linux-kernel - Re: [PATCH] powerpc/32s: Fix module loading failure when VMALLOC

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Message-ID: <874kowwe3o.fsf@igel.home>
Date:   Fri, 21 Aug 2020 11:19:23 +0200
From:   Andreas Schwab <schwab@...ux-m68k.org>
To:     Christophe Leroy <christophe.leroy@...roup.eu>
Cc:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH] powerpc/32s: Fix module loading failure when
 VMALLOC_END is over 0xf0000000

On Aug 21 2020, Christophe Leroy wrote:

> In is_module_segment(), when VMALLOC_END is over 0xf0000000,
> ALIGN(VMALLOC_END, SZ_256M) has value 0.
>
> In that case, addr >= ALIGN(VMALLOC_END, SZ_256M) is always
> true then is_module_segment() always returns false.
>
> Use (ALIGN(VMALLOC_END, SZ_256M) - 1) which will have
> value 0xffffffff and will be suitable for the comparison.
>
> Reported-by: Andreas Schwab <schwab@...ux-m68k.org>
> Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
> Fixes: c49643319715 ("powerpc/32s: Only leave NX unset on segments used for modules")

Thanks, that fixes the crash.

Tested-by: Andreas Schwab <schwab@...ux-m68k.org>

Andreas.

-- 
Andreas Schwab, schwab@...ux-m68k.org
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