Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753975Ab2FKNUw (ORCPT ); Mon, 11 Jun 2012 09:20:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49294 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751381Ab2FKNUt (ORCPT ); Mon, 11 Jun 2012 09:20:49 -0400 From: Jiri Olsa To: acme@redhat.com, a.p.zijlstra@chello.nl, mingo@elte.hu, paulus@samba.org, cjashfor@linux.vnet.ibm.com, fweisbec@gmail.com Cc: eranian@google.com, gorcunov@openvz.org, tzanussi@gmail.com, mhiramat@redhat.com, robert.richter@amd.com, fche@redhat.com, linux-kernel@vger.kernel.org, masami.hiramatsu.pt@hitachi.com, drepper@gmail.com, asharma@fb.com, benjamin.redelings@nescent.org, Jiri Olsa Subject: [PATCH 03/19] perf, x86: Add copy_from_user_nmi_nochk for best effort copy Date: Mon, 11 Jun 2012 15:19:58 +0200 Message-Id: <1339420814-7379-4-git-send-email-jolsa@redhat.com> In-Reply-To: <1339420814-7379-1-git-send-email-jolsa@redhat.com> References: <1339420814-7379-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2386 Lines: 71 Adding copy_from_user_nmi_nochk that provides the best effort copy regardless the size crossing the task boundary at the moment. This is going to be useful for stack dump we need in post DWARF CFI based unwind. Signed-off-by: Jiri Olsa --- arch/x86/include/asm/uaccess.h | 2 ++ arch/x86/lib/usercopy.c | 15 +++++++++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index e1f3a17..d8d6bcd 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -562,6 +562,8 @@ struct __large_struct { unsigned long buf[100]; }; #endif /* CONFIG_X86_WP_WORKS_OK */ extern unsigned long +copy_from_user_nmi_nochk(void *to, const void __user *from, unsigned long n); +extern unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n); extern __must_check long strncpy_from_user(char *dst, const char __user *src, long count); diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 677b1ed..29ca1c7 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -14,7 +14,7 @@ * best effort, GUP based copy_from_user() that is NMI-safe */ unsigned long -copy_from_user_nmi(void *to, const void __user *from, unsigned long n) +copy_from_user_nmi_nochk(void *to, const void __user *from, unsigned long n) { unsigned long offset, addr = (unsigned long)from; unsigned long size, len = 0; @@ -22,9 +22,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) void *map; int ret; - if (__range_not_ok(from, n, TASK_SIZE) == 0) - return len; - do { ret = __get_user_pages_fast(addr, 1, 0, &page); if (!ret) @@ -46,4 +43,14 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) return len; } +EXPORT_SYMBOL_GPL(copy_from_user_nmi_nochk); + +unsigned long +copy_from_user_nmi(void *to, const void __user *from, unsigned long n) +{ + if (__range_not_ok(from, n, TASK_SIZE) == 0) + return 0; + + return copy_from_user_nmi_nochk(to, from, n); +} EXPORT_SYMBOL_GPL(copy_from_user_nmi); -- 1.7.7.6 -- 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/