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authorJan Beulich <jbeulich@suse.com>2012-10-19 15:25:37 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-11-04 10:40:42 -0500
commitcf47a83fb06e42ae1b572ed68326068c7feaceae (patch)
tree52e694ac8adfc67d8dc82e35e046c14f0ceb10c2 /drivers/xen/Makefile
parent95a7d76897c1e7243d4137037c66d15cbf2cce76 (diff)
downloadlinux-cf47a83fb06e42ae1b572ed68326068c7feaceae.tar.bz2
xen/hypercall: fix hypercall fallback code for very old hypervisors
While copying the argument structures in HYPERVISOR_event_channel_op() and HYPERVISOR_physdev_op() into the local variable is sufficiently safe even if the actual structure is smaller than the container one, copying back eventual output values the same way isn't: This may collide with on-stack variables (particularly "rc") which may change between the first and second memcpy() (i.e. the second memcpy() could discard that change). Move the fallback code into out-of-line functions, and handle all of the operations known by this old a hypervisor individually: Some don't require copying back anything at all, and for the rest use the individual argument structures' sizes rather than the container's. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> [v2: Reduce #define/#undef usage in HYPERVISOR_physdev_op_compat().] [v3: Fix compile errors when modules use said hypercalls] [v4: Add xen_ prefix to the HYPERCALL_..] [v5: Alter the name and only EXPORT_SYMBOL_GPL one of them] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen/Makefile')
-rw-r--r--drivers/xen/Makefile2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 0e8637035457..46de6cdfccb3 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -2,7 +2,7 @@ ifneq ($(CONFIG_ARM),y)
obj-y += manage.o balloon.o
obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
endif
-obj-y += grant-table.o features.o events.o
+obj-y += grant-table.o features.o events.o fallback.o
obj-y += xenbus/
nostackp := $(call cc-option, -fno-stack-protector)