From: David Stroupe <dstroupe@keyed-upsoftware.com>
To: linux-kernel@vger.kernel.org
Subject: mmap issues
Date: Wed, 08 May 2002 18:02:13 -0500 [thread overview]
Message-ID: <3CD9AE75.60105@keyed-upsoftware.com> (raw)
In the driver is:
static int S_Mmap(struct file * flip, struct vm_area_struct *vma)
{
<snip>
unsigned long size = (unsigned long)vma->vm_end - vma->vm_start;
<------size = 2000 for this case
unsigned long start = (unsigned long)vma->vm_start;
vma->vm_flags |= VM_LOCKED;
vaddy = kmalloc(size , GFP_KERNEL);
strcpy((char*)vaddy, "testing\0");
mem_map_reserve(virt_to_page(vaddy));
result = remap_page_range(start, virt_to_phys(vaddy), size,
vma->vm_page_prot);
if (result)
return -EAGAIN;
return 0;
in user space is:
<snip>
pdma->dwBytes = 2000;
pdma->pUserAddr = mmap(0, pdma->dwBytes, PROT_READ | PROT_WRITE,
MAP_SHARED, hWd, 0);
str = (char*)pdma->pUserAddr;
<snip)
when I try to view the memory that I just mmap()ed using gdb I see:
$12 = 0x40018000 <Address 0x40018000 out of bounds>
If I don't do the mem_map_reserve() command I can view the memory but it
is all zeros.
What am I missing?
TIA
--
Best regards,
David Stroupe
Keyed-Up Software
next reply other threads:[~2002-05-08 23:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-05-08 23:02 David Stroupe [this message]
-- strict thread matches above, loose matches on Subject: below --
2001-11-27 16:46 MMAP issues Peter Zaitsev
[not found] ` <3C03D108.E3FADE95@zip.com.au>
2001-11-27 17:54 ` Re[2]: " Peter Zaitsev
2001-11-27 22:36 ` Jeff Epler
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