From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46188) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f5vzs-0007Py-Tb for qemu-devel@nongnu.org; Tue, 10 Apr 2018 12:19:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f5vzq-000307-1x for qemu-devel@nongnu.org; Tue, 10 Apr 2018 12:19:52 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:44229) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f5vzp-0002yh-Tr for qemu-devel@nongnu.org; Tue, 10 Apr 2018 12:19:49 -0400 From: "Emilio G. Cota" Date: Tue, 10 Apr 2018 12:19:40 -0400 Message-Id: <1523377186-32578-5-git-send-email-cota@braap.org> In-Reply-To: <1523377186-32578-1-git-send-email-cota@braap.org> References: <1523377186-32578-1-git-send-email-cota@braap.org> Subject: [Qemu-devel] [PATCH 04/10] target/xtensa: avoid integer overflow in next_page PC check List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Richard Henderson , Max Filippov If the PC is in the last page of the address space, next_page_start overflows to 0. Fix it. Cc: Max Filippov Signed-off-by: Emilio G. Cota --- target/xtensa/translate.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c index 4f6d030..aad4963 100644 --- a/target/xtensa/translate.c +++ b/target/xtensa/translate.c @@ -1061,8 +1061,7 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb) int insn_count = 0; int max_insns = tb_cflags(tb) & CF_COUNT_MASK; uint32_t pc_start = tb->pc; - uint32_t next_page_start = - (pc_start & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE; + uint32_t page_start = pc_start & TARGET_PAGE_MASK; if (max_insns == 0) { max_insns = CF_COUNT_MASK; @@ -1162,9 +1161,9 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb) } } while (dc.is_jmp == DISAS_NEXT && insn_count < max_insns && - dc.pc < next_page_start && - dc.pc + xtensa_insn_len(env, &dc) <= next_page_start && - !tcg_op_buf_full()); + dc.pc - page_start < TARGET_PAGE_SIZE && + dc.pc - page_start + xtensa_insn_len(env, &dc) <= TARGET_PAGE_SIZE + && !tcg_op_buf_full()); done: reset_sar_tracker(&dc); if (dc.icount) { -- 2.7.4