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| author | Christian Borntraeger <borntraeger@linux.ibm.com> | 2026-08-05 13:04:53 +0200 |
|---|---|---|
| committer | Claudio Imbrenda <imbrenda@linux.ibm.com> | 2026-08-11 10:45:27 +0200 |
| commit | a4e482def8533ebace517d9f67f1465841b1f982 (patch) | |
| tree | 83812fce51c680ca2f361f7af76143b9b93f07ea | |
| parent | aa9c8e8baf1e765fa65b93212522c636f25d846f (diff) | |
| download | linux-a4e482def8533ebace517d9f67f1465841b1f982.tar.gz linux-a4e482def8533ebace517d9f67f1465841b1f982.zip | |
KVM: s390: Take srcu when importing watchpoint data
__import_wp_info() backs up the original guest memory contents of a
watchpoint with read_guest_abs(), which is kvm_read_guest() and therefore
resolves the memslot via __kvm_memslots(). That requires kvm->srcu (or
kvm->slots_lock) to be held, otherwise a concurrent memslot update can
free the memslots array under us once its SRCU grace period has elapsed.
As this is not fast path, following lock ordering (mutex first, then
srcu) take the big hammer and hold the srcu for the full import.
Fixes: 27291e2165b6 ("KVM: s390: hardware support for guest debugging")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260805110455.7200-7-borntraeger@linux.ibm.com>
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 611dcb534210..0a197e055cad 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -4248,8 +4248,10 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, /* enforce guest PER */ kvm_s390_set_cpuflags(vcpu, CPUSTAT_P); - if (dbg->control & KVM_GUESTDBG_USE_HW_BP) - rc = kvm_s390_import_bp_data(vcpu, dbg); + if (dbg->control & KVM_GUESTDBG_USE_HW_BP) { + scoped_guard(srcu, &vcpu->kvm->srcu) + rc = kvm_s390_import_bp_data(vcpu, dbg); + } } else { kvm_s390_clear_cpuflags(vcpu, CPUSTAT_P); vcpu->arch.guestdbg.last_bp = 0; |