Re: [CFT] error checking for VM86 instruction emulation

[Stas Sergeev]

Manfred Spraul wrote:
> The emulation code for the instructions that cannot be executed in vm86
> mode directly (iretd, pushf and a few others) accesses user space memory
> without an exception handler. This can cause a kernel oops if the stack
> pointer points to non-present or read-only memory areas.
> 
> The attached patch adds these handlers, but I can't test them properly.
> Under 2.5.2-pre1, dosemu still runs.
> 
> The patch applies to both 2.4.17 and 2.2.20. Please test it.
It works. The Oops is no longer reproduceable at all (it was 100% reproduceable
before) so I vote for integrating this patch into kernel:)

Thank you.