Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756373AbZKIPdp (ORCPT ); Mon, 9 Nov 2009 10:33:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756370AbZKIPdo (ORCPT ); Mon, 9 Nov 2009 10:33:44 -0500 Received: from mail-ew0-f207.google.com ([209.85.219.207]:39623 "EHLO mail-ew0-f207.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756365AbZKIPdm (ORCPT ); Mon, 9 Nov 2009 10:33:42 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=QzwBJA+T/+vn7qQa69Utlt9GnLHbsuWQ2AHEIHEzr23Ci8hWF8AiG/mfouQj1Nv8Pg BT3lWyT+Lof7dX9XPLGtzJOlZGipiJGzitiXYQOp2thfygoMzsmA8jsFn0cU5k2QCmdC /T7iXzjCzPEfnrJuGou2KhswV/mLLpH4kBQCM= From: Wu Zhangjin To: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org Cc: zhangfx@lemote.com, zhouqg@gmail.com, Wu Zhangjin , Ralf Baechle , rostedt@goodmis.org, Frederic Weisbecker , Ingo Molnar , Nicholas Mc Guire , David Daney , Richard Sandiford , Patrik Kluba , Thomas Gleixner , Michal Simek Subject: [PATCH v7 16/17] tracing: reserve $12(t0) for mcount-ra-address of gcc 4.5 Date: Mon, 9 Nov 2009 23:31:33 +0800 Message-Id: X-Mailer: git-send-email 1.6.2.1 In-Reply-To: <406a8e5e3117737e401bb2bba84ad9b17f99857d.1257779502.git.wuzhangjin@gmail.com> References: <9dc81a7a9e5a292cccdf465c533a2b08d19d6021.1257779502.git.wuzhangjin@gmail.com> <8f579e2cece16cd22358a4ec143ef6a8c462639b.1257779502.git.wuzhangjin@gmail.com> <6199d7b3956b544fc65896af1062787a2e1283ce.1257779502.git.wuzhangjin@gmail.com> <58a7558730fbea6cd0417100c8fcd6f45668d1e3.1257779502.git.wuzhangjin@gmail.com> <3a9fc9ca02e8e6e9c3c28797a4c084c1f9d91f69.1257779502.git.wuzhangjin@gmail.com> <0cef783a71333ff96a78aaea8961e3b6b5392665.1257779502.git.wuzhangjin@gmail.com> <18e1d617ed824bb1c10f15216f2ed9ed3de78abd.1257779502.git.wuzhangjin@gmail.com> <3da916c1cb6e05445438826f98a91111f43ff6cd.1257779502.git.wuzhangjin@gmail.com> <451c55dead5d6afd871de6afd14dbbcf70a0f834.1257779502.git.wuzhangjin@gmail.com> <0c463e2af521e613fd15751a9f610c74cf887292.1257779502.git.wuzhangjin@gmail.com> <695747bff7cddb97d6f43c05c4cf05eb269e402d.1257779502.git.wuzhangjin@gmail.com> <406a8e5e3117737e401bb2bba84ad9b17f99857d.1257779502.git.wuzhangjin@gmail.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2420 Lines: 79 From: Wu Zhangjin A new option -mmcount-ra-address for gcc 4.5 have been sent by David Daney in the thread "MIPS: Add option to pass return address location to _mcount", which help to record the location of the return address(ra) for the function graph tracer of MIPS to hijack the return address easier and safer. that option used the $12(t0) register by default, so, we reserve it for it, and use t1,t2,t3 instead of t0,t1,t2. Signed-off-by: Wu Zhangjin --- arch/mips/kernel/mcount.S | 26 +++++++++++++------------- 1 files changed, 13 insertions(+), 13 deletions(-) diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index bdfef2c..522e91c 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -65,8 +65,8 @@ NESTED(ftrace_caller, PT_SIZE, ra) _mcount: b ftrace_stub nop - lw t0, function_trace_stop - bnez t0, ftrace_stub + lw t1, function_trace_stop + bnez t1, ftrace_stub nop MCOUNT_SAVE_REGS @@ -93,21 +93,21 @@ ftrace_stub: #else /* ! CONFIG_DYNAMIC_FTRACE */ NESTED(_mcount, PT_SIZE, ra) - lw t0, function_trace_stop - bnez t0, ftrace_stub + lw t1, function_trace_stop + bnez t1, ftrace_stub nop - PTR_LA t0, ftrace_stub - PTR_L t1, ftrace_trace_function /* Prepare t1 for (1) */ - bne t0, t1, static_trace + PTR_LA t1, ftrace_stub + PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */ + bne t1, t2, static_trace nop #ifdef CONFIG_FUNCTION_GRAPH_TRACER - PTR_L t2, ftrace_graph_return - bne t0, t2, ftrace_graph_caller + PTR_L t3, ftrace_graph_return + bne t1, t3, ftrace_graph_caller nop - PTR_LA t0, ftrace_graph_entry_stub - PTR_L t2, ftrace_graph_entry - bne t0, t2, ftrace_graph_caller + PTR_LA t1, ftrace_graph_entry_stub + PTR_L t3, ftrace_graph_entry + bne t1, t3, ftrace_graph_caller nop #endif b ftrace_stub @@ -117,7 +117,7 @@ static_trace: MCOUNT_SAVE_REGS move a0, ra /* arg1: next ip, selfaddr */ - jalr t1 /* (1) call *ftrace_trace_function */ + jalr t2 /* (1) call *ftrace_trace_function */ move a1, AT /* arg2: the caller's next ip, parent */ MCOUNT_RESTORE_REGS -- 1.6.2.1 -- 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/