From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 7 Nov 2018 21:58:46 +0000 Subject: [PATCH 2/7] arm64: sdei: Always use sdei stack for sdei events In-Reply-To: <1537970184-44348-3-git-send-email-julien.thierry@arm.com> References: <1537970184-44348-1-git-send-email-julien.thierry@arm.com> <1537970184-44348-3-git-send-email-julien.thierry@arm.com> Message-ID: <20181107215844.GC12248@brain-police> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Sep 26, 2018 at 02:56:19PM +0100, Julien Thierry wrote: > SDEI events can occur at any point, including when the stack pointer is > not aligned. SP could be modified to respect alignment 16-byte alignement, > but there is a need to deal with code using SP as scratch register. > > Always reserve the SDEI stacks to handle its events. > > Since stack allocation relies on VMAPed stacks, lets make SDEI depend on > VMAP_STACK. > > Signed-off-by: Julien Thierry > --- > arch/arm64/include/asm/sdei.h | 2 -- > arch/arm64/kernel/entry.S | 2 -- > arch/arm64/kernel/sdei.c | 23 ++++++++--------------- > drivers/firmware/Kconfig | 1 + > 4 files changed, 9 insertions(+), 19 deletions(-) One side-effect of this change is that SDEI cannot be enabled in conjunction with KASAN. James -- are you ok with that? Will