From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anton Blanchard , Michael Ellerman Subject: [PATCH 3.18 115/183] powernv: Fix OPAL tracepoint code Date: Sun, 25 Jan 2015 10:07:17 -0800 Message-Id: <20150125180815.190200481@linuxfoundation.org> In-Reply-To: <20150125180810.160428929@linuxfoundation.org> References: <20150125180810.160428929@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anton Blanchard commit bfe5fda8e7ced129716f5741cf7ed2592a338824 upstream. Patch c49f63530bb6 ("powernv: Add OPAL tracepoints") has a spurious store to the stack: ld r12,opal_tracepoint_refcount@toc(r2); \ std r12,32(r1); \ The store was originally used to save the current tracepoint status so the entry and the exit tracepoints were always balanced. In the end I just created a separate path when tracepoints are enabled. The offset on the stack used for this store is not valid for ABIv2 and it causes strange issues. I noticed it because OPAL console input was broken. Fixes: c49f63530bb6 ("powernv: Add OPAL tracepoints") Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/opal-wrappers.S | 1 - 1 file changed, 1 deletion(-) --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -40,7 +40,6 @@ BEGIN_FTR_SECTION; \ b 1f; \ END_FTR_SECTION(0, 1); \ ld r12,opal_tracepoint_refcount@toc(r2); \ - std r12,32(r1); \ cmpdi r12,0; \ bne- LABEL; \ 1: