Messages in this thread | | | From | Arnd Bergmann <> | Date | Tue, 22 Feb 2022 22:42:22 +0100 | Subject | Re: [PATCH] MIPS: Handle address errors for accesses above CPU max virtual user address |
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On Tue, Feb 22, 2022 at 8:58 PM Thomas Bogendoerfer <tsbogend@alpha.franken.de> wrote: > > On Tue, Feb 22, 2022 at 06:04:07PM +0100, Arnd Bergmann wrote: > > On Tue, Feb 22, 2022 at 4:53 PM Thomas Bogendoerfer > > <tsbogend@alpha.franken.de> wrote: > > > > > > Address errors have always been treated as unaliged accesses and handled > > > as such. But address errors are also issued for illegal accesses like > > > user to kernel space or accesses outside of implemented spaces. This > > > change implements Linux exception handling for accesses to the illegal > > > space above the CPU implemented maximum virtual user address and the > > > MIPS 64bit architecture maximum. With this we can now use a fixed value > > > for the maximum task size on every MIPS CPU and get a more optimized > > > access_ok(). > > > > > > Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> > > > > Thank you for addressing this. Should I add this patch to my series > > ahead of "mips: use simpler access_ok()"? That way I can keep it all > > in my asm-generic tree as a series for 5.18. > > yes please add it to your series.
Done now.
> > > > It might be clearer to use TASK_SIZE_MAX here instead of XKSSEG, > > to match the check in access_ok(). If you like, I can change that while > > applying. > > I had TASK_SIZE_MAX in an intermediate version, but decided to go with XKSSEG, > because it's what this check is about. It's about checking what the MIPS > architecture defined.
Right, makes sense.
Thanks,
Arnd
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