.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <uapi/linux/stat.h> /* S_IRUSR */
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static struct dentry *dir, *toplevel_file;
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static u32 value = 42;
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/* This basically re-implents the write operation of debugfs_create_u32,
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* it is just an excuse to illustrate a fop. */
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static ssize_t write(struct file *filp, const char __user *buf, size_t len, loff_t *off)
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{
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int ret;
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unsigned long long res;
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/* https://stackoverflow.com/questions/6139493/how-convert-char-to-int-in-linux-kernel */
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ret = kstrtoull_from_user(buf, len, 10, &res);
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if (ret) {
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/* Negative error code. */
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return ret;
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} else {
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value = res;
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*off= len;
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return len;
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}
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}
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static const struct file_operations fops = {
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.owner = THIS_MODULE,
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.write = write,
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};
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static int myinit(void)
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{
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struct dentry *file;
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dir = debugfs_create_dir("lkmc_debugfs", 0);
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if (!dir) {
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pr_alert("debugfs_create_dir failed");
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return -1;
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}
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file = debugfs_create_u32("myfile", S_IRUSR | S_IWUSR, dir, &value);
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if (!file) {
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pr_alert("debugfs_create_u32 failed");
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return -1;
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}
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/* Created on the toplevel of the debugfs mount,
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* and with explicit fops instead of a fixed integer value.
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*/
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toplevel_file = debugfs_create_file(
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"lkmc_debugfs_file", S_IWUSR, NULL, NULL, &fops);
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if (!toplevel_file) {
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return -1;
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}
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return 0;
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}
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static void myexit(void)
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{
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debugfs_remove_recursive(dir);
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debugfs_remove(toplevel_file);
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}
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module_init(myinit)
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module_exit(myexit)
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MODULE_LICENSE("GPL");
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