diff options
| -rw-r--r-- | Documentation/lguest/lguest.c | 32 | ||||
| -rw-r--r-- | arch/x86/lguest/boot.c | 11 | ||||
| -rw-r--r-- | drivers/lguest/core.c | 2 | ||||
| -rw-r--r-- | drivers/lguest/hypercalls.c | 6 | ||||
| -rw-r--r-- | include/asm-x86/lguest_hcall.h | 6 |
5 files changed, 50 insertions, 7 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 9b0e322118b5..86cac3e622ab 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -153,6 +153,9 @@ struct virtqueue void (*handle_output)(int fd, struct virtqueue *me); }; +/* Remember the arguments to the program so we can "reboot" */ +static char **main_args; + /* Since guest is UP and we don't run at the same time, we don't need barriers. * But I include them in the code in case others copy it. */ #define wmb() @@ -1489,7 +1492,9 @@ static void setup_block_file(const char *filename) /* Create stack for thread and run it */ stack = malloc(32768); - if (clone(io_thread, stack + 32768, CLONE_VM, dev) == -1) + /* SIGCHLD - We dont "wait" for our cloned thread, so prevent it from + * becoming a zombie. */ + if (clone(io_thread, stack + 32768, CLONE_VM | SIGCHLD, dev) == -1) err(1, "Creating clone"); /* We don't need to keep the I/O thread's end of the pipes open. */ @@ -1499,7 +1504,21 @@ static void setup_block_file(const char *filename) verbose("device %u: virtblock %llu sectors\n", devices.device_num, cap); } -/* That's the end of device setup. */ +/* That's the end of device setup. :*/ + +/* Reboot */ +static void __attribute__((noreturn)) restart_guest(void) +{ + unsigned int i; + + /* Closing pipes causes the waker thread and io_threads to die, and + * closing /dev/lguest cleans up the Guest. Since we don't track all + * open fds, we simply close everything beyond stderr. */ + for (i = 3; i < FD_SETSIZE; i++) + close(i); + execv(main_args[0], main_args); + err(1, "Could not exec %s", main_args[0]); +} /*L:220 Finally we reach the core of the Launcher, which runs the Guest, serves * its input and output, and finally, lays it to rest. */ @@ -1523,6 +1542,9 @@ static void __attribute__((noreturn)) run_guest(int lguest_fd) char reason[1024] = { 0 }; read(lguest_fd, reason, sizeof(reason)-1); errx(1, "%s", reason); + /* ERESTART means that we need to reboot the guest */ + } else if (errno == ERESTART) { + restart_guest(); /* EAGAIN means the Waker wanted us to look at some input. * Anything else means a bug or incompatible change. */ } else if (errno != EAGAIN) @@ -1571,6 +1593,12 @@ int main(int argc, char *argv[]) /* If they specify an initrd file to load. */ const char *initrd_name = NULL; + /* Save the args: we "reboot" by execing ourselves again. */ + main_args = argv; + /* We don't "wait" for the children, so prevent them from becoming + * zombies. */ + signal(SIGCHLD, SIG_IGN); + /* First we initialize the device list. Since console and network * device receive input from a file descriptor, we keep an fdset * (infds) and the maximum fd number (max_infd) with the head of the diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 92c56117eae5..d6b18e2e5431 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -67,6 +67,7 @@ #include <asm/mce.h> #include <asm/io.h> #include <asm/i387.h> +#include <asm/reboot.h> /* for struct machine_ops */ /*G:010 Welcome to the Guest! * @@ -812,7 +813,7 @@ static void lguest_safe_halt(void) * rather than virtual addresses, so we use __pa() here. */ static void lguest_power_off(void) { - hcall(LHCALL_CRASH, __pa("Power down"), 0, 0); + hcall(LHCALL_SHUTDOWN, __pa("Power down"), LGUEST_SHUTDOWN_POWEROFF, 0); } /* @@ -822,7 +823,7 @@ static void lguest_power_off(void) */ static int lguest_panic(struct notifier_block *nb, unsigned long l, void *p) { - hcall(LHCALL_CRASH, __pa(p), 0, 0); + hcall(LHCALL_SHUTDOWN, __pa(p), LGUEST_SHUTDOWN_POWEROFF, 0); /* The hcall won't return, but to keep gcc happy, we're "done". */ return NOTIFY_DONE; } @@ -926,6 +927,11 @@ static unsigned lguest_patch(u8 type, u16 clobber, void *ibuf, return insn_len; } +static void lguest_restart(char *reason) +{ + hcall(LHCALL_SHUTDOWN, __pa(reason), LGUEST_SHUTDOWN_RESTART, 0); +} + /*G:030 Once we get to lguest_init(), we know we're a Guest. The pv_ops * structures in the kernel provide points for (almost) every routine we have * to override to avoid privileged instructions. */ @@ -1059,6 +1065,7 @@ __init void lguest_init(void) * the Guest routine to power off. */ pm_power_off = lguest_power_off; + machine_ops.restart = lguest_restart; /* Now we're set up, call start_kernel() in init/main.c and we proceed * to boot as normal. It never returns. */ start_kernel(); diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index f10abc8d7635..c1069bceba11 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -235,6 +235,8 @@ int run_guest(struct lguest *lg, unsigned long __user *user) lguest_arch_handle_trap(lg); } + if (lg->dead == ERR_PTR(-ERESTART)) + return -ERESTART; /* The Guest is dead => "No such file or directory" */ return -ENOENT; } diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index b478affe8f91..05fad6fa8049 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -41,8 +41,8 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args) * do that. */ kill_guest(lg, "already have lguest_data"); break; - case LHCALL_CRASH: { - /* Crash is such a trivial hypercall that we do it in four + case LHCALL_SHUTDOWN: { + /* Shutdown is such a trivial hypercall that we do it in four * lines right here. */ char msg[128]; /* If the lgread fails, it will call kill_guest() itself; the @@ -50,6 +50,8 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args) __lgread(lg, msg, args->arg1, sizeof(msg)); msg[sizeof(msg)-1] = '\0'; kill_guest(lg, "CRASH: %s", msg); + if (args->arg2 == LGUEST_SHUTDOWN_RESTART) + lg->dead = ERR_PTR(-ERESTART); break; } case LHCALL_FLUSH_TLB: diff --git a/include/asm-x86/lguest_hcall.h b/include/asm-x86/lguest_hcall.h index 2091779e91fb..758b9a5d4539 100644 --- a/include/asm-x86/lguest_hcall.h +++ b/include/asm-x86/lguest_hcall.h @@ -4,7 +4,7 @@ #define LHCALL_FLUSH_ASYNC 0 #define LHCALL_LGUEST_INIT 1 -#define LHCALL_CRASH 2 +#define LHCALL_SHUTDOWN 2 #define LHCALL_LOAD_GDT 3 #define LHCALL_NEW_PGTABLE 4 #define LHCALL_FLUSH_TLB 5 @@ -20,6 +20,10 @@ #define LGUEST_TRAP_ENTRY 0x1F +/* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */ +#define LGUEST_SHUTDOWN_POWEROFF 1 +#define LGUEST_SHUTDOWN_RESTART 2 + #ifndef __ASSEMBLY__ #include <asm/hw_irq.h> |
