36decba90b
I am a lamer :-(. Luckily, Luo Xin performed LTP testing and found this failure. Btw, the fact that the patch in which I introduced this was merged shows that: a) I'm really trusted by people b) sometimes they're wrong about point a). c) lack of time for reviewers. CC: Luo Xin <luothing@sina.com> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
110 lines
2 KiB
C
110 lines
2 KiB
C
/*
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* Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#include "linux/config.h"
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#include "linux/sched.h"
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#include "linux/slab.h"
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#include "linux/types.h"
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#include "asm/uaccess.h"
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#include "asm/ptrace.h"
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#include "asm/smp.h"
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#include "asm/ldt.h"
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#include "choose-mode.h"
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#include "kern.h"
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#include "mode_kern.h"
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#ifdef CONFIG_MODE_TT
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extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
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static int do_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
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{
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return modify_ldt(func, ptr, bytecount);
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}
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#endif
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#ifdef CONFIG_MODE_SKAS
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#include "skas.h"
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#include "skas_ptrace.h"
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static int do_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
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{
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struct ptrace_ldt ldt;
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u32 cpu;
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int res;
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ldt = ((struct ptrace_ldt) { .func = func,
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.ptr = ptr,
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.bytecount = bytecount });
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cpu = get_cpu();
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res = ptrace(PTRACE_LDT, userspace_pid[cpu], 0, (unsigned long) &ldt);
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put_cpu();
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return res;
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}
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#endif
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int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
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{
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struct user_desc info;
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int res = 0;
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void *buf = NULL;
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void *p = NULL; /* What we pass to host. */
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switch(func){
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case 1:
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case 0x11: /* write_ldt */
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/* Do this check now to avoid overflows. */
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if (bytecount != sizeof(struct user_desc)) {
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res = -EINVAL;
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goto out;
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}
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if(copy_from_user(&info, ptr, sizeof(info))) {
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res = -EFAULT;
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goto out;
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}
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p = &info;
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break;
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case 0:
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case 2: /* read_ldt */
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/* The use of info avoids kmalloc on the write case, not on the
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* read one. */
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buf = kmalloc(bytecount, GFP_KERNEL);
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if (!buf) {
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res = -ENOMEM;
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goto out;
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}
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p = buf;
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break;
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default:
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res = -ENOSYS;
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goto out;
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}
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res = CHOOSE_MODE_PROC(do_modify_ldt_tt, do_modify_ldt_skas, func,
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p, bytecount);
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if(res < 0)
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goto out;
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switch(func){
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case 0:
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case 2:
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/* Modify_ldt was for reading and returned the number of read
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* bytes.*/
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if(copy_to_user(ptr, p, res))
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res = -EFAULT;
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break;
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}
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out:
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kfree(buf);
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return res;
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}
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