From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1HTPMW-0004pb-H0 for user-mode-linux-devel@lists.sourceforge.net; Mon, 19 Mar 2007 14:25:52 -0700 Received: from ns2.suse.de ([195.135.220.15] helo=mx2.suse.de) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1HTPMV-0007lG-8B for user-mode-linux-devel@lists.sourceforge.net; Mon, 19 Mar 2007 14:25:52 -0700 From: Date: Mon, 19 Mar 2007 14:23:49 -0700 In-Reply-To: <20070319201250.GC12179@c2.user-mode-linux.org> Message-Id: <20070319212538.1262DCB18F7@imap.suse.de> Subject: [uml-devel] patch uml-arch_prctl-should-set-thread-fs.patch queued to -stable tree List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: jdike@addtoit.com, greg@kroah.com, gregkh@suse.de, user-mode-linux-devel@lists.sourceforge.net Cc: stable@kernel.org This is a note to let you know that we have just queued up the patch titled Subject: UML - arch_prctl should set thread fs to the 2.6.20-stable tree. Its filename is uml-arch_prctl-should-set-thread-fs.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >From jdike@addtoit.com Mon Mar 19 13:16:13 2007 From: Jeff Dike Date: Mon, 19 Mar 2007 16:12:50 -0400 Subject: UML - arch_prctl should set thread fs To: stable@kernel.org Cc: Greg KH , uml-devel Message-ID: <20070319201250.GC12179@c2.user-mode-linux.org> From: Jeff Dike x86_64 needs some TLS fixes. What was missing was remembering the child thread id during clone and stuffing it into the child during each context switch. The %fs value is stored separately in the thread structure since the host controls what effect it has on the actual register file. The host also needs to store it in its own thread struct, so we need the value kept outside the register file. arch_prctl_skas was fixed to call PTRACE_ARCH_PRCTL appropriately. There is some saving and restoring of registers in the ARCH_SET_* cases so that the correct set of registers are changed on the host and restored to the process when it runs again. Signed-off-by: Jeff Dike Signed-off-by: Greg Kroah-Hartman --- linux-2.6.20.3.orig/arch/um/include/os.h +++ linux-2.6.20.3/arch/um/include/os.h @@ -341,4 +341,6 @@ extern void maybe_sigio_broken(int fd, i extern void sig_handler_common_skas(int sig, void *sc_ptr); extern void user_signal(int sig, union uml_pt_regs *regs, int pid); +extern int os_arch_prctl(int pid, int code, unsigned long *addr); + #endif Index: linux-2.6.20.3/arch/um/os-Linux/sys-x86_64/Makefile =================================================================== --- linux-2.6.20.3.orig/arch/um/os-Linux/sys-x86_64/Makefile +++ linux-2.6.20.3/arch/um/os-Linux/sys-x86_64/Makefile @@ -3,7 +3,7 @@ # Licensed under the GPL # -obj-$(CONFIG_MODE_SKAS) = registers.o signal.o +obj-$(CONFIG_MODE_SKAS) = registers.o prctl.o signal.o USER_OBJS := $(obj-y) Index: linux-2.6.20.3/arch/um/os-Linux/sys-x86_64/prctl.c =================================================================== --- /dev/null +++ linux-2.6.20.3/arch/um/os-Linux/sys-x86_64/prctl.c @@ -0,0 +1,12 @@ +/* + * Copyright (C) 2007 Jeff Dike (jdike@{addtoit.com,linux.intel.com}) + * Licensed under the GPL + */ + +#include +#include + +int os_arch_prctl(int pid, int code, unsigned long *addr) +{ + return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) addr, code); +} Index: linux-2.6.20.3/arch/um/sys-x86_64/syscalls.c =================================================================== --- linux-2.6.20.3.orig/arch/um/sys-x86_64/syscalls.c +++ linux-2.6.20.3/arch/um/sys-x86_64/syscalls.c @@ -16,6 +16,7 @@ #include "asm/prctl.h" /* XXX This should get the constants from libc */ #include "choose-mode.h" #include "kern.h" +#include "os.h" asmlinkage long sys_uname64(struct new_utsname __user * name) { @@ -58,40 +59,70 @@ static long arch_prctl_tt(int code, unsi #ifdef CONFIG_MODE_SKAS -/* XXX: Must also call arch_prctl in the host, beside saving the segment bases! */ -static long arch_prctl_skas(int code, unsigned long addr) +static long arch_prctl_skas(int code, unsigned long __user *addr) { - long ret = 0; + unsigned long *ptr = addr, tmp; + long ret; + int pid = current->mm->context.skas.id.u.pid; + + /* + * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to + * be safe), we need to call arch_prctl on the host because + * setting %fs may result in something else happening (like a + * GDT being set instead). So, we let the host fiddle the + * registers and restore them afterwards. + * + * So, the saved registers are stored to the process (this + * needed because a stub may have been the last thing to run), + * arch_prctl is run on the host, then the registers are read + * back. + */ + switch(code){ + case ARCH_SET_FS: + case ARCH_SET_GS: + restore_registers(pid, ¤t->thread.regs.regs); + break; + case ARCH_GET_FS: + case ARCH_GET_GS: + /* + * With these two, we read to a local pointer and + * put_user it to the userspace pointer that we were + * given. If addr isn't valid (because it hasn't been + * faulted in or is just bogus), we want put_user to + * fault it in (or return -EFAULT) instead of having + * the host return -EFAULT. + */ + ptr = &tmp; + } + + ret = os_arch_prctl(pid, code, ptr); + if(ret) + return ret; switch(code){ case ARCH_SET_FS: - current->thread.regs.regs.skas.regs[FS_BASE / sizeof(unsigned long)] = addr; + current->thread.arch.fs = (unsigned long) ptr; + save_registers(pid, ¤t->thread.regs.regs); break; case ARCH_SET_GS: - current->thread.regs.regs.skas.regs[GS_BASE / sizeof(unsigned long)] = addr; + save_registers(pid, ¤t->thread.regs.regs); break; case ARCH_GET_FS: - ret = put_user(current->thread.regs.regs.skas. - regs[FS_BASE / sizeof(unsigned long)], - (unsigned long __user *)addr); - break; + ret = put_user(tmp, addr); + break; case ARCH_GET_GS: - ret = put_user(current->thread.regs.regs.skas. - regs[GS_BASE / sizeof(unsigned long)], - (unsigned long __user *)addr); - break; - default: - ret = -EINVAL; + ret = put_user(tmp, addr); break; } - return(ret); + return ret; } #endif long sys_arch_prctl(int code, unsigned long addr) { - return(CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code, addr)); + return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code, + (unsigned long __user *) addr); } long sys_clone(unsigned long clone_flags, unsigned long newsp, @@ -105,5 +136,14 @@ long sys_clone(unsigned long clone_flags ret = do_fork(clone_flags, newsp, ¤t->thread.regs, 0, parent_tid, child_tid); current->thread.forking = 0; - return(ret); + return ret; } + +void arch_switch_to_skas(struct task_struct *from, struct task_struct *to) +{ + if((to->thread.arch.fs == 0) || (to->mm == NULL)) + return; + + arch_prctl_skas(ARCH_SET_FS, (void __user *) to->thread.arch.fs); +} + Index: linux-2.6.20.3/arch/um/sys-x86_64/tls.c =================================================================== --- linux-2.6.20.3.orig/arch/um/sys-x86_64/tls.c +++ linux-2.6.20.3/arch/um/sys-x86_64/tls.c @@ -1,14 +1,17 @@ #include "linux/sched.h" -void debug_arch_force_load_TLS(void) -{ -} - void clear_flushed_tls(struct task_struct *task) { } int arch_copy_tls(struct task_struct *t) { + /* + * If CLONE_SETTLS is set, we need to save the thread id + * (which is argument 5, child_tid, of clone) so it can be set + * during context switches. + */ + t->thread.arch.fs = t->thread.regs.regs.skas.regs[R8 / sizeof(long)]; + return 0; } Index: linux-2.6.20.3/include/asm-um/processor-x86_64.h =================================================================== --- linux-2.6.20.3.orig/include/asm-um/processor-x86_64.h +++ linux-2.6.20.3/include/asm-um/processor-x86_64.h @@ -13,6 +13,7 @@ struct arch_thread { unsigned long debugregs[8]; int debugregs_seq; + unsigned long fs; struct faultinfo faultinfo; }; @@ -25,8 +26,9 @@ extern inline void rep_nop(void) #define cpu_relax() rep_nop() #define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \ - .debugregs_seq = 0, \ - .faultinfo = { 0, 0, 0 } } + .debugregs_seq = 0, \ + .fs = 0, \ + .faultinfo = { 0, 0, 0 } } static inline void arch_flush_thread(struct arch_thread *thread) { Index: linux-2.6.20.3/include/asm-um/ptrace-x86_64.h =================================================================== --- linux-2.6.20.3.orig/include/asm-um/ptrace-x86_64.h +++ linux-2.6.20.3/include/asm-um/ptrace-x86_64.h @@ -81,9 +81,7 @@ static inline void arch_switch_to_tt(str { } -static inline void arch_switch_to_skas(struct task_struct *from, - struct task_struct *to) -{ -} +extern void arch_switch_to_skas(struct task_struct *from, + struct task_struct *to); #endif Patches currently in stable-queue which might be from jdike@addtoit.com are ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel