Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752656AbaAPM05 (ORCPT ); Thu, 16 Jan 2014 07:26:57 -0500 Received: from mail-ve0-f173.google.com ([209.85.128.173]:52248 "EHLO mail-ve0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752093AbaAPM0y (ORCPT ); Thu, 16 Jan 2014 07:26:54 -0500 MIME-Version: 1.0 In-Reply-To: <20140116115634.GE30257@mudshark.cambridge.arm.com> References: <1389869123-5884-1-git-send-email-jean.pihet@linaro.org> <20140116115634.GE30257@mudshark.cambridge.arm.com> Date: Thu, 16 Jan 2014 13:26:53 +0100 Message-ID: Subject: Re: [PATCH] ARM64: perf: support dwarf unwinding in compat mode From: Jean Pihet To: Will Deacon Cc: "linux-kernel@vger.kernel.org" , "linaro-kernel@lists.linaro.org" , "linux-arm-kernel@lists.infradead.org" , Arnaldo , "patches@linaro.org" , Jiri Olsa , Ingo Molnar Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16 January 2014 12:56, Will Deacon wrote: > Hi Jean, > > On Thu, Jan 16, 2014 at 10:45:23AM +0000, Jean Pihet wrote: >> Add support for unwinding using the dwarf information in compat >> mode. Using the correct user stack pointer allows perf to record >> the frames correctly in the native and compat modes. >> >> Note that although the dwarf frame unwinding works ok using >> libunwind in native mode (on ARMv7 & ARMv8), some changes are >> required to the libunwind code for the compat mode. Those changes >> are posted separately on the libunwind mailing list. >> >> Tested on ARMv8 platform with v8 and compat v7 binaries, the latter >> are statically built. > > I guess it makes sense to include this with your earlier series adding > support for compat backtracing? > >> Signed-off-by: Jean Pihet >> --- >> arch/arm64/include/asm/ptrace.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h >> index fbb0020..86d5b54 100644 >> --- a/arch/arm64/include/asm/ptrace.h >> +++ b/arch/arm64/include/asm/ptrace.h >> @@ -133,7 +133,7 @@ struct pt_regs { >> (!((regs)->pstate & PSR_F_BIT)) >> >> #define user_stack_pointer(regs) \ >> - ((regs)->sp) >> + (!compat_user_mode(regs)) ? ((regs)->sp) : ((regs)->compat_sp) > > In your previous series, compat backtracing is actually split out into a > separate function (compat_user_backtrace), so it would be more consistent to > have a compat_user_stack_pointer macro, rather than add this check here. Do you mean this change instead? diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 569b2187..9b88d2e 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -185,7 +185,8 @@ static inline bool arch_perf_have_user_stack_dump(void) return true; } -#define perf_user_stack_pointer(regs) user_stack_pointer(regs) +#define perf_user_stack_pointer(regs) \ + (!compat_user_mode(regs)) ? ((regs)->sp) : ((regs)->compat_sp) #else static inline bool arch_perf_have_user_stack_dump(void) { If so let me prepare/test and re-submit this. Thx! Jean > > 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/