From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: [PATCH 16/18] arm: clarify comment about exception stack use Date: Sun, 1 Feb 2015 19:34:44 +0100 Message-ID: <1422815686-24591-17-git-send-email-drjones@redhat.com> References: <1422815686-24591-1-git-send-email-drjones@redhat.com> Cc: christoffer.dall@linaro.org, pbonzini@redhat.com To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:41702 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754012AbbBASfQ (ORCPT ); Sun, 1 Feb 2015 13:35:16 -0500 In-Reply-To: <1422815686-24591-1-git-send-email-drjones@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Each mode has its own stack, but we only use it as a base pointer to a private memory region. That region, which has a size of sizeof(struct pt_regs), is used to store some registers during the switch to svc mode - which will use the normal svc stack. The switch to svc mode is done because we handle all exceptions in svc. Signed-off-by: Andrew Jones --- arm/cstart.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arm/cstart.S b/arm/cstart.S index fd02aaab268d7..08a0b3ecc61f6 100644 --- a/arm/cstart.S +++ b/arm/cstart.S @@ -121,8 +121,9 @@ asm_mmu_enable: * Simplified version of the Linux kernel implementation * arch/arm/kernel/entry-armv.S * - * Each mode has an S_FRAME_SIZE sized stack initialized - * in exceptions_init + * Each mode has an S_FRAME_SIZE sized memory region, + * and the mode's stack pointer has been initialized + * to the base of that region in exceptions_init. */ .macro vector_stub, name, vec, mode, correction=0 .align 5 -- 1.9.3