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| author | Arnd Bergmann <arnd@arndb.de> | 2019-03-04 21:52:39 +0100 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2019-03-05 12:07:32 +0100 |
| commit | b1ddd406cd1e9bb51fa90d03ee562c832e38eb52 (patch) | |
| tree | 01ada3c648984bced35c52dcca18c03df594e2f6 /drivers/xen/Makefile | |
| parent | 85eb278c1899f78d1429b45ffa84039d9011cb55 (diff) | |
| download | linux-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/Makefile | 1 |
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/ |