Add ko to probe block functions, now submit_bio is probed

Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
This commit is contained in:
Wenchao Hao 2023-03-30 16:28:27 +08:00
parent 89e07d40fe
commit 1fe8fcd630
2 changed files with 56 additions and 0 deletions

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@ -1,6 +1,7 @@
KDIR=/usr/src/kernels/$(shell uname -r) KDIR=/usr/src/kernels/$(shell uname -r)
obj-m += demo.o obj-m += demo.o
obj-m += blk_kprobe.o
all: all:
make -C $(KDIR) M=$(shell pwd) modules make -C $(KDIR) M=$(shell pwd) modules

55
blk_kprobe.c Normal file
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@ -0,0 +1,55 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kprobes.h>
#include <linux/bio.h>
#include <linux/bvec.h>
#include <linux/blkdev.h>
static int submit_bio_pre(struct kprobe *p, struct pt_regs *regs) {
struct bio *bio = (struct bio *)regs->di;
struct bio_vec bvec;
struct bvec_iter iter;
printk(KERN_INFO "submit_bio: bi_vec: bi_vcnt is %d, operation is %s\n", bio->bi_vcnt, blk_op_str(bio_op(bio)));
bio_for_each_bvec(bvec, bio, iter) {
printk(KERN_INFO " idx=%d, sector=%lld, size=%d, done=%d, bv_page=0x%lx, bv_len=%u, bv_offset=%u\n",
iter.bi_idx, iter.bi_sector, iter.bi_size, iter.bi_bvec_done, (unsigned long)bvec.bv_page, bvec.bv_len, bvec.bv_offset);
}
if (bio->bi_vcnt != 1)
dump_stack();
return 0;
}
static struct kprobe submit_bio_kp = {
.symbol_name = "submit_bio",
.pre_handler = submit_bio_pre,
};
static struct kprobe *kprobes[] = {
&submit_bio_kp,
};
static int __init kprobe_init(void) {
int ret;
ret = register_kprobes(kprobes, ARRAY_SIZE(kprobes));
if (ret < 0) {
printk(KERN_INFO "kprobe registration failed\n");
return ret;
}
printk(KERN_INFO "kprobemodule loaded\n");
return 0;
}
static void __exit kprobe_exit(void) {
unregister_kprobes(kprobes, ARRAY_SIZE(kprobes));
printk(KERN_INFO "kprobemodule unloaded\n");
}
module_init(kprobe_init);
module_exit(kprobe_exit);
MODULE_LICENSE("GPL");