#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "xenbus_comms.h" static int xenbus_backend_open(struct inode *inode, struct file *filp) { if (!capable(CAP_SYS_ADMIN)) return -EPERM; return nonseekable_open(inode, filp); } static long xenbus_alloc(domid_t domid) { struct evtchn_alloc_unbound arg; int err = -EEXIST; xs_suspend(); /* If xenstored_ready is nonzero, that means we have already talked to * xenstore and set up watches. These watches will be restored by * xs_resume, but that requires communication over the port established * below that is not visible to anyone until the ioctl returns. * * This can be resolved by splitting the ioctl into two parts * (postponing the resume until xenstored is active) but this is * unnecessarily complex for the intended use where xenstored is only * started once - so return -EEXIST if it's already running. */ if (xenstored_ready) goto out_err; gnttab_grant_foreign_access_ref(GNTTAB_RESERVED_XENSTORE, domid, virt_to_gfn(xen_store_interface), 0 /* writable */); arg.dom = DOMID_SELF; arg.remote_dom = domid; err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &arg); if (err) goto out_err; if (xen_store_evtchn > 0) xb_deinit_comms(); xen_store_evtchn = arg.port; xs_resume(); return arg.port; out_err: xs_suspend_cancel(); return err; } static long xenbus_backend_ioctl(struct file *file, unsigned int cmd, unsigned long data) { if (!capable(CAP_SYS_ADMIN)) return -EPERM; switch (cmd) { case IOCTL_XENBUS_BACKEND_EVTCHN: if (xen_store_evtchn > 0) return xen_store_evtchn; return -ENODEV; case IOCTL_XENBUS_BACKEND_SETUP: return xenbus_alloc(data); default: return -ENOTTY; } } static int xenbus_backend_mmap(struct file *file, struct vm_area_struct *vma) { size_t size = vma->vm_end - vma->vm_start; if (!capable(CAP_SYS_ADMIN)) return -EPERM; if ((size > PAGE_SIZE) || (vma->vm_pgoff != 0)) return -EINVAL; if (remap_pfn_range(vma, vma->vm_start, virt_to_pfn(xen_store_interface), size, vma->vm_page_prot)) return -EAGAIN; return 0; } static const struct file_operations xenbus_backend_fops = { .open = xenbus_backend_open, .mmap = xenbus_backend_mmap, .unlocked_ioctl = xenbus_backend_ioctl, }; static struct miscdevice xenbus_backend_dev = { .minor = MISC_DYNAMIC_MINOR, .name = "xen/xenbus_backend", .fops = &xenbus_backend_fops, }; static int __init xenbus_backend_init(void) { int err; if (!xen_initial_domain()) return -ENODEV; err = misc_register(&xenbus_backend_dev); if (err) pr_err("Could not register xenbus backend device\n"); return err; } device_initcall(xenbus_backend_init); remove&id=1b011e2f13fcf37e1e577fed25b295808d6c83b9'>net/6lowpan/ndisc.c
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authorJiri Slaby <jslaby@suse.cz>2016-12-19 16:23:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-20 09:48:47 -0800
commit1b011e2f13fcf37e1e577fed25b295808d6c83b9 (patch)
tree50bb2b58757f3c578f40dec19c2b42a8d6bc534d /net/6lowpan/ndisc.c
parent4983f0ab7ffaad1e534b21975367429736475205 (diff)
ratelimit: fix WARN_ON_RATELIMIT return value
The macro is to be used similarly as WARN_ON as: if (WARN_ON_RATELIMIT(condition, state)) do_something(); One would expect only 'condition' to affect the 'if', but WARN_ON_RATELIMIT does internally only: WARN_ON((condition) && __ratelimit(state)) So the 'if' is affected by the ratelimiting state too. Fix this by returning 'condition' in any case. Note that nobody uses WARN_ON_RATELIMIT yet, so there is nothing to worry about. But I was about to use it and was a bit surprised. Link: http://lkml.kernel.org/r/20161215093224.23126-1-jslaby@suse.cz Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/6lowpan/ndisc.c')