diff options
| author | Jan Beulich <jbeulich@suse.com> | 2012-10-19 15:25:37 -0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-11-04 10:40:42 -0500 |
| commit | cf47a83fb06e42ae1b572ed68326068c7feaceae (patch) | |
| tree | 52e694ac8adfc67d8dc82e35e046c14f0ceb10c2 /drivers/xen/Makefile | |
| parent | 95a7d76897c1e7243d4137037c66d15cbf2cce76 (diff) | |
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/Makefile | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 0e863703545..46de6cdfccb 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) |