Messages in this thread |  | | Date | Fri, 24 Jan 1997 23:58:51 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: This can freeze linux 2.0 on 486 |
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On Fri, 24 Jan 1997, Praveen Dwivedi wrote:
> Hi all, > > Recently I saw this behaviour on linux 2.0 running on i486. > > Instruction invd ( supposed to invalidate cache) can lock the m/c > completely. > > Put Instruction invd in assembly file, assemble and link and > see the consequences. I am not sure whether this is a 486 bug or > linux bug. > > BTW invd is a privileged instruction on Pentium I am not sure > about 486. > > -pkd > -- > > ---------------------------------------------------------------------- > Praveen Dwivedi pkd@sequent.com > -- > This IS a privileged instruction. It is supposed to generate a trap from user-mode code. I will try this at home on a 486.
The trap that is supposed to be executed, int 13h, might point to bad code in the kernel, causing the hang. This could be due to a bad link when compiled. If the opcode is executed in kernel mode, it will just flush the cache with no long-standing effects, so I think that code at the trap address might be the problem.
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