xen/kexec: remove spinlock now that all KEXEC hypercall ops are protected at the...

The spinlock in kexec_swap_images() was removed as
this function is only reachable on the kexec hypercall, which is
now protected at the top-level in do_kexec_op_internal(),
thus the local spinlock is no longer necessary.

Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Bhavesh Davda <bhavesh.davda@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Release-acked-by: Julien Grall <julien.grall@arm.com>

diff --git a/xen/common/kexec.c b/xen/common/kexec.c
index d6568e3bc6c87725bdd4cc990a462d165b6e16ac..fbca8a6499a7944f22ed093cba6e8f66001248d9 100644 (file)
--- a/xen/common/kexec.c
+++ b/xen/common/kexec.c
@@ -820,7 +820,6 @@ static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg)
 static int kexec_swap_images(int type, struct kexec_image *new,
                              struct kexec_image **old)
 {
-    static DEFINE_SPINLOCK(kexec_lock);
     int base, bit, pos;
     int new_slot, old_slot;
 
@@ -832,7 +831,7 @@ static int kexec_swap_images(int type, struct kexec_image *new,
     if ( kexec_load_get_bits(type, &base, &bit) )
         return -EINVAL;
 
-    spin_lock(&kexec_lock);
+    ASSERT(test_bit(KEXEC_FLAG_IN_HYPERCALL, &kexec_flags));
 
     pos = (test_bit(bit, &kexec_flags) != 0);
     old_slot = base + pos;
@@ -846,8 +845,6 @@ static int kexec_swap_images(int type, struct kexec_image *new,
     clear_bit(old_slot, &kexec_flags);
     *old = kexec_image[old_slot];
 
-    spin_unlock(&kexec_lock);
-
     return 0;
 }