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authorDavid S. Miller <davem@davemloft.net>2015-09-27 01:08:27 +0200
committerDavid S. Miller <davem@davemloft.net>2015-09-27 01:08:27 +0200
commit4963ed48f2c20196d51a447ee87dc2815584fee4 (patch)
treea1902f466dafa00453889a4f1e66b00249ce0529 /arch/arm/xen/hypercall.S
parentMerge branch 'listener-sock-const' (diff)
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff)
downloadlinux-4963ed48f2c20196d51a447ee87dc2815584fee4.tar.xz
linux-4963ed48f2c20196d51a447ee87dc2815584fee4.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: net/ipv4/arp.c The net/ipv4/arp.c conflict was one commit adding a new local variable while another commit was deleting one. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/arm/xen/hypercall.S')
-rw-r--r--arch/arm/xen/hypercall.S15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
index f00e08075938..10fd99c568c6 100644
--- a/arch/arm/xen/hypercall.S
+++ b/arch/arm/xen/hypercall.S
@@ -98,8 +98,23 @@ ENTRY(privcmd_call)
mov r1, r2
mov r2, r3
ldr r3, [sp, #8]
+ /*
+ * Privcmd calls are issued by the userspace. We need to allow the
+ * kernel to access the userspace memory before issuing the hypercall.
+ */
+ uaccess_enable r4
+
+ /* r4 is loaded now as we use it as scratch register before */
ldr r4, [sp, #4]
__HVC(XEN_IMM)
+
+ /*
+ * Disable userspace access from kernel. This is fine to do it
+ * unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is
+ * called before.
+ */
+ uaccess_disable r4
+
ldm sp!, {r4}
ret lr
ENDPROC(privcmd_call);