#include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * We don't expose the real in-memory order of objects for security reasons. * But still the comparison results should be suitable for sorting. So we * obfuscate kernel pointers values and compare the production instead. * * The obfuscation is done in two steps. First we xor the kernel pointer with * a random value, which puts pointer into a new position in a reordered space. * Secondly we multiply the xor production with a large odd random number to * permute its bits even more (the odd multiplier guarantees that the product * is unique ever after the high bits are truncated, since any odd number is * relative prime to 2^n). * * Note also that the obfuscation itself is invisible to userspace and if needed * it can be changed to an alternate scheme. */ static unsigned long cookies[KCMP_TYPES][2] __read_mostly; static long kptr_obfuscate(long v, int type) { return (v ^ cookies[type][0]) * cookies[type][1]; } /* * 0 - equal, i.e. v1 = v2 * 1 - less than, i.e. v1 < v2 * 2 - greater than, i.e. v1 > v2 * 3 - not equal but ordering unavailable (reserved for future) */ static int kcmp_ptr(void *v1, void *v2, enum kcmp_type type) { long t1, t2; t1 = kptr_obfuscate((long)v1, type); t2 = kptr_obfuscate((long)v2, type); return (t1 < t2) | ((t1 > t2) << 1); } /* The caller must have pinned the task */ static struct file * get_file_raw_ptr(struct task_struct *task, unsigned int idx) { struct file *file = NULL; task_lock(task); rcu_read_lock(); if (task->files) file = fcheck_files(task->files, idx); rcu_read_unlock(); task_unlock(task); return file; } static void kcmp_unlock(struct mutex *m1, struct mutex *m2) { if (likely(m2 != m1)) mutex_unlock(m2); mutex_unlock(m1); } static int kcmp_lock(struct mutex *m1, struct mutex *m2) { int err; if (m2 > m1) swap(m1, m2); err = mutex_lock_killable(m1); if (!err && likely(m1 != m2)) { err = mutex_lock_killable_nested(m2, SINGLE_DEPTH_NESTING); if (err) mutex_unlock(m1); } return err; } SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type, unsigned long, idx1, unsigned long, idx2) { struct task_struct *task1, *task2; int ret; rcu_read_lock(); /* * Tasks are looked up in caller's PID namespace only. */ task1 = find_task_by_vpid(pid1); task2 = find_task_by_vpid(pid2); if (!task1 || !task2) goto err_no_task; get_task_struct(task1); get_task_struct(task2); rcu_read_unlock(); /* * One should have enough rights to inspect task details. */ ret = kcmp_lock(&task1->signal->cred_guard_mutex, &task2->signal->cred_guard_mutex); if (ret) goto err; if (!ptrace_may_access(task1, PTRACE_MODE_READ_REALCREDS) || !ptrace_may_access(task2, PTRACE_MODE_READ_REALCREDS)) { ret = -EPERM; goto err_unlock; } switch (type) { case KCMP_FILE: { struct file *filp1, *filp2; filp1 = get_file_raw_ptr(task1, idx1); filp2 = get_file_raw_ptr(task2, idx2); if (filp1 && filp2) ret = kcmp_ptr(filp1, filp2, KCMP_FILE); else ret = -EBADF; break; } case KCMP_VM: ret = kcmp_ptr(task1->mm, task2->mm, KCMP_VM); break; case KCMP_FILES: ret = kcmp_ptr(task1->files, task2->files, KCMP_FILES); break; case KCMP_FS: ret = kcmp_ptr(task1->fs, task2->fs, KCMP_FS); break; case KCMP_SIGHAND: ret = kcmp_ptr(task1->sighand, task2->sighand, KCMP_SIGHAND); break; case KCMP_IO: ret = kcmp_ptr(task1->io_context, task2->io_context, KCMP_IO); break; case KCMP_SYSVSEM: #ifdef CONFIG_SYSVIPC ret = kcmp_ptr(task1->sysvsem.undo_list, task2->sysvsem.undo_list, KCMP_SYSVSEM); #else ret = -EOPNOTSUPP; #endif break; default: ret = -EINVAL; break; } err_unlock: kcmp_unlock(&task1->signal->cred_guard_mutex, &task2->signal->cred_guard_mutex); err: put_task_struct(task1); put_task_struct(task2); return ret; err_no_task: rcu_read_unlock(); return -ESRCH; } static __init int kcmp_cookies_init(void) { int i; get_random_bytes(cookies, sizeof(cookies)); for (i = 0; i < KCMP_TYPES; i++) cookies[i][1] |= (~(~0UL >> 1) | 1); return 0; } arch_initcall(kcmp_cookies_init); emode:
authorTobias Klauser <tklauser@distanz.ch>2016-10-20 15:44:19 +0200
committerTobias Klauser <tklauser@distanz.ch>2017-02-15 10:34:18 +0100
commit5db4992d8f040b8d8db0b86d42806e0c417f7ccf (patch)
tree5b06e952af482d45f3ade64e77824662e34b7fa2 /Documentation/devicetree/bindings/net/dsa/marvell.txt
parent370ebb0ef6255132373ed35d13e7b1d8d2eb7003 (diff)
usbnet: pegasus: Use net_device_stats from struct net_devicends-private-remove
Instead of using a private copy of struct net_device_stats in struct pegasus, use stats from struct net_device. Also remove the now unnecessary .ndo_get_stats function. Cc: Petko Manolov <petkan@nucleusys.com> Cc: linux-usb@vger.kernel.org Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Diffstat (limited to 'Documentation/devicetree/bindings/net/dsa/marvell.txt')