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Date:   Wed, 28 Oct 2020 14:29:54 +0100
From:   Joerg Roedel <jroedel@suse.de>
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, x86@kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/mm/ident_map: Check for errors from ident_pud_init()
Message-ID: <20201028132954.GK22179@suse.de>
References: <20201027230648.1885111-1-nivedita@alum.mit.edu>
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On Tue, Oct 27, 2020 at 07:06:48PM -0400, Arvind Sankar wrote:
> Commit
>   ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support")
> added ident_p4d_init() to support 5-level paging, but this function
> doesn't check and return errors from ident_pud_init().
> 
> For example, the decompressor stub uses this code to create an identity
> mapping. If it runs out of pages while trying to allocate a PMD
> pagetable, the error will be currently ignored.
> 
> Fix this to propagate errors.
> 
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
> Fixes: ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support")
> ---
>  arch/x86/mm/ident_map.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)

Reviewed-by: Joerg Roedel <jroedel@suse.de>