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author | Al Viro <viro@ftp.linux.org.uk> | 2011-08-18 21:06:39 +0200 |
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committer | Richard Weinberger <richard@nod.at> | 2011-11-02 14:15:05 +0100 |
commit | 5c48b108ecbf6505d929e64d50dace13ac2bdf34 (patch) | |
tree | 016904f84fbe05aa301c5cdfe712d90f6bb828fe /arch/x86/um/syscalls_64.c | |
parent | um: merge Makefile-{i386,x86_64} (diff) | |
download | linux-5c48b108ecbf6505d929e64d50dace13ac2bdf34.tar.xz linux-5c48b108ecbf6505d929e64d50dace13ac2bdf34.zip |
um: take arch/um/sys-x86 to arch/x86/um
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/x86/um/syscalls_64.c')
-rw-r--r-- | arch/x86/um/syscalls_64.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c new file mode 100644 index 000000000000..f3d82bb6e15a --- /dev/null +++ b/arch/x86/um/syscalls_64.c @@ -0,0 +1,102 @@ +/* + * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Copyright 2003 PathScale, Inc. + * + * Licensed under the GPL + */ + +#include "linux/linkage.h" +#include "linux/personality.h" +#include "linux/utsname.h" +#include "asm/prctl.h" /* XXX This should get the constants from libc */ +#include "asm/uaccess.h" +#include "os.h" + +long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr) +{ + unsigned long *ptr = addr, tmp; + long ret; + int pid = task->mm->context.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 or thread.fs being set instead). So, we let the host + * fiddle the registers and thread struct and restore the + * registers 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: + ret = restore_registers(pid, ¤t->thread.regs.regs); + if (ret) + return ret; + 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.arch.fs = (unsigned long) ptr; + ret = save_registers(pid, ¤t->thread.regs.regs); + break; + case ARCH_SET_GS: + ret = save_registers(pid, ¤t->thread.regs.regs); + break; + case ARCH_GET_FS: + ret = put_user(tmp, addr); + break; + case ARCH_GET_GS: + ret = put_user(tmp, addr); + break; + } + + return ret; +} + +long sys_arch_prctl(int code, unsigned long addr) +{ + return arch_prctl(current, code, (unsigned long __user *) addr); +} + +long sys_clone(unsigned long clone_flags, unsigned long newsp, + void __user *parent_tid, void __user *child_tid) +{ + long ret; + + if (!newsp) + newsp = UPT_SP(¤t->thread.regs.regs); + current->thread.forking = 1; + ret = do_fork(clone_flags, newsp, ¤t->thread.regs, 0, parent_tid, + child_tid); + current->thread.forking = 0; + return ret; +} + +void arch_switch_to(struct task_struct *to) +{ + if ((to->thread.arch.fs == 0) || (to->mm == NULL)) + return; + + arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs); +} |