Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754240Ab3JYNP0 (ORCPT ); Fri, 25 Oct 2013 09:15:26 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:48877 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751548Ab3JYNPZ (ORCPT ); Fri, 25 Oct 2013 09:15:25 -0400 Date: Fri, 25 Oct 2013 14:14:41 +0100 From: Will Deacon To: Jean Pihet Cc: Jiri Olsa , Arnaldo , "linux-kernel@vger.kernel.org" , "linaro-kernel@lists.linaro.org" , "linux-arm-kernel@lists.infradead.org" , "patches@linaro.org" , Jean Pihet Subject: Re: [PATCH 1/2] ARM64: perf: add support for perf registers API Message-ID: <20131025131441.GC9999@mudshark.cambridge.arm.com> References: <1382108078-8807-1-git-send-email-jean.pihet@linaro.org> <1382108078-8807-2-git-send-email-jean.pihet@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1382108078-8807-2-git-send-email-jean.pihet@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1782 Lines: 64 On Fri, Oct 18, 2013 at 03:54:37PM +0100, Jean Pihet wrote: > From: Jean Pihet > > This patch implements the functions required for the perf registers API, > allowing the perf tool to interface kernel register dumps with libunwind > in order to provide userspace backtracing. > Only the general purpose user space registers are exported, i.e.: > PERF_REG_ARM_X0, > ... > PERF_REG_ARM_X28, > PERF_REG_ARM_FP, > PERF_REG_ARM_LR, > PERF_REG_ARM_SP, > PERF_REG_ARM_PC > and not the PERF_REG_ARM_V* registers. [...] > diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c > new file mode 100644 > index 0000000..bbcf63c > --- /dev/null > +++ b/arch/arm64/kernel/perf_regs.c > @@ -0,0 +1,29 @@ > +#include > +#include > +#include > +#include > +#include > +#include > + > +u64 perf_reg_value(struct pt_regs *regs, int idx) > +{ > + if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM_MAX)) > + return 0; > + > + return regs->regs[idx]; > +} > + > +#define REG_RESERVED (~((1ULL << PERF_REG_ARM_MAX) - 1)) > + > +int perf_reg_validate(u64 mask) > +{ > + if (!mask || mask & REG_RESERVED) > + return -EINVAL; > + > + return 0; > +} > + > +u64 perf_reg_abi(struct task_struct *task) > +{ > + return PERF_SAMPLE_REGS_ABI_64; > +} You need to deal with compat (AArch32) tasks here too, which means providing something compatible with what we do on arch/arm/ depending on the thread flags. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/