• J
    bpf: add a bpf_override_regs helper · e05ebae4
    JqyangCode 提交于
    openeuler inclusion
    category: feature
    bugzilla: https://gitee.com/open_euler/dashboard?issue_id=I55FLX
    CVE: NA
    
    Reference: NA
    
    -------------------
    
    Error injection is a very important method for testing system stability. But for now,
    it is still lacking in this regard, but BPF can fill this gap perfectly with its kprobe
    function.
    
    We can use some validation methods to ensure that it only fires on calls we restrict.
    Although there are bpf_override_funciton that can complete some related operations
    before, this is a function that bypasses the initial detection and only modifies the
    return value to the specified value.This does not meet some of our practical scenarios:
    
    1. For example, other registers (such as input registers) need to be modified: when we
    receive a network packet, we will convert it into a structure and pass it to the corresponding
    function for processing.For the fault tolerance of network data, we need to modify the
    members of this structure, which it cannot do.
    
    2. The function cannot be mounted or what needs to be modified is not the function but the
    instruction: when the sensor reads the IO data, we need to simulate the IO data error.
    At this time, the reading of the IO data may not be a function, but a few simple instructions
    
    In summary, it is necessary to extend an interface that can modify any register, which can
    provide us with a simple way to achieve system error injection
    Signed-off-by: NJqyangCode <teanix@163.com>
    e05ebae4
error-injection.h 1.2 KB