Messages in this thread | | | Date | Thu, 24 Feb 2022 10:13:32 -0500 | From | Ross Philipson <> | Subject | Re: [PATCH 1/2] x86/boot: Fix memremap of setup_indirect structures |
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On 2/24/22 08:42, Borislav Petkov wrote: > On Tue, Feb 22, 2022 at 04:01:32PM -0500, Ross Philipson wrote: >> In the ioremap.c module, the check for NULL is only missing in the >> functions we updated but the lack of a check was already there before >> these changes went in. >> >> In the setup.c and e820.c modules, the check for NULL is missing in the >> functions we updated but the lack of a check was already there before >> these changes went in in those functions. The lack of early_memremap() >> NULL checks can also be found in other functions in those modules. > > I don't know how to understand this statement: are you saying that, > because there are other cases where - for whatever reason - the retval > check is not taking place - you should not do it either? > > Because I can see other places where the return value is checked. I > mean, if the return value check doesn't matter, why not make this > function simply void and not bother at all?
Sorry if I am being vague. I will try to clarify.
In the functions I made changes to, some already checked return values from early_memremap and some didn't prior to my changes. In addition, there are other places/functions in those files that did not check return values from early_memremap.
I did a search yesterday and found there are other places where the return value from early_memremap is not checked in files I did not touch. In general the handling of return values from early_memremap is very inconsistent throughout arch/x86.
> >> Fixing it in other functions and possibly elsewhere in the arch/x86 code >> seems to be out of scope for this patch set. We could send separate >> patches and hunt down other places this check is missing. > > That would be appreciated.
I will submit a follow on patch set that chases down all the places where early_memremap return values are not checked and fix them. In addition I will do the same for early_ioremap since it seems to have the same issues throughout arch/x86.
Thanks Ross
> > Thx. >
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