From: "Petr Vandrovec" <VANDROVE@vc.cvut.cz>
To: linux-kernel@vger.kernel.org
Subject: Accessing sysenter page by kernel syscalls
Date: Tue, 4 May 2004 18:54:54 +0200 [thread overview]
Message-ID: <5737E6105A3@vcnet.vc.cvut.cz> (raw)
Hi,
is there any reason why copy_from_user does not punch hole in
kernel space to get it possible to access sysenter page? I do not think
that it would add too big overhead to copy_*_user (which is already long),
but I cannot think about any other reason why sysenter page is not
accessible through write().
Today I wanted to confirm whether my kernel uses sysenter or int 0x80,
and I found that simple program below does not work and I had to copy page
first to some temporary location, and then write it from this temporary
location to stdout.
void main(void) {
write(1, (void*)0xFFFFE000, 4096);
}
Thanks,
Petr Vandrovec
reply other threads:[~2004-05-04 16:55 UTC|newest]
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