From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937855AbdEXBJO (ORCPT ); Tue, 23 May 2017 21:09:14 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35053 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757403AbdEXBJG (ORCPT ); Tue, 23 May 2017 21:09:06 -0400 From: Florian Fainelli To: linux-kernel@vger.kernel.org Cc: elicooper@gmx.com, Florian Fainelli , Jeff Dike , Richard Weinberger , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), user-mode-linux-devel@lists.sourceforge.net (open list:USER-MODE LINUX (UML)), user-mode-linux-user@lists.sourceforge.net (open list:USER-MODE LINUX (UML)) Subject: [PATCH] um: Allow building and running on older hosts Date: Tue, 23 May 2017 18:08:57 -0700 Message-Id: <20170524010858.16134-1-f.fainelli@gmail.com> X-Mailer: git-send-email 2.12.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit a78ff1112263 ("um: add extended processor state save/restore support") and b6024b21fec8 ("um: extend fpstate to _xstate to support YMM registers") forced the use of the x86 FP _xstate and PTRACE_GETREGSET/SETREGSET. On older hosts, we would neither be able to build UML nor run it anymore with these two commits applied because we don't have definitions for struct _xstate nor these two ptrace requests. We can determine at build time which fp context structure to check against, just like we can keep using the old i387 fp save/restore if PTRACE_GETRESET/SETREGSET are not defined. Fixes: a78ff1112263 ("um: add extended processor state save/restore support") Fixes: b6024b21fec8 ("um: extend fpstate to _xstate to support YMM registers") Signed-off-by: Florian Fainelli --- arch/x86/um/os-Linux/registers.c | 13 +++++++++---- arch/x86/um/user-offsets.c | 4 ++++ 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c index 00f54a91bb4b..502bd642e5c2 100644 --- a/arch/x86/um/os-Linux/registers.c +++ b/arch/x86/um/os-Linux/registers.c @@ -26,13 +26,14 @@ int save_i387_registers(int pid, unsigned long *fp_regs) int save_fp_registers(int pid, unsigned long *fp_regs) { - struct iovec iov; - if (have_xstate_support) { +#ifdef PTRACE_GETREGSET + struct iovec iov; iov.iov_base = fp_regs; iov.iov_len = sizeof(struct _xstate); if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) < 0) return -errno; +#endif return 0; } else { return save_i387_registers(pid, fp_regs); @@ -48,13 +49,15 @@ int restore_i387_registers(int pid, unsigned long *fp_regs) int restore_fp_registers(int pid, unsigned long *fp_regs) { - struct iovec iov; - if (have_xstate_support) { +#ifdef PTRACE_SETREGSET + struct iovec iov; + iov.iov_base = fp_regs; iov.iov_len = sizeof(struct _xstate); if (ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov) < 0) return -errno; +#endif return 0; } else { return restore_i387_registers(pid, fp_regs); @@ -127,8 +130,10 @@ void arch_init_registers(int pid) iov.iov_base = &fp_regs; iov.iov_len = sizeof(struct _xstate); +#ifdef PTRACE_GETREGSET if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) == 0) have_xstate_support = 1; +#endif } #endif diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c index cb3c22370cf5..8af0fb5d2780 100644 --- a/arch/x86/um/user-offsets.c +++ b/arch/x86/um/user-offsets.c @@ -50,7 +50,11 @@ void foo(void) DEFINE(HOST_GS, GS); DEFINE(HOST_ORIG_AX, ORIG_EAX); #else +#if defined(PTRACE_GETREGSET) && defined(PTRACE_SETREGSET) DEFINE(HOST_FP_SIZE, sizeof(struct _xstate) / sizeof(unsigned long)); +#else + DEFINE(HOST_FP_SIZE, sizeof(struct _fpstate) / sizeof(unsigned long)); +#endif DEFINE_LONGS(HOST_BX, RBX); DEFINE_LONGS(HOST_CX, RCX); DEFINE_LONGS(HOST_DI, RDI); -- 2.12.2