From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC PATCH v8 08/14] arm64/mm: disable section/contiguous mappings if XPFO is enabled References: <0b9624b6c1fe5a31d73a6390e063d551bfebc321.1550088114.git.khalid.aziz@oracle.com> <20190215130942.GD53520@lakrids.cambridge.arm.com> From: Khalid Aziz Message-ID: <259cac45-3337-d446-5abc-21b694d916e1@oracle.com> Date: Fri, 15 Feb 2019 07:47:37 -0700 MIME-Version: 1.0 In-Reply-To: <20190215130942.GD53520@lakrids.cambridge.arm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable To: Mark Rutland Cc: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de, ak@linux.intel.com, torvalds@linux-foundation.org, liran.alon@oracle.com, keescook@google.com, akpm@linux-foundation.org, mhocko@suse.com, catalin.marinas@arm.com, will.deacon@arm.com, jmorris@namei.org, konrad.wilk@oracle.com, Tycho Andersen , deepa.srinivasan@oracle.com, chris.hyser@oracle.com, tyhicks@canonical.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.com, jcm@redhat.com, boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com, joao.m.martins@oracle.com, jmattson@google.com, pradeep.vincent@oracle.com, john.haxby@oracle.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de, steven.sistare@oracle.com, labbott@redhat.com, luto@kernel.org, dave.hansen@intel.com, peterz@infradead.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-ID: On 2/15/19 6:09 AM, Mark Rutland wrote: > Hi, >=20 > On Wed, Feb 13, 2019 at 05:01:31PM -0700, Khalid Aziz wrote: >> From: Tycho Andersen >> >> XPFO doesn't support section/contiguous mappings yet, so let's disable= it >> if XPFO is turned on. >> >> Thanks to Laura Abbot for the simplification from v5, and Mark Rutland= for >> pointing out we need NO_CONT_MAPPINGS too. >> >> CC: linux-arm-kernel@lists.infradead.org >> Signed-off-by: Tycho Andersen >> Reviewed-by: Khalid Aziz >=20 > There should be no point in this series where it's possible to enable a= > broken XPFO. Either this patch should be merged into the rest of the > arm64 bits, or it should be placed before the rest of the arm64 bits. >=20 > That's a pre-requisite for merging, and it significantly reduces the > burden on reviewers. >=20 > In general, a patch series should bisect cleanly. Could you please > restructure the series to that effect? >=20 > Thanks, > Mark. That sounds reasonable to me. I will merge this with patch 5 ("arm64/mm: Add support for XPFO") for the next version unless there are objections. Thanks, Khalid >=20 >> --- >> arch/arm64/mm/mmu.c | 2 +- >> include/linux/xpfo.h | 4 ++++ >> mm/xpfo.c | 6 ++++++ >> 3 files changed, 11 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >> index d1d6601b385d..f4dd27073006 100644 >> --- a/arch/arm64/mm/mmu.c >> +++ b/arch/arm64/mm/mmu.c >> @@ -451,7 +451,7 @@ static void __init map_mem(pgd_t *pgdp) >> struct memblock_region *reg; >> int flags =3D 0; >> =20 >> - if (debug_pagealloc_enabled()) >> + if (debug_pagealloc_enabled() || xpfo_enabled()) >> flags =3D NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; >> =20 >> /* >> diff --git a/include/linux/xpfo.h b/include/linux/xpfo.h >> index 1ae05756344d..8b029918a958 100644 >> --- a/include/linux/xpfo.h >> +++ b/include/linux/xpfo.h >> @@ -47,6 +47,8 @@ void xpfo_temp_map(const void *addr, size_t size, vo= id **mapping, >> void xpfo_temp_unmap(const void *addr, size_t size, void **mapping, >> size_t mapping_len); >> =20 >> +bool xpfo_enabled(void); >> + >> #else /* !CONFIG_XPFO */ >> =20 >> static inline void xpfo_kmap(void *kaddr, struct page *page) { } >> @@ -69,6 +71,8 @@ static inline void xpfo_temp_unmap(const void *addr,= size_t size, >> } >> =20 >> =20 >> +static inline bool xpfo_enabled(void) { return false; } >> + >> #endif /* CONFIG_XPFO */ >> =20 >> #endif /* _LINUX_XPFO_H */ >> diff --git a/mm/xpfo.c b/mm/xpfo.c >> index 92ca6d1baf06..150784ae0f08 100644 >> --- a/mm/xpfo.c >> +++ b/mm/xpfo.c >> @@ -71,6 +71,12 @@ struct page_ext_operations page_xpfo_ops =3D { >> .init =3D init_xpfo, >> }; >> =20 >> +bool __init xpfo_enabled(void) >> +{ >> + return !xpfo_disabled; >> +} >> +EXPORT_SYMBOL(xpfo_enabled); >> + >> static inline struct xpfo *lookup_xpfo(struct page *page) >> { >> struct page_ext *page_ext =3D lookup_page_ext(page); >> --=20 >> 2.17.1 >>