Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
ba180fd4 | 2 | * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Copyright 2003 PathScale, Inc. |
4 | * | |
5 | * Licensed under the GPL | |
6 | */ | |
7 | ||
8 | #include "linux/linkage.h" | |
f7fe8781 | 9 | #include "linux/personality.h" |
ba180fd4 | 10 | #include "linux/utsname.h" |
1da177e4 | 11 | #include "asm/prctl.h" /* XXX This should get the constants from libc */ |
ba180fd4 | 12 | #include "asm/uaccess.h" |
f355559c | 13 | #include "os.h" |
1da177e4 | 14 | |
77bf4400 | 15 | long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr) |
1da177e4 | 16 | { |
ba180fd4 | 17 | unsigned long *ptr = addr, tmp; |
f355559c | 18 | long ret; |
6c738ffa | 19 | int pid = task->mm->context.id.u.pid; |
1da177e4 | 20 | |
f355559c JD |
21 | /* |
22 | * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to | |
23 | * be safe), we need to call arch_prctl on the host because | |
24 | * setting %fs may result in something else happening (like a | |
6e6d74cf JD |
25 | * GDT or thread.fs being set instead). So, we let the host |
26 | * fiddle the registers and thread struct and restore the | |
27 | * registers afterwards. | |
f355559c JD |
28 | * |
29 | * So, the saved registers are stored to the process (this | |
30 | * needed because a stub may have been the last thing to run), | |
31 | * arch_prctl is run on the host, then the registers are read | |
32 | * back. | |
33 | */ | |
ba180fd4 | 34 | switch (code) { |
1da177e4 | 35 | case ARCH_SET_FS: |
f767b02f | 36 | case ARCH_SET_GS: |
3e6f2ac4 JD |
37 | ret = restore_registers(pid, ¤t->thread.regs.regs); |
38 | if (ret) | |
39 | return ret; | |
ba180fd4 JD |
40 | break; |
41 | case ARCH_GET_FS: | |
42 | case ARCH_GET_GS: | |
43 | /* | |
44 | * With these two, we read to a local pointer and | |
45 | * put_user it to the userspace pointer that we were | |
46 | * given. If addr isn't valid (because it hasn't been | |
47 | * faulted in or is just bogus), we want put_user to | |
48 | * fault it in (or return -EFAULT) instead of having | |
49 | * the host return -EFAULT. | |
50 | */ | |
51 | ptr = &tmp; | |
52 | } | |
f355559c | 53 | |
ba180fd4 JD |
54 | ret = os_arch_prctl(pid, code, ptr); |
55 | if (ret) | |
56 | return ret; | |
f355559c | 57 | |
ba180fd4 | 58 | switch (code) { |
f355559c | 59 | case ARCH_SET_FS: |
44f5c4ce | 60 | current->thread.arch.fs = (unsigned long) ptr; |
3e6f2ac4 | 61 | ret = save_registers(pid, ¤t->thread.regs.regs); |
44f5c4ce | 62 | break; |
f355559c | 63 | case ARCH_SET_GS: |
3e6f2ac4 | 64 | ret = save_registers(pid, ¤t->thread.regs.regs); |
f767b02f | 65 | break; |
1da177e4 | 66 | case ARCH_GET_FS: |
f355559c | 67 | ret = put_user(tmp, addr); |
ba180fd4 | 68 | break; |
1da177e4 | 69 | case ARCH_GET_GS: |
f355559c | 70 | ret = put_user(tmp, addr); |
ba180fd4 | 71 | break; |
1da177e4 LT |
72 | } |
73 | ||
f355559c | 74 | return ret; |
1da177e4 | 75 | } |
1da177e4 LT |
76 | |
77 | long sys_arch_prctl(int code, unsigned long addr) | |
78 | { | |
77bf4400 | 79 | return arch_prctl(current, code, (unsigned long __user *) addr); |
1da177e4 LT |
80 | } |
81 | ||
82 | long sys_clone(unsigned long clone_flags, unsigned long newsp, | |
83 | void __user *parent_tid, void __user *child_tid) | |
84 | { | |
85 | long ret; | |
86 | ||
e0877f07 JD |
87 | if (!newsp) |
88 | newsp = UPT_SP(¤t->thread.regs.regs); | |
1da177e4 | 89 | current->thread.forking = 1; |
e0877f07 JD |
90 | ret = do_fork(clone_flags, newsp, ¤t->thread.regs, 0, parent_tid, |
91 | child_tid); | |
1da177e4 | 92 | current->thread.forking = 0; |
f355559c JD |
93 | return ret; |
94 | } | |
95 | ||
291248fd | 96 | void arch_switch_to(struct task_struct *to) |
f355559c | 97 | { |
ba180fd4 JD |
98 | if ((to->thread.arch.fs == 0) || (to->mm == NULL)) |
99 | return; | |
f355559c | 100 | |
ba180fd4 | 101 | arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs); |
1da177e4 | 102 | } |