linux_dsm_epyc7002/arch/um/kernel/tt/uaccess.c
Paolo 'Blaisorblade' Giarrusso 7a590611c0 [PATCH] uml: fix access_ok
The access_ok_tt() macro is bogus, in that a read access is unconditionally
considered valid.

I couldn't find in SCM logs the introduction of this check, but I went back to
2.4.20-1um and the definition was the same.

Possibly this was done to avoid problems with missing set_fs() calls, but
there can't be any I think because they would fail with SKAS mode.
TT-specific code is still to check.

Also, this patch joins common code together, and makes the "address range
wrapping" check happen for all cases, rather than for only some.

This may, possibly, be reoptimized at some time, but the current code doesn't
seem clever, just confused.

* Important: I've also had to change references to access_ok_{tt,skas} back to
  access_ok - the kernel wasn't that happy otherwise.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:15 -08:00

74 lines
1.8 KiB
C

/*
* Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include "linux/sched.h"
#include "asm/uaccess.h"
int copy_from_user_tt(void *to, const void __user *from, int n)
{
if(!access_ok(VERIFY_READ, from, n))
return(n);
return(__do_copy_from_user(to, from, n, &current->thread.fault_addr,
&current->thread.fault_catcher));
}
int copy_to_user_tt(void __user *to, const void *from, int n)
{
if(!access_ok(VERIFY_WRITE, to, n))
return(n);
return(__do_copy_to_user(to, from, n, &current->thread.fault_addr,
&current->thread.fault_catcher));
}
int strncpy_from_user_tt(char *dst, const char __user *src, int count)
{
int n;
if(!access_ok(VERIFY_READ, src, 1))
return(-EFAULT);
n = __do_strncpy_from_user(dst, src, count,
&current->thread.fault_addr,
&current->thread.fault_catcher);
if(n < 0) return(-EFAULT);
return(n);
}
int __clear_user_tt(void __user *mem, int len)
{
return(__do_clear_user(mem, len,
&current->thread.fault_addr,
&current->thread.fault_catcher));
}
int clear_user_tt(void __user *mem, int len)
{
if(!access_ok(VERIFY_WRITE, mem, len))
return(len);
return(__do_clear_user(mem, len, &current->thread.fault_addr,
&current->thread.fault_catcher));
}
int strnlen_user_tt(const void __user *str, int len)
{
return(__do_strnlen_user(str, len,
&current->thread.fault_addr,
&current->thread.fault_catcher));
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/