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authorArnd Bergmann <arnd@arndb.de>2019-03-04 21:52:39 +0100
committerJuergen Gross <jgross@suse.com>2019-03-05 12:07:32 +0100
commitb1ddd406cd1e9bb51fa90d03ee562c832e38eb52 (patch)
tree01ada3c648984bced35c52dcca18c03df594e2f6 /drivers/xen/Makefile
parent85eb278c1899f78d1429b45ffa84039d9011cb55 (diff)
downloadlinux-b1ddd406cd1e9bb51fa90d03ee562c832e38eb52.tar.bz2
xen: remove pre-xen3 fallback handlers
The legacy hypercall handlers were originally added with a comment explaining that "copying the argument structures in HYPERVISOR_event_channel_op() and HYPERVISOR_physdev_op() into the local variable is sufficiently safe" and only made sure to not write past the end of the argument structure, the checks in linux/string.h disagree with that, when link-time optimizations are used: In function 'memcpy', inlined from 'pirq_query_unmask' at drivers/xen/fallback.c:53:2, inlined from '__startup_pirq' at drivers/xen/events/events_base.c:529:2, inlined from 'restore_pirqs' at drivers/xen/events/events_base.c:1439:3, inlined from 'xen_irq_resume' at drivers/xen/events/events_base.c:1581:2: include/linux/string.h:350:3: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter __read_overflow2(); ^ Further research turned out that only Xen 3.0.2 or earlier required the fallback at all, while all versions in use today don't need it. As far as I can tell, it is not even possible to run a mainline kernel on those old Xen releases, at the time when they were in use, only a patched kernel was supported anyway. Fixes: cf47a83fb06e ("xen/hypercall: fix hypercall fallback code for very old hypervisors") Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Jan Beulich <JBeulich@suse.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen/Makefile')
-rw-r--r--drivers/xen/Makefile1
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index c48927a58e10..ad3844d9f876 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -1,6 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
-obj-$(CONFIG_X86) += fallback.o
obj-y += grant-table.o features.o balloon.o manage.o preempt.o time.o
obj-y += mem-reservation.o
obj-y += events/