lguest: fix comment style
I don't really notice it (except to begrudge the extra vertical
space), but Ingo does. And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index a6974e9..cd058bc 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -1,6 +1,8 @@
-/*P:400 This contains run_guest() which actually calls into the Host<->Guest
+/*P:400
+ * This contains run_guest() which actually calls into the Host<->Guest
* Switcher and analyzes the return, such as determining if the Guest wants the
- * Host to do something. This file also contains useful helper routines. :*/
+ * Host to do something. This file also contains useful helper routines.
+:*/
#include <linux/module.h>
#include <linux/stringify.h>
#include <linux/stddef.h>
@@ -24,7 +26,8 @@
/* This One Big lock protects all inter-guest data structures. */
DEFINE_MUTEX(lguest_lock);
-/*H:010 We need to set up the Switcher at a high virtual address. Remember the
+/*H:010
+ * We need to set up the Switcher at a high virtual address. Remember the
* Switcher is a few hundred bytes of assembler code which actually changes the
* CPU to run the Guest, and then changes back to the Host when a trap or
* interrupt happens.
@@ -33,7 +36,8 @@
* Host since it will be running as the switchover occurs.
*
* Trying to map memory at a particular address is an unusual thing to do, so
- * it's not a simple one-liner. */
+ * it's not a simple one-liner.
+ */
static __init int map_switcher(void)
{
int i, err;
@@ -47,8 +51,10 @@
* easy.
*/
- /* We allocate an array of struct page pointers. map_vm_area() wants
- * this, rather than just an array of pages. */
+ /*
+ * We allocate an array of struct page pointers. map_vm_area() wants
+ * this, rather than just an array of pages.
+ */
switcher_page = kmalloc(sizeof(switcher_page[0])*TOTAL_SWITCHER_PAGES,
GFP_KERNEL);
if (!switcher_page) {
@@ -56,8 +62,10 @@
goto out;
}
- /* Now we actually allocate the pages. The Guest will see these pages,
- * so we make sure they're zeroed. */
+ /*
+ * Now we actually allocate the pages. The Guest will see these pages,
+ * so we make sure they're zeroed.
+ */
for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) {
unsigned long addr = get_zeroed_page(GFP_KERNEL);
if (!addr) {
@@ -67,19 +75,23 @@
switcher_page[i] = virt_to_page(addr);
}
- /* First we check that the Switcher won't overlap the fixmap area at
+ /*
+ * First we check that the Switcher won't overlap the fixmap area at
* the top of memory. It's currently nowhere near, but it could have
- * very strange effects if it ever happened. */
+ * very strange effects if it ever happened.
+ */
if (SWITCHER_ADDR + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){
err = -ENOMEM;
printk("lguest: mapping switcher would thwack fixmap\n");
goto free_pages;
}
- /* Now we reserve the "virtual memory area" we want: 0xFFC00000
+ /*
+ * Now we reserve the "virtual memory area" we want: 0xFFC00000
* (SWITCHER_ADDR). We might not get it in theory, but in practice
* it's worked so far. The end address needs +1 because __get_vm_area
- * allocates an extra guard page, so we need space for that. */
+ * allocates an extra guard page, so we need space for that.
+ */
switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR
+ (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
@@ -89,11 +101,13 @@
goto free_pages;
}
- /* This code actually sets up the pages we've allocated to appear at
+ /*
+ * This code actually sets up the pages we've allocated to appear at
* SWITCHER_ADDR. map_vm_area() takes the vma we allocated above, the
* kind of pages we're mapping (kernel pages), and a pointer to our
* array of struct pages. It increments that pointer, but we don't
- * care. */
+ * care.
+ */
pagep = switcher_page;
err = map_vm_area(switcher_vma, PAGE_KERNEL_EXEC, &pagep);
if (err) {
@@ -101,8 +115,10 @@
goto free_vma;
}
- /* Now the Switcher is mapped at the right address, we can't fail!
- * Copy in the compiled-in Switcher code (from <arch>_switcher.S). */
+ /*
+ * Now the Switcher is mapped at the right address, we can't fail!
+ * Copy in the compiled-in Switcher code (from <arch>_switcher.S).
+ */
memcpy(switcher_vma->addr, start_switcher_text,
end_switcher_text - start_switcher_text);
@@ -124,8 +140,7 @@
}
/*:*/
-/* Cleaning up the mapping when the module is unloaded is almost...
- * too easy. */
+/* Cleaning up the mapping when the module is unloaded is almost... too easy. */
static void unmap_switcher(void)
{
unsigned int i;
@@ -151,16 +166,19 @@
* But we can't trust the Guest: it might be trying to access the Launcher
* code. We have to check that the range is below the pfn_limit the Launcher
* gave us. We have to make sure that addr + len doesn't give us a false
- * positive by overflowing, too. */
+ * positive by overflowing, too.
+ */
bool lguest_address_ok(const struct lguest *lg,
unsigned long addr, unsigned long len)
{
return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
}
-/* This routine copies memory from the Guest. Here we can see how useful the
+/*
+ * This routine copies memory from the Guest. Here we can see how useful the
* kill_lguest() routine we met in the Launcher can be: we return a random
- * value (all zeroes) instead of needing to return an error. */
+ * value (all zeroes) instead of needing to return an error.
+ */
void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
{
if (!lguest_address_ok(cpu->lg, addr, bytes)
@@ -181,9 +199,11 @@
}
/*:*/
-/*H:030 Let's jump straight to the the main loop which runs the Guest.
+/*H:030
+ * Let's jump straight to the the main loop which runs the Guest.
* Remember, this is called by the Launcher reading /dev/lguest, and we keep
- * going around and around until something interesting happens. */
+ * going around and around until something interesting happens.
+ */
int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
{
/* We stop running once the Guest is dead. */
@@ -195,8 +215,10 @@
if (cpu->hcall)
do_hypercalls(cpu);
- /* It's possible the Guest did a NOTIFY hypercall to the
- * Launcher, in which case we return from the read() now. */
+ /*
+ * It's possible the Guest did a NOTIFY hypercall to the
+ * Launcher, in which case we return from the read() now.
+ */
if (cpu->pending_notify) {
if (!send_notify_to_eventfd(cpu)) {
if (put_user(cpu->pending_notify, user))
@@ -209,29 +231,39 @@
if (signal_pending(current))
return -ERESTARTSYS;
- /* Check if there are any interrupts which can be delivered now:
+ /*
+ * Check if there are any interrupts which can be delivered now:
* if so, this sets up the hander to be executed when we next
- * run the Guest. */
+ * run the Guest.
+ */
irq = interrupt_pending(cpu, &more);
if (irq < LGUEST_IRQS)
try_deliver_interrupt(cpu, irq, more);
- /* All long-lived kernel loops need to check with this horrible
+ /*
+ * All long-lived kernel loops need to check with this horrible
* thing called the freezer. If the Host is trying to suspend,
- * it stops us. */
+ * it stops us.
+ */
try_to_freeze();
- /* Just make absolutely sure the Guest is still alive. One of
- * those hypercalls could have been fatal, for example. */
+ /*
+ * Just make absolutely sure the Guest is still alive. One of
+ * those hypercalls could have been fatal, for example.
+ */
if (cpu->lg->dead)
break;
- /* If the Guest asked to be stopped, we sleep. The Guest's
- * clock timer will wake us. */
+ /*
+ * If the Guest asked to be stopped, we sleep. The Guest's
+ * clock timer will wake us.
+ */
if (cpu->halted) {
set_current_state(TASK_INTERRUPTIBLE);
- /* Just before we sleep, make sure no interrupt snuck in
- * which we should be doing. */
+ /*
+ * Just before we sleep, make sure no interrupt snuck in
+ * which we should be doing.
+ */
if (interrupt_pending(cpu, &more) < LGUEST_IRQS)
set_current_state(TASK_RUNNING);
else
@@ -239,8 +271,10 @@
continue;
}
- /* OK, now we're ready to jump into the Guest. First we put up
- * the "Do Not Disturb" sign: */
+ /*
+ * OK, now we're ready to jump into the Guest. First we put up
+ * the "Do Not Disturb" sign:
+ */
local_irq_disable();
/* Actually run the Guest until something happens. */
@@ -327,8 +361,10 @@
}
/*:*/
-/* The Host side of lguest can be a module. This is a nice way for people to
- * play with it. */
+/*
+ * The Host side of lguest can be a module. This is a nice way for people to
+ * play with it.
+ */
module_init(init);
module_exit(fini);
MODULE_LICENSE("GPL");