通过配置内核,会在/sys/kernel/debug下产生一个名为kernel_page_tables的文件,查看这个文件可以知道当前内核页表的映射信息。 正文 一、配置内核 首先配置内核,使其支持导出内核页表到debugfs下面: Kernel hacking ---> ---> [*] Export kernel pagetable layout to userspace via debugfs 配置完后,重新编译内核,...
&v5 + off在栈空间中,且off由我们设置,所以我们可以泄漏出canary的值来绕过canary。copy_to_user(v1, (char *)&v5 + off, 64LL)中v1为用户空间的空间地址。 core_copy_func: signed __int64 __fastcall core_copy_func(signed __int64 a1) { signed __int64 result; // rax __int64 v2; // [...
Nov 16 16:26:45 kernel: copyout+0x20/0x30 Nov 16 16:26:45 kernel: _copy_to_iter+0x5e/0x4a0 Nov 16 16:26:45 kernel: copy_page_to_iter+0x8b/0x140 Nov 16 16:26:45 kernel: filemap_read+0x1af/0x320 Nov 16 16:26:45 kernel: vfs_read+0x1b8/0x300 Nov 16 16:26:45 kernel...
No RCU stalls, copy_to_user actions fault correctly in the kernel and free up the CPU again Actual Behavior System locks up. Diagnostic Logs When the kernel is built withCONFIG_RSEQ: [ 1301.906019] rcu: INFO: rcu_sched self-detected stall on CPU [ 1301.907897] rcu: 1-...: (104816 ti...
因此,它只能使用大于PAGE_OFFSET(传统的x86_32上是3G)的地址空间。 内核线程概述 内核线程是直接由内核本身启动的进程。内核线程实际上是将内核函数委托给独立的进程,它与内核中的其他进程”并行”执行。内核线程经常被称之为内核守护进程。 他们执行下列任务 ...
在子线程中,使用 poll函数轮询 uffd,当轮询到缺页事件后,可以先写上自己的处理代码,随后用轮询到的 UFFD_EVENT_PAGEFAULT事件用上述提到的 UFFDIO_COPY拷贝数据到缺页处。 staticvoid*fault_handler_thread(void*arg){// 轮询uffd读到的信息需要存在一个struct uffd_msg对象中staticstructuffd_msgmsg;// ioct...
Copy 8.3.2. The KSM Tuning Service Theksmtunedservice fine-tunes the kernel same-page merging (KSM) configuration by looping and adjustingksm. In addition, theksmtunedservice is notified by libvirt when a guest virtual machine is created or destroyed. Theksmtunedservice ha...
MmGetMdlByteOffset Returns the byte offset within a page of the buffer described by a given MDL. MmGetMdlVirtualAddress Returns a (possibly invalid) virtual address for a buffer described by a given MDL; the returned address, used as an index to a physical address entry in the MDL, can ...
(4)降低访存开销:利用内存大页HUGEPAGE降低TLB miss,利用内存多通道交错访问提高内存访问有效带宽 (5)软件调优:cache行对齐,预取数据,多元数据批量操作 四、XDP 1、XDP简介 XDP(eXpress Data Path)不是一种Kernel Bypass实现方案,与Kernel Bypass实现方式完全相反,是一种依赖于eBPF的内核代码注入技术,能够在网络包到...
The workflow processes described on this page are embodied in workflow tools which perform automated updates to process tasks. No changes to the processes on this page should be made without discussion among the teams affected, including the Release Manager, Stable Kernel Team, Security Team, QA...