Date: Sun, 29 Aug 2021 17:44:45 GMT From: Dimitry Andric <dim@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 8e3c56d6b676 - main - xen: Fix warning by adding KERNBASE to modlist_paddr before casting Message-ID: <202108291744.17THijbo007116@gitrepo.freebsd.org>
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The branch main has been updated by dim: URL: https://cgit.FreeBSD.org/src/commit/?id=8e3c56d6b676a175e974bad4c20797fb35017db8 commit 8e3c56d6b676a175e974bad4c20797fb35017db8 Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2021-08-29 14:02:31 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2021-08-29 17:43:00 +0000 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 MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D31711 --- sys/x86/xen/pv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c index 6e1bba691171..a316d4ee8857 100644 --- a/sys/x86/xen/pv.c +++ b/sys/x86/xen/pv.c @@ -180,7 +180,7 @@ hammer_time_xen(vm_paddr_t start_info_paddr) HYPERVISOR_shutdown(SHUTDOWN_crash); } mod = (struct hvm_modlist_entry *) - (vm_paddr_t)start_info->modlist_paddr + KERNBASE; + (start_info->modlist_paddr + KERNBASE); if (mod[0].paddr >= physfree) { xc_printf("ERROR: unexpected module memory address\n"); HYPERVISOR_shutdown(SHUTDOWN_crash);
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