From 99ab4d500af638ba3ebb20e8aa89d72201b70860 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Fri, 3 Feb 2023 18:15:10 +0100 Subject: [PATCH] accel/tcg: Test CPUJumpCache in tb_jmp_cache_clear_page After commit 4e4fa6c12d ("accel/tcg: Complete cpu initialization before registration"), it looks the CPUJumpCache pointer can be NULL. This causes a SIGSEV when running debug-wp-migration kvm unit test. At the first place it should be clarified why this TCG code is called with KVM acceleration. This may hide another bug. Fixes: 4e4fa6c12d ("accel/tcg: Complete cpu initialization before registration") Signed-off-by: Eric Auger Message-Id: <20230203171510.2867451-1-eric.auger@redhat.com> Signed-off-by: Richard Henderson --- accel/tcg/cputlb.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c index 4e040a1cb9..04e270742e 100644 --- a/accel/tcg/cputlb.c +++ b/accel/tcg/cputlb.c @@ -100,9 +100,14 @@ static void tlb_window_reset(CPUTLBDesc *desc, int64_t ns, static void tb_jmp_cache_clear_page(CPUState *cpu, target_ulong page_addr) { - int i, i0 = tb_jmp_cache_hash_page(page_addr); CPUJumpCache *jc = cpu->tb_jmp_cache; + int i, i0; + if (unlikely(!jc)) { + return; + } + + i0 = tb_jmp_cache_hash_page(page_addr); for (i = 0; i < TB_JMP_PAGE_SIZE; i++) { qatomic_set(&jc->array[i0 + i].tb, NULL); }