diff options
Diffstat (limited to 'drivers/lguest/lguest_user.c')
| -rw-r--r-- | drivers/lguest/lguest_user.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c index bd1632388e4..4263f4cc8c5 100644 --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lguest_user.c @@ -1,8 +1,10 @@ -/*P:200 This contains all the /dev/lguest code, whereby the userspace launcher - * controls and communicates with the Guest. For example, the first write will - * tell us the Guest's memory layout and entry point. A read will run the - * Guest until something happens, such as a signal or the Guest doing a NOTIFY - * out to the Launcher. +/*P:200 This contains all the /dev/lguest code, whereby the userspace + * launcher controls and communicates with the Guest. For example, + * the first write will tell us the Guest's memory layout and entry + * point. A read will run the Guest until something happens, such as + * a signal or the Guest doing a NOTIFY out to the Launcher. There is + * also a way for the Launcher to attach eventfds to particular NOTIFY + * values instead of returning from the read() call. :*/ #include <linux/uaccess.h> #include <linux/miscdevice.h> @@ -10,6 +12,8 @@ #include <linux/sched.h> #include <linux/eventfd.h> #include <linux/file.h> +#include <linux/slab.h> +#include <linux/export.h> #include "lg.h" /*L:056 @@ -129,7 +133,7 @@ static int add_eventfd(struct lguest *lg, unsigned long addr, int fd) rcu_assign_pointer(lg->eventfds, new); /* - * We're not in a big hurry. Wait until noone's looking at old + * We're not in a big hurry. Wait until no one's looking at old * version, then free it. */ synchronize_rcu(); @@ -246,13 +250,13 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o) */ static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip) { - /* We have a limited number the number of CPUs in the lguest struct. */ + /* We have a limited number of CPUs in the lguest struct. */ if (id >= ARRAY_SIZE(cpu->lg->cpus)) return -EINVAL; /* Set up this CPU's id, and pointer back to the lguest struct. */ cpu->id = id; - cpu->lg = container_of((cpu - id), struct lguest, cpus[0]); + cpu->lg = container_of(cpu, struct lguest, cpus[id]); cpu->lg->nr_cpus++; /* Each CPU has a timer it can set. */ @@ -266,7 +270,7 @@ static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip) if (!cpu->regs_page) return -ENOMEM; - /* We actually put the registers at the bottom of the page. */ + /* We actually put the registers at the end of the page. */ cpu->regs = (void *)cpu->regs_page + PAGE_SIZE - sizeof(*cpu->regs); /* @@ -356,8 +360,8 @@ static int initialize(struct file *file, const unsigned long __user *input) goto free_eventfds; /* - * Initialize the Guest's shadow page tables, using the toplevel - * address the Launcher gave us. This allocates memory, so can fail. + * Initialize the Guest's shadow page tables. This allocates + * memory, so can fail. */ err = init_guest_pagetable(lg); if (err) @@ -513,7 +517,9 @@ static const struct file_operations lguest_fops = { .release = close, .write = write, .read = read, + .llseek = default_llseek, }; +/*:*/ /* * This is a textbook example of a "misc" character device. Populate a "struct |