* Accessing sysenter page by kernel syscalls
@ 2004-05-04 16:54 Petr Vandrovec
0 siblings, 0 replies; only message in thread
From: Petr Vandrovec @ 2004-05-04 16:54 UTC (permalink / raw)
To: linux-kernel
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
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2004-05-04 16:55 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-05-04 16:54 Accessing sysenter page by kernel syscalls Petr Vandrovec
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®