diff options
| -rw-r--r-- | Documentation/lguest/lguest.c | 73 | ||||
| -rw-r--r-- | Documentation/lguest/lguest.txt | 5 | ||||
| -rw-r--r-- | arch/x86/lguest/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/lguest/boot.c | 2 | ||||
| -rw-r--r-- | drivers/lguest/page_tables.c | 2 | ||||
| -rw-r--r-- | drivers/lguest/x86/core.c | 4 | ||||
| -rw-r--r-- | drivers/virtio/virtio_pci.c | 20 |
7 files changed, 77 insertions, 30 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index dc73bc54cc4..d9da7e14853 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -39,6 +39,9 @@ #include <limits.h> #include <stddef.h> #include <signal.h> +#include <pwd.h> +#include <grp.h> + #include <linux/virtio_config.h> #include <linux/virtio_net.h> #include <linux/virtio_blk.h> @@ -298,20 +301,27 @@ static void *map_zeroed_pages(unsigned int num) /* * We use a private mapping (ie. if we write to the page, it will be - * copied). + * copied). We allocate an extra two pages PROT_NONE to act as guard + * pages against read/write attempts that exceed allocated space. */ - addr = mmap(NULL, getpagesize() * num, - PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, fd, 0); + addr = mmap(NULL, getpagesize() * (num+2), + PROT_NONE, MAP_PRIVATE, fd, 0); + if (addr == MAP_FAILED) err(1, "Mmapping %u pages of /dev/zero", num); + if (mprotect(addr + getpagesize(), getpagesize() * num, + PROT_READ|PROT_WRITE) == -1) + err(1, "mprotect rw %u pages failed", num); + /* * One neat mmap feature is that you can close the fd, and it * stays mapped. */ close(fd); - return addr; + /* Return address after PROT_NONE page */ + return addr + getpagesize(); } /* Get some more pages for a device. */ @@ -343,7 +353,7 @@ static void map_at(int fd, void *addr, unsigned long offset, unsigned long len) * done to it. This allows us to share untouched memory between * Guests. */ - if (mmap(addr, len, PROT_READ|PROT_WRITE|PROT_EXEC, + if (mmap(addr, len, PROT_READ|PROT_WRITE, MAP_FIXED|MAP_PRIVATE, fd, offset) != MAP_FAILED) return; @@ -573,10 +583,10 @@ static void *_check_pointer(unsigned long addr, unsigned int size, unsigned int line) { /* - * We have to separately check addr and addr+size, because size could - * be huge and addr + size might wrap around. + * Check if the requested address and size exceeds the allocated memory, + * or addr + size wraps around. */ - if (addr >= guest_limit || addr + size >= guest_limit) + if ((addr + size) > guest_limit || (addr + size) < addr) errx(1, "%s:%i: Invalid address %#lx", __FILE__, line, addr); /* * We return a pointer for the caller's convenience, now we know it's @@ -1872,6 +1882,8 @@ static struct option opts[] = { { "block", 1, NULL, 'b' }, { "rng", 0, NULL, 'r' }, { "initrd", 1, NULL, 'i' }, + { "username", 1, NULL, 'u' }, + { "chroot", 1, NULL, 'c' }, { NULL }, }; static void usage(void) @@ -1894,6 +1906,12 @@ int main(int argc, char *argv[]) /* If they specify an initrd file to load. */ const char *initrd_name = NULL; + /* Password structure for initgroups/setres[gu]id */ + struct passwd *user_details = NULL; + + /* Directory to chroot to */ + char *chroot_path = NULL; + /* Save the args: we "reboot" by execing ourselves again. */ main_args = argv; @@ -1950,6 +1968,14 @@ int main(int argc, char *argv[]) case 'i': initrd_name = optarg; break; + case 'u': + user_details = getpwnam(optarg); + if (!user_details) + err(1, "getpwnam failed, incorrect username?"); + break; + case 'c': + chroot_path = optarg; + break; default: warnx("Unknown argument %s", argv[optind]); usage(); @@ -2021,6 +2047,37 @@ int main(int argc, char *argv[]) /* If we exit via err(), this kills all the threads, restores tty. */ atexit(cleanup_devices); + /* If requested, chroot to a directory */ + if (chroot_path) { + if (chroot(chroot_path) != 0) + err(1, "chroot(\"%s\") failed", chroot_path); + + if (chdir("/") != 0) + err(1, "chdir(\"/\") failed"); + + verbose("chroot done\n"); + } + + /* If requested, drop privileges */ + if (user_details) { + uid_t u; + gid_t g; + + u = user_details->pw_uid; + g = user_details->pw_gid; + + if (initgroups(user_details->pw_name, g) != 0) + err(1, "initgroups failed"); + + if (setresgid(g, g, g) != 0) + err(1, "setresgid failed"); + + if (setresuid(u, u, u) != 0) + err(1, "setresuid failed"); + + verbose("Dropping privileges completed\n"); + } + /* Finally, run the Guest. This doesn't return. */ run_guest(); } diff --git a/Documentation/lguest/lguest.txt b/Documentation/lguest/lguest.txt index 6ccaf8e1a00..dad99978a6a 100644 --- a/Documentation/lguest/lguest.txt +++ b/Documentation/lguest/lguest.txt @@ -117,6 +117,11 @@ Running Lguest: for general information on how to get bridging to work. +- Random number generation. Using the --rng option will provide a + /dev/hwrng in the guest that will read from the host's /dev/random. + Use this option in conjunction with rng-tools (see ../hw_random.txt) + to provide entropy to the guest kernel's /dev/random. + There is a helpful mailing list at http://ozlabs.org/mailman/listinfo/lguest Good luck! diff --git a/arch/x86/lguest/Kconfig b/arch/x86/lguest/Kconfig index 38718041efc..6e121a2a49e 100644 --- a/arch/x86/lguest/Kconfig +++ b/arch/x86/lguest/Kconfig @@ -2,6 +2,7 @@ config LGUEST_GUEST bool "Lguest guest support" select PARAVIRT depends on X86_32 + select VIRTUALIZATION select VIRTIO select VIRTIO_RING select VIRTIO_CONSOLE diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 4996cf5f73a..eba687f0cc0 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -824,7 +824,7 @@ static void __init lguest_init_IRQ(void) for (i = FIRST_EXTERNAL_VECTOR; i < NR_VECTORS; i++) { /* Some systems map "vectors" to interrupts weirdly. Not us! */ - __get_cpu_var(vector_irq)[i] = i - FIRST_EXTERNAL_VECTOR; + __this_cpu_write(vector_irq[i], i - FIRST_EXTERNAL_VECTOR); if (i != SYSCALL_VECTOR) set_intr_gate(i, interrupt[i - FIRST_EXTERNAL_VECTOR]); } diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index 04b22128a47..d21578ee95d 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -1137,7 +1137,7 @@ void free_guest_pagetable(struct lguest *lg) */ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages) { - pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages); + pte_t *switcher_pte_page = __this_cpu_read(switcher_pte_pages); pte_t regs_pte; #ifdef CONFIG_X86_PAE diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index b4eb675a807..9f1659c3d1f 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -90,8 +90,8 @@ static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages) * meanwhile). If that's not the case, we pretend everything in the * Guest has changed. */ - if (__get_cpu_var(lg_last_cpu) != cpu || cpu->last_pages != pages) { - __get_cpu_var(lg_last_cpu) = cpu; + if (__this_cpu_read(lg_last_cpu) != cpu || cpu->last_pages != pages) { + __this_cpu_write(lg_last_cpu, cpu); cpu->last_pages = pages; cpu->changed = CHANGED_ALL; } diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index ef8d9d558fc..4fb5b2bf234 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -96,11 +96,6 @@ static struct pci_device_id virtio_pci_id_table[] = { MODULE_DEVICE_TABLE(pci, virtio_pci_id_table); -/* A PCI device has it's own struct device and so does a virtio device so - * we create a place for the virtio devices to show up in sysfs. I think it - * would make more sense for virtio to not insist on having it's own device. */ -static struct device *virtio_pci_root; - /* Convert a generic virtio device to our structure */ static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev) { @@ -629,7 +624,7 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev, if (vp_dev == NULL) return -ENOMEM; - vp_dev->vdev.dev.parent = virtio_pci_root; + vp_dev->vdev.dev.parent = &pci_dev->dev; vp_dev->vdev.dev.release = virtio_pci_release_dev; vp_dev->vdev.config = &virtio_pci_config_ops; vp_dev->pci_dev = pci_dev; @@ -717,17 +712,7 @@ static struct pci_driver virtio_pci_driver = { static int __init virtio_pci_init(void) { - int err; - - virtio_pci_root = root_device_register("virtio-pci"); - if (IS_ERR(virtio_pci_root)) - return PTR_ERR(virtio_pci_root); - - err = pci_register_driver(&virtio_pci_driver); - if (err) - root_device_unregister(virtio_pci_root); - - return err; + return pci_register_driver(&virtio_pci_driver); } module_init(virtio_pci_init); @@ -735,7 +720,6 @@ module_init(virtio_pci_init); static void __exit virtio_pci_exit(void) { pci_unregister_driver(&virtio_pci_driver); - root_device_unregister(virtio_pci_root); } module_exit(virtio_pci_exit); |