From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932473AbaBFBM6 (ORCPT ); Wed, 5 Feb 2014 20:12:58 -0500 Received: from mail-pb0-f42.google.com ([209.85.160.42]:38994 "EHLO mail-pb0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932144AbaBFBLB (ORCPT ); Wed, 5 Feb 2014 20:11:01 -0500 From: Alexei Starovoitov To: Ingo Molnar Cc: "David S. Miller" , Steven Rostedt , Peter Zijlstra , "H. Peter Anvin" , Thomas Gleixner , Masami Hiramatsu , Tom Zanussi , Jovi Zhangwei , Eric Dumazet , Linus Torvalds , Andrew Morton , Frederic Weisbecker , Arnaldo Carvalho de Melo , Pekka Enberg , Arjan van de Ven , Christoph Hellwig , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [RFC PATCH v2 tip 4/7] Revert "x86/ptrace: Remove unused regs_get_argument_nth API" Date: Wed, 5 Feb 2014 17:10:43 -0800 Message-Id: <1391649046-4383-5-git-send-email-ast@plumgrid.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1391649046-4383-1-git-send-email-ast@plumgrid.com> References: <1391649046-4383-1-git-send-email-ast@plumgrid.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This reverts commit aa5add93e92019018e905146f8c3d3f8e3c08300. Signed-off-by: Alexei Starovoitov --- arch/x86/include/asm/ptrace.h | 3 +++ arch/x86/kernel/ptrace.c | 24 ++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 14fd6fd..e026176 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -222,6 +222,9 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, return 0; } +/* Get Nth argument at function call */ +unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n); + #define arch_has_single_step() (1) #ifdef CONFIG_X86_DEBUGCTLMSR #define arch_has_block_step() (1) diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 7461f50..ac1c705 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -141,6 +141,30 @@ static const int arg_offs_table[] = { #endif }; +/** + * regs_get_argument_nth() - get Nth argument at function call + * @regs: pt_regs which contains registers at function entry. + * @n: argument number. + * + * regs_get_argument_nth() returns @n th argument of a function call. + * Since usually the kernel stack will be changed right after function entry, + * you must use this at function entry. If the @n th entry is NOT in the + * kernel stack or pt_regs, this returns 0. + */ +unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n) +{ + if (n < ARRAY_SIZE(arg_offs_table)) + return *(unsigned long *)((char *)regs + arg_offs_table[n]); + else { + /* + * The typical case: arg n is on the stack. + * (Note: stack[0] = return address, so skip it) + */ + n -= ARRAY_SIZE(arg_offs_table); + return regs_get_kernel_stack_nth(regs, 1 + n); + } +} + /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. -- 1.7.9.5