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| author | Sean Christopherson <seanjc@google.com> | 2022-12-09 21:55:44 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-27 12:00:49 +0100 |
| commit | 2f5213b8fc311eaa8fc78de7ecbd27ead027993c (patch) | |
| tree | 60701f5f9e1cc956a56bd51dd0969c498b9f037d /tools | |
| parent | KVM: selftests: Disable "gnu-variable-sized-type-not-at-end" warning (diff) | |
| download | linux-2f5213b8fc311eaa8fc78de7ecbd27ead027993c.tar.xz linux-2f5213b8fc311eaa8fc78de7ecbd27ead027993c.zip | |
KVM: selftests: Use magic value to signal ucall_alloc() failure
Use a magic value to signal a ucall_alloc() failure instead of simply
doing GUEST_ASSERT(). GUEST_ASSERT() relies on ucall_alloc() and so a
failure puts the guest into an infinite loop.
Use -1 as the magic value, as a real ucall struct should never wrap.
Reported-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/kvm/lib/ucall_common.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/tools/testing/selftests/kvm/lib/ucall_common.c b/tools/testing/selftests/kvm/lib/ucall_common.c index 0cc0971ce60e..2f0e2ea941cc 100644 --- a/tools/testing/selftests/kvm/lib/ucall_common.c +++ b/tools/testing/selftests/kvm/lib/ucall_common.c @@ -4,6 +4,8 @@ #include "linux/bitmap.h" #include "linux/atomic.h" +#define GUEST_UCALL_FAILED -1 + struct ucall_header { DECLARE_BITMAP(in_use, KVM_MAX_VCPUS); struct ucall ucalls[KVM_MAX_VCPUS]; @@ -41,7 +43,8 @@ static struct ucall *ucall_alloc(void) struct ucall *uc; int i; - GUEST_ASSERT(ucall_pool); + if (!ucall_pool) + goto ucall_failed; for (i = 0; i < KVM_MAX_VCPUS; ++i) { if (!test_and_set_bit(i, ucall_pool->in_use)) { @@ -51,7 +54,13 @@ static struct ucall *ucall_alloc(void) } } - GUEST_ASSERT(0); +ucall_failed: + /* + * If the vCPU cannot grab a ucall structure, make a bare ucall with a + * magic value to signal to get_ucall() that things went sideways. + * GUEST_ASSERT() depends on ucall_alloc() and so cannot be used here. + */ + ucall_arch_do_ucall(GUEST_UCALL_FAILED); return NULL; } @@ -93,6 +102,9 @@ uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) addr = ucall_arch_get_ucall(vcpu); if (addr) { + TEST_ASSERT(addr != (void *)GUEST_UCALL_FAILED, + "Guest failed to allocate ucall struct"); + memcpy(uc, addr, sizeof(*uc)); vcpu_run_complete_io(vcpu); } else { |