From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvdis2pqptMSuj+yTks9BvwyUW+cfOHjWAGFlc9Ej8DRCszgZ2DHrJE8Jt/Gw6vXW5cWcAM ARC-Seal: i=1; a=rsa-sha256; t=1521098603; cv=none; d=google.com; s=arc-20160816; b=AZGDfgf/OIaN3sPe3vWnDsxYhmnu2wZEV4nqbyPInly/XaWU03nM/l5EElHSpdB4Le QtxZo/T2+kM6erzajDWBkTUYILIEtcNu9HtS6NJb+H3lCZadxPc6CAnmAmjXf2HeGctU mNnvP4Hjpkm3xJ/eIyCosAKnqZ+CKHRopnQbPTvGgKgWRDv5tgqYLVfPFSpmnjRUGCg0 EH4MwAHHBBjthX9XRgNfNljI4oYkdLrzOmM6gq776Su7gRsvMJa+V4Ajtw9rC+QKSCsq T5h0OmWXraHENa2GQrRkCWYVh0NL+OIrOmw3+Rya18NJvIDJ80WUZO58rMDVcbvIB7tN iIBw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date :dmarc-filter:arc-authentication-results; bh=L7MiktSjfEs6kpMm4CdMIDdVzwnthgMEwoCJhes1xrU=; b=xedNP1rRi9r7H3H9iQEfyMpKklwE9G2enhBGf0zeo9mRB0hewf3IGAXUvbZjGtc4zV O9BifeADNjzt0SZ9NbY69pj+13WT9DQQuFC7bKzwGSEyHqDpvfdO8F2SXKV6hcznJr6D q3KRwb9mM/AvLgmEWMEib1LdFq7tVbD5MwR+phSVkrI5KsoDGyjbWSQyF0+/paJOw6zF ty8E5EdCgcLyJ+1YtI4NjPjBK/mwiV8tkMpxE5bV+B53yf+JUxcQQJT3/W9uX6Bxx3An 7IdvZGzpIZhc07zKr0W9cwIyDoRp2xNWUHNlvSvliUxNqmKGzCRGOj204usya8KMyxqD +Dtg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kselftest-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kselftest-owner@vger.kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kselftest-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kselftest-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751289AbeCOHXJ (ORCPT ); Thu, 15 Mar 2018 03:23:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:52026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751765AbeCOHXH (ORCPT ); Thu, 15 Mar 2018 03:23:07 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBE3620779 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mhiramat@kernel.org Date: Thu, 15 Mar 2018 16:23:03 +0900 From: Masami Hiramatsu To: Masami Hiramatsu Cc: Ravi Bangoria , Steven Rostedt , linux-kernel@vger.kernel.org, Ingo Molnar , Namhyung Kim , Tom Zanussi , Arnaldo Carvalho de Melo , linux-trace-users@vger.kernel.org, linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: Re: [PATCH v5 16/19] tracing: probeevent: Add array type support Message-Id: <20180315162303.1250dea1500aea420ecd85c6@kernel.org> In-Reply-To: <20180315161840.71d524a73307881febfe34c2@kernel.org> References: <152049860385.7289.14079393589900496424.stgit@devbox> <152049905133.7289.17516121776689315422.stgit@devbox> <72be81a4-710a-b942-277d-9156c3debc5d@linux.vnet.ibm.com> <20180315161840.71d524a73307881febfe34c2@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kselftest-owner@vger.kernel.org X-Mailing-List: linux-kselftest@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594358839822578667?= X-GMAIL-MSGID: =?utf-8?q?1594987489069655970?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Hi Ravi, On Thu, 15 Mar 2018 16:18:40 +0900 Masami Hiramatsu wrote: > On Thu, 15 Mar 2018 11:18:19 +0530 > Ravi Bangoria wrote: > > > Hi Masami, > > > > On 03/08/2018 02:20 PM, Masami Hiramatsu wrote: > > > Add array type support for probe events. > > > This allows user to get arraied types from memory address. > > > The array type syntax is > > > > > > TYPE[N] > > > > > > Where TYPE is one of types (u8/16/32/64,s8/16/32/64, > > > x8/16/32/64, symbol, string) and N is a fixed value less > > > than 64. > > > > > > The string array type is a bit different from other types. For > > > other base types, [1] is equal to > > > (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not > > > equal to string. The string type itself represents "char array", > > > but string array type represents "char * array". So, for example, > > > +0(%di):string[1] is equal to +0(+0(%di)):string. > > > > I was trying to test this patch. But I'm not getting proper data. > > Here is what I'm doing... > > > > $ cat hello.c > > #include > > > > void foo1(int a[]) > > { > >     printf("%d\n", a[2]); > > } > > > > void foo(int a[]) > > { > >     printf("%d\n", a[1]); > >     foo1(a); > > } > > > > void main() > > { > >     int a[3] = {4, 5, 6}; > >     printf("%d\n", a[0]); > >     foo(a); > > } > > > > $ gcc -g hello.c -o hello > > $ sudo ./perf probe -x ~/hello foo1 'a=a:x32[3]' > > $ sudo cat /sys/kernel/debug/tracing/uprobe_events > > p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+96(%gpr31):x32[3] > > > > $ sudo ./perf record -e probe_hello:foo1 ~/hello > > $ sudo ./perf script > > hello  6913 [038]  2857.704470: probe_hello:foo1: (100005fc) a={0xd69e4400,0x7fff,0x0} > > > > > > I don't see proper values of the 'a'? Anything wrong with my perf commands :) ? > > Ah, I guess since it is a pointer. in main() function, "a" is an array, > but in foo1(), "a" is a pointer to the array. > From the viewpoint of C source code, both pointer and array is same > expression, but actually it is not same from memory point of view. > perf probe has to be updated to enable it too. > > Could you please try to do as below? > > $ echo "p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+0(+96(%gpr31)):x32[3]" | sudo tee /sys/kernel/debug/tracing/uprobe_events Sorry, that is too complicated than enough. you should try to specify a[0] instead of a. $ sudo ./perf probe -x ~/hello foo1 'a=a[0]:x32[3]' :) Thank you, -- Masami Hiramatsu From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhiramat at kernel.org (Masami Hiramatsu) Date: Thu, 15 Mar 2018 16:23:03 +0900 Subject: [PATCH v5 16/19] tracing: probeevent: Add array type support In-Reply-To: <20180315161840.71d524a73307881febfe34c2@kernel.org> References: <152049860385.7289.14079393589900496424.stgit@devbox> <152049905133.7289.17516121776689315422.stgit@devbox> <72be81a4-710a-b942-277d-9156c3debc5d@linux.vnet.ibm.com> <20180315161840.71d524a73307881febfe34c2@kernel.org> Message-ID: <20180315162303.1250dea1500aea420ecd85c6@kernel.org> Hi Ravi, On Thu, 15 Mar 2018 16:18:40 +0900 Masami Hiramatsu wrote: > On Thu, 15 Mar 2018 11:18:19 +0530 > Ravi Bangoria wrote: > > > Hi Masami, > > > > On 03/08/2018 02:20 PM, Masami Hiramatsu wrote: > > > Add array type support for probe events. > > > This allows user to get arraied types from memory address. > > > The array type syntax is > > > > > > TYPE[N] > > > > > > Where TYPE is one of types (u8/16/32/64,s8/16/32/64, > > > x8/16/32/64, symbol, string) and N is a fixed value less > > > than 64. > > > > > > The string array type is a bit different from other types. For > > > other base types, [1] is equal to > > > (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not > > > equal to string. The string type itself represents "char array", > > > but string array type represents "char * array". So, for example, > > > +0(%di):string[1] is equal to +0(+0(%di)):string. > > > > I was trying to test this patch. But I'm not getting proper data. > > Here is what I'm doing... > > > > $ cat hello.c > > #include > > > > void foo1(int a[]) > > { > >     printf("%d\n", a[2]); > > } > > > > void foo(int a[]) > > { > >     printf("%d\n", a[1]); > >     foo1(a); > > } > > > > void main() > > { > >     int a[3] = {4, 5, 6}; > >     printf("%d\n", a[0]); > >     foo(a); > > } > > > > $ gcc -g hello.c -o hello > > $ sudo ./perf probe -x ~/hello foo1 'a=a:x32[3]' > > $ sudo cat /sys/kernel/debug/tracing/uprobe_events > > p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+96(%gpr31):x32[3] > > > > $ sudo ./perf record -e probe_hello:foo1 ~/hello > > $ sudo ./perf script > > hello  6913 [038]  2857.704470: probe_hello:foo1: (100005fc) a={0xd69e4400,0x7fff,0x0} > > > > > > I don't see proper values of the 'a'? Anything wrong with my perf commands :) ? > > Ah, I guess since it is a pointer. in main() function, "a" is an array, > but in foo1(), "a" is a pointer to the array. > From the viewpoint of C source code, both pointer and array is same > expression, but actually it is not same from memory point of view. > perf probe has to be updated to enable it too. > > Could you please try to do as below? > > $ echo "p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+0(+96(%gpr31)):x32[3]" | sudo tee /sys/kernel/debug/tracing/uprobe_events Sorry, that is too complicated than enough. you should try to specify a[0] instead of a. $ sudo ./perf probe -x ~/hello foo1 'a=a[0]:x32[3]' :) Thank you, -- Masami Hiramatsu -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhiramat@kernel.org (Masami Hiramatsu) Date: Thu, 15 Mar 2018 16:23:03 +0900 Subject: [PATCH v5 16/19] tracing: probeevent: Add array type support In-Reply-To: <20180315161840.71d524a73307881febfe34c2@kernel.org> References: <152049860385.7289.14079393589900496424.stgit@devbox> <152049905133.7289.17516121776689315422.stgit@devbox> <72be81a4-710a-b942-277d-9156c3debc5d@linux.vnet.ibm.com> <20180315161840.71d524a73307881febfe34c2@kernel.org> Message-ID: <20180315162303.1250dea1500aea420ecd85c6@kernel.org> Content-Type: text/plain; charset="UTF-8" Message-ID: <20180315072303.MXpk0ZOb2Odi_VdZ5nUJntjslbwyF8MuMeZAnAkH8a0@z> Hi Ravi, On Thu, 15 Mar 2018 16:18:40 +0900 Masami Hiramatsu wrote: > On Thu, 15 Mar 2018 11:18:19 +0530 > Ravi Bangoria wrote: > > > Hi Masami, > > > > On 03/08/2018 02:20 PM, Masami Hiramatsu wrote: > > > Add array type support for probe events. > > > This allows user to get arraied types from memory address. > > > The array type syntax is > > > > > > TYPE[N] > > > > > > Where TYPE is one of types (u8/16/32/64,s8/16/32/64, > > > x8/16/32/64, symbol, string) and N is a fixed value less > > > than 64. > > > > > > The string array type is a bit different from other types. For > > > other base types, [1] is equal to > > > (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not > > > equal to string. The string type itself represents "char array", > > > but string array type represents "char * array". So, for example, > > > +0(%di):string[1] is equal to +0(+0(%di)):string. > > > > I was trying to test this patch. But I'm not getting proper data. > > Here is what I'm doing... > > > > $ cat hello.c > > #include > > > > void foo1(int a[]) > > { > >     printf("%d\n", a[2]); > > } > > > > void foo(int a[]) > > { > >     printf("%d\n", a[1]); > >     foo1(a); > > } > > > > void main() > > { > >     int a[3] = {4, 5, 6}; > >     printf("%d\n", a[0]); > >     foo(a); > > } > > > > $ gcc -g hello.c -o hello > > $ sudo ./perf probe -x ~/hello foo1 'a=a:x32[3]' > > $ sudo cat /sys/kernel/debug/tracing/uprobe_events > > p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+96(%gpr31):x32[3] > > > > $ sudo ./perf record -e probe_hello:foo1 ~/hello > > $ sudo ./perf script > > hello  6913 [038]  2857.704470: probe_hello:foo1: (100005fc) a={0xd69e4400,0x7fff,0x0} > > > > > > I don't see proper values of the 'a'? Anything wrong with my perf commands :) ? > > Ah, I guess since it is a pointer. in main() function, "a" is an array, > but in foo1(), "a" is a pointer to the array. > From the viewpoint of C source code, both pointer and array is same > expression, but actually it is not same from memory point of view. > perf probe has to be updated to enable it too. > > Could you please try to do as below? > > $ echo "p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+0(+96(%gpr31)):x32[3]" | sudo tee /sys/kernel/debug/tracing/uprobe_events Sorry, that is too complicated than enough. you should try to specify a[0] instead of a. $ sudo ./perf probe -x ~/hello foo1 'a=a[0]:x32[3]' :) Thank you, -- Masami Hiramatsu -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html