Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753766AbcKQJlN (ORCPT ); Thu, 17 Nov 2016 04:41:13 -0500 Received: from mail-pg0-f65.google.com ([74.125.83.65]:34400 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750841AbcKQJlH (ORCPT ); Thu, 17 Nov 2016 04:41:07 -0500 From: Boqun Feng To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Boqun Feng , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Andrew Donnellan , Christophe Leroy , "Aneesh Kumar K.V" , Rashmica Gupta , Douglas Miller Subject: [RFC] powerpc: xmon: Add address lookup for percpu symbols Date: Thu, 17 Nov 2016 17:40:35 +0800 Message-Id: <20161117094051.21606-1-boqun.feng@gmail.com> X-Mailer: git-send-email 2.10.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1960 Lines: 69 Currently, in xmon, there is no obvious way to get an address for a percpu symbol for a particular cpu. Having such an ability would be good for debugging the system when percpu variables got involved. Therefore, this patch introduces a new xmon command "lp" to lookup the address for percpu symbols. Usage of "lp" is similar to "ls", except that we could add a cpu number to choose the variable of which cpu we want to lookup. If no cpu number is given, lookup for current cpu. Signed-off-by: Boqun Feng --- arch/powerpc/xmon/xmon.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 760545519a0b..3556966a29a5 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -229,6 +229,7 @@ Commands:\n\ f flush cache\n\ la lookup symbol+offset of specified address\n\ ls lookup address of specified symbol\n\ + lp s [#] lookup address of percpu symbol s for current cpu, or cpu #\n\ m examine/change memory\n\ mm move a block of memory\n\ ms set a block of memory\n\ @@ -2943,7 +2944,7 @@ static void symbol_lookup(void) { int type = inchar(); - unsigned long addr; + unsigned long addr, cpu, offset; static char tmp[64]; switch (type) { @@ -2967,6 +2968,31 @@ symbol_lookup(void) catch_memory_errors = 0; termch = 0; break; + case 'p': + getstring(tmp, 64); + if (setjmp(bus_error_jmp) == 0) { + catch_memory_errors = 1; + sync(); + addr = kallsyms_lookup_name(tmp); + sync(); + } + + if (scanhex(&cpu) && cpu < num_possible_cpus()) + offset = per_cpu_offset(cpu); + else { + offset = my_cpu_offset; + cpu = raw_smp_processor_id(); + } + + if (addr) + printf("%s for cpu 0x%lx: %lx\n", tmp, cpu, + addr + offset); + else + printf("Percpu symbol '%s' not found.\n", tmp); + + catch_memory_errors = 0; + termch = 0; + break; } } -- 2.10.1