diff options
| author | Vincent Donnefort <vdonnefort@google.com> | 2026-05-21 13:46:12 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2026-05-27 14:07:24 +0100 |
| commit | a23780ea9db3f3cadbb52ff6151384bff89d95d2 (patch) | |
| tree | c8c713074cdd96939327303620dd43a769e2853a | |
| parent | 0f7abb6eaa3c3965f925e231c18409dac4f5a0c1 (diff) | |
KVM: arm64: Fix rollback in hyp_trace_buffer_share_hyp()
When sharing the trace buffer with the hypervisor, if sharing a page
fails, the rollback path in hyp_trace_buffer_share_hyp() misses
unsharing the metadata page (meta_va) which was successfully shared
before entering the page sharing loop.
Additionally, if a failure occurs, the cleanup calls
hyp_trace_buffer_unshare_hyp() with an incorrect CPU index. Since that
CPU's pages were already rolled back locally in the loop, this leads to
duplicate unsharing attempts.
Fix both issues affecting the rollback.
Fixes: 3aed038aac8d ("KVM: arm64: Add trace remote for the nVHE/pKVM hyp")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260521124613.911067-3-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
| -rw-r--r-- | arch/arm64/kvm/hyp_trace.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c index 06805b426101..8595f9bdb3dc 100644 --- a/arch/arm64/kvm/hyp_trace.c +++ b/arch/arm64/kvm/hyp_trace.c @@ -212,14 +212,15 @@ static int hyp_trace_buffer_share_hyp(struct hyp_trace_buffer *trace_buffer) } if (ret) { - for (p--; p >= 0; p--) + while (--p >= 0) __unshare_page(rb_desc->page_va[p]); + __unshare_page(rb_desc->meta_va); break; } } if (ret) - hyp_trace_buffer_unshare_hyp(trace_buffer, cpu--); + hyp_trace_buffer_unshare_hyp(trace_buffer, --cpu); return ret; } |