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Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

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* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: update comments to reflect LHCALL_LOAD_GDT_ENTRY.
  virtio: console: Prevent userspace from submitting NULL buffers
  virtio: console: Fix poll blocking even though there is data to read
This commit is contained in:
Linus Torvalds
2010-09-21 11:00:09 -07:00
parent b30a3f6257 9b6efcd2e2
commit 4e24db5b1a
2 changed files with 13 additions and 6 deletions
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13
arch/x86/lguest/boot.c
View File

@@ -324,9 +324,8 @@ static void lguest_load_gdt(const struct desc_ptr *desc)
} }
/* /*
* For a single GDT entry which changes, we do the lazy thing: alter our GDT, * For a single GDT entry which changes, we simply change our copy and
* then tell the Host to reload the entire thing. This operation is so rare * then tell the host about it.
* that this naive implementation is reasonable.
*/ */
static void lguest_write_gdt_entry(struct desc_struct *dt, int entrynum, static void lguest_write_gdt_entry(struct desc_struct *dt, int entrynum,
const void *desc, int type) const void *desc, int type)
@@ -338,9 +337,13 @@ static void lguest_write_gdt_entry(struct desc_struct *dt, int entrynum,
} }
/* /*
* OK, I lied. There are three "thread local storage" GDT entries which change * There are three "thread local storage" GDT entries which change
* on every context switch (these three entries are how glibc implements * on every context switch (these three entries are how glibc implements
* __thread variables). So we have a hypercall specifically for this case. * __thread variables). As an optimization, we have a hypercall
* specifically for this case.
*
* Wouldn't it be nicer to have a general LOAD_GDT_ENTRIES hypercall
* which took a range of entries?
*/ */
static void lguest_load_tls(struct thread_struct *t, unsigned int cpu) static void lguest_load_tls(struct thread_struct *t, unsigned int cpu)
{ {

6
drivers/char/virtio_console.c
View File

@@ -596,6 +596,10 @@ static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
ssize_t ret; ssize_t ret;
bool nonblock; bool nonblock;
/* Userspace could be out to fool us */
if (!count)
return 0;
port = filp->private_data; port = filp->private_data;
nonblock = filp->f_flags & O_NONBLOCK; nonblock = filp->f_flags & O_NONBLOCK;
@@ -642,7 +646,7 @@ static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
poll_wait(filp, &port->waitqueue, wait); poll_wait(filp, &port->waitqueue, wait);
ret = 0; ret = 0;
if (port->inbuf) if (!will_read_block(port))
ret |= POLLIN | POLLRDNORM; ret |= POLLIN | POLLRDNORM;
if (!will_write_block(port)) if (!will_write_block(port))
ret |= POLLOUT; ret |= POLLOUT;