From patchwork Fri Apr 26 00:11:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 10918647 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D98951575 for ; Fri, 26 Apr 2019 07:33:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CAA4B28DA2 for ; Fri, 26 Apr 2019 07:33:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BE61228DA4; Fri, 26 Apr 2019 07:33:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=2.0 tests=BAYES_00,DATE_IN_PAST_06_12, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D3FF28DA3 for ; Fri, 26 Apr 2019 07:33:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726246AbfDZHbz (ORCPT ); Fri, 26 Apr 2019 03:31:55 -0400 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:2747 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726197AbfDZHby (ORCPT ); Fri, 26 Apr 2019 03:31:54 -0400 Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Fri, 26 Apr 2019 00:31:40 -0700 Received: from sc2-haas01-esx0118.eng.vmware.com (sc2-haas01-esx0118.eng.vmware.com [10.172.44.118]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 1086741299; Fri, 26 Apr 2019 00:31:46 -0700 (PDT) From: Nadav Amit To: Peter Zijlstra , Borislav Petkov , Andy Lutomirski , Ingo Molnar CC: , , , Thomas Gleixner , Nadav Amit , Dave Hansen , , , , , , , , , , , Rick Edgecombe Subject: [PATCH v5 19/23] x86/ftrace: Use vmalloc special flag Date: Thu, 25 Apr 2019 17:11:39 -0700 Message-ID: <20190426001143.4983-20-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190426001143.4983-1-namit@vmware.com> References: <20190426001143.4983-1-namit@vmware.com> MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-001.vmware.com: namit@vmware.com does not designate permitted sender hosts) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Rick Edgecombe Use new flag VM_FLUSH_RESET_PERMS for handling freeing of special permissioned memory in vmalloc and remove places where memory was set NX and RW before freeing which is no longer needed. Acked-by: Steven Rostedt (VMware) Tested-by: Steven Rostedt (VMware) Signed-off-by: Rick Edgecombe --- arch/x86/kernel/ftrace.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 53ba1aa3a01f..0caf8122d680 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -678,12 +678,8 @@ static inline void *alloc_tramp(unsigned long size) { return module_alloc(size); } -static inline void tramp_free(void *tramp, int size) +static inline void tramp_free(void *tramp) { - int npages = PAGE_ALIGN(size) >> PAGE_SHIFT; - - set_memory_nx((unsigned long)tramp, npages); - set_memory_rw((unsigned long)tramp, npages); module_memfree(tramp); } #else @@ -692,7 +688,7 @@ static inline void *alloc_tramp(unsigned long size) { return NULL; } -static inline void tramp_free(void *tramp, int size) { } +static inline void tramp_free(void *tramp) { } #endif /* Defined as markers to the end of the ftrace default trampolines */ @@ -808,6 +804,8 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) /* ALLOC_TRAMP flags lets us know we created it */ ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP; + set_vm_flush_reset_perms(trampoline); + /* * Module allocation needs to be completed by making the page * executable. The page is still writable, which is a security hazard, @@ -816,7 +814,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) set_memory_x((unsigned long)trampoline, npages); return (unsigned long)trampoline; fail: - tramp_free(trampoline, *tramp_size); + tramp_free(trampoline); return 0; } @@ -947,7 +945,7 @@ void arch_ftrace_trampoline_free(struct ftrace_ops *ops) if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) return; - tramp_free((void *)ops->trampoline, ops->trampoline_size); + tramp_free((void *)ops->trampoline); ops->trampoline = 0; }