From 071bd2b628cedbb640be8ca6c25d1949b2e6fe4a Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Tue, 10 Apr 2018 11:12:26 -0400 Subject: target/s390x: avoid integer overflow in next_page PC check If the PC is in the last page of the address space, next_page_start overflows to 0. Fix it. Reviewed-by: Richard Henderson Reviewed-by: Thomas Huth Reviewed-by: David Hildenbrand Acked-by: Cornelia Huck Cc: Cornelia Huck Cc: Alexander Graf Cc: David Hildenbrand Cc: qemu-s390x@nongnu.org Signed-off-by: Emilio G. Cota Signed-off-by: Richard Henderson --- target/s390x/translate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/target/s390x/translate.c b/target/s390x/translate.c index 7d39ab350d..44449f11ab 100644 --- a/target/s390x/translate.c +++ b/target/s390x/translate.c @@ -6163,7 +6163,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb) CPUS390XState *env = cs->env_ptr; DisasContext dc; target_ulong pc_start; - uint64_t next_page_start; + uint64_t page_start; int num_insns, max_insns; ExitStatus status; bool do_debug; @@ -6181,7 +6181,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb) dc.ex_value = tb->cs_base; do_debug = dc.singlestep_enabled = cs->singlestep_enabled; - next_page_start = (pc_start & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE; + page_start = pc_start & TARGET_PAGE_MASK; num_insns = 0; max_insns = tb_cflags(tb) & CF_COUNT_MASK; @@ -6218,7 +6218,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb) /* If we reach a page boundary, are single stepping, or exhaust instruction count, stop generation. */ if (status == NO_EXIT - && (dc.pc >= next_page_start + && (dc.pc - page_start >= TARGET_PAGE_SIZE || tcg_op_buf_full() || num_insns >= max_insns || singlestep -- cgit v1.2.1