Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753811AbbDBOg6 (ORCPT ); Thu, 2 Apr 2015 10:36:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33716 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753674AbbDBOgw (ORCPT ); Thu, 2 Apr 2015 10:36:52 -0400 From: Denys Vlasenko To: Ingo Molnar Cc: Denys Vlasenko , Linus Torvalds , Steven Rostedt , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Oleg Nesterov , Frederic Weisbecker , Alexei Starovoitov , Will Drewry , Kees Cook , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/9] x86/asm/entry/64: reuse stub return code Date: Thu, 2 Apr 2015 16:36:10 +0200 Message-Id: <1427985378-4287-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2778 Lines: 104 Various flavors of stub_{sigreturn,execve}, six functions in total, repeat movq %rax,RAX(%rsp) RESTORE_EXTRA_REGS jmp int_ret_from_sys_call sequence. RESTORE_EXTRA_REGS is six 5-byte insns. Reuse this code. Signed-off-by: Denys Vlasenko CC: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/kernel/entry_64.S | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 13185c5..765436c 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -423,6 +423,7 @@ ENTRY(stub_execve) DEFAULT_FRAME 0 SAVE_EXTRA_REGS call sys_execve +return_from_stub: movq %rax,RAX(%rsp) RESTORE_EXTRA_REGS jmp int_ret_from_sys_call @@ -435,9 +436,7 @@ ENTRY(stub_execveat) DEFAULT_FRAME 0 SAVE_EXTRA_REGS call sys_execveat - movq %rax,RAX(%rsp) - RESTORE_EXTRA_REGS - jmp int_ret_from_sys_call + jmp return_from_stub CFI_ENDPROC END(stub_execveat) @@ -451,9 +450,7 @@ ENTRY(stub_rt_sigreturn) DEFAULT_FRAME 0 SAVE_EXTRA_REGS call sys_rt_sigreturn - movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer - RESTORE_EXTRA_REGS - jmp int_ret_from_sys_call + jmp return_from_stub CFI_ENDPROC END(stub_rt_sigreturn) @@ -464,9 +461,7 @@ ENTRY(stub_x32_rt_sigreturn) DEFAULT_FRAME 0 SAVE_EXTRA_REGS call sys32_x32_rt_sigreturn - movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer - RESTORE_EXTRA_REGS - jmp int_ret_from_sys_call + jmp return_from_stub CFI_ENDPROC END(stub_x32_rt_sigreturn) @@ -476,9 +471,7 @@ ENTRY(stub_x32_execve) DEFAULT_FRAME 0 SAVE_EXTRA_REGS call compat_sys_execve - movq %rax,RAX(%rsp) - RESTORE_EXTRA_REGS - jmp int_ret_from_sys_call + jmp return_from_stub CFI_ENDPROC END(stub_x32_execve) @@ -488,9 +481,7 @@ ENTRY(stub_x32_execveat) DEFAULT_FRAME 0 SAVE_EXTRA_REGS call compat_sys_execveat - movq %rax,RAX(%rsp) - RESTORE_EXTRA_REGS - jmp int_ret_from_sys_call + jmp return_from_stub CFI_ENDPROC END(stub_x32_execveat) -- 1.8.1.4 -- 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/