K 10
svn:author
V 3
dim
K 8
svn:date
V 27
2021-09-03T00:01:05.716873Z
K 7
svn:log
V 1337
xen: Fix warning by adding KERNBASE to modlist_paddr before casting

Clang 13 produces the following warning for hammer_time_xen():

sys/x86/xen/pv.c:183:19: error: the pointer incremented by -2147483648 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements) [-Werror,-Warray-bounds]
                    (vm_paddr_t)start_info->modlist_paddr + KERNBASE;
                                ^                               ~~~~~~~~
sys/xen/interface/arch-x86/hvm/start_info.h:131:5: note: array 'modlist_paddr' declared here
    uint64_t modlist_paddr;         /* Physical address of an array of           */
    ^

This is because the expression first casts start_info->modlist_paddr to
struct hvm_modlist_entry * (via vmpaddr_t), and *then* adds KERNBASE,
which is then interpreted as KERNBASE * sizeof(struct
hvm_modlist_entry).

Instead, parenthesize the addition to get the intended result, and cast
it to struct hvm_modlist_entry * afterwards. Also remove the cast to
vmpaddr_t since it is not necessary.

Reviewed by:	royger
Differential Revision: https://reviews.freebsd.org/D31711

(cherry picked from commit 8e3c56d6b676a175e974bad4c20797fb35017db8)

Git Hash:   cc110974c4edae799e2682afcd32cbfc094e6237
Git Author: dim@FreeBSD.org
END