symbol versions

[Albert D. Cahalan]

Why doesn't the System.map file get mangled in the same way as
the /proc/ksyms file does? The unpredictable mangling makes it
impossible to verify that a System.map matches the running kernel.

Examples:

  video_font_height
  video_font_height_R2gig_65e24198

  scsi_request_queueable
  scsi_request_queueable_Rsmp_7ca0aa89

What can be done?

*  mangle both
*  always mangle /proc/ksyms in a predictable manner
*  add a shared 128-bit random cookie

Without some changes, it is very difficult to detect mismatch.
The kernel version number is not enough. It is common for people
to compile a new kernel for a fresh system, with the same version
number as the distribution kernel, and forget to update System.map.
People use "ps l" to report where a process is stuck in the kernel.
I don't wish to have users reporting bugs in the wrong driver.