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authorzec <zec@FreeBSD.org>2009-05-05 10:56:12 +0000
committerzec <zec@FreeBSD.org>2009-05-05 10:56:12 +0000
commitd78a1b1a824c4f5eb8cb3583bb5265f73dcc24dd (patch)
tree79a0bccccf2c92504cdf23ad15f7c1813bb3f926 /sys/kern/kern_linker.c
parent8e4ffe653f6c9ff6da3eed58566ef35e77d530d0 (diff)
downloadFreeBSD-src-d78a1b1a824c4f5eb8cb3583bb5265f73dcc24dd.zip
FreeBSD-src-d78a1b1a824c4f5eb8cb3583bb5265f73dcc24dd.tar.gz
Change the curvnet variable from a global const struct vnet *,
previously always pointing to the default vnet context, to a dynamically changing thread-local one. The currvnet context should be set on entry to networking code via CURVNET_SET() macros, and reverted to previous state via CURVNET_RESTORE(). Recursions on curvnet are permitted, though strongly discuouraged. This change should have no functional impact on nooptions VIMAGE kernel builds, where CURVNET_* macros expand to whitespace. The curthread->td_vnet (aka curvnet) variable's purpose is to be an indicator of the vnet context in which the current network-related operation takes place, in case we cannot deduce the current vnet context from any other source, such as by looking at mbuf's m->m_pkthdr.rcvif->if_vnet, sockets's so->so_vnet etc. Moreover, so far curvnet has turned out to be an invaluable consistency checking aid: it helps to catch cases when sockets, ifnets or any other vnet-aware structures may have leaked from one vnet to another. The exact placement of the CURVNET_SET() / CURVNET_RESTORE() macros was a result of an empirical iterative process, whith an aim to reduce recursions on CURVNET_SET() to a minimum, while still reducing the scope of CURVNET_SET() to networking only operations - the alternative would be calling CURVNET_SET() on each system call entry. In general, curvnet has to be set in three typicall cases: when processing socket-related requests from userspace or from within the kernel; when processing inbound traffic flowing from device drivers to upper layers of the networking stack, and when executing timer-driven networking functions. This change also introduces a DDB subcommand to show the list of all vnet instances. Approved by: julian (mentor)
Diffstat (limited to 'sys/kern/kern_linker.c')
-rw-r--r--sys/kern/kern_linker.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/sys/kern/kern_linker.c b/sys/kern/kern_linker.c
index 9350713..2237107 100644
--- a/sys/kern/kern_linker.c
+++ b/sys/kern/kern_linker.c
@@ -993,6 +993,12 @@ kern_kldload(struct thread *td, const char *file, int *fileid)
return (error);
/*
+ * It's possible that kldloaded module will attach a new ifnet,
+ * so vnet context must be set when this ocurs.
+ */
+ CURVNET_SET(TD_TO_VNET(td));
+
+ /*
* If file does not contain a qualified name or any dot in it
* (kldname.ko, or kldname.ver.ko) treat it as an interface
* name.
@@ -1019,6 +1025,7 @@ kern_kldload(struct thread *td, const char *file, int *fileid)
*fileid = lf->id;
unlock:
KLD_UNLOCK();
+ CURVNET_RESTORE();
return (error);
}
@@ -1056,6 +1063,7 @@ kern_kldunload(struct thread *td, int fileid, int flags)
if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
return (error);
+ CURVNET_SET(TD_TO_VNET(td));
KLD_LOCK();
lf = linker_find_file_by_id(fileid);
if (lf) {
@@ -1092,6 +1100,7 @@ kern_kldunload(struct thread *td, int fileid, int flags)
PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
#endif
KLD_UNLOCK();
+ CURVNET_RESTORE();
return (error);
}
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