target/microblaze: 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 <richard.henderson@linaro.org>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Emilio G. Cota 2018-04-10 10:47:51 -04:00 committed by Richard Henderson
parent 5c433a7aac
commit 56371527f3

View File

@ -1635,7 +1635,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb)
uint32_t pc_start;
struct DisasContext ctx;
struct DisasContext *dc = &ctx;
uint32_t next_page_start, org_flags;
uint32_t page_start, org_flags;
target_ulong npc;
int num_insns;
int max_insns;
@ -1661,7 +1661,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb)
cpu_abort(cs, "Microblaze: unaligned PC=%x\n", pc_start);
}
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;
if (max_insns == 0) {
@ -1747,7 +1747,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb)
} while (!dc->is_jmp && !dc->cpustate_changed
&& !tcg_op_buf_full()
&& !singlestep
&& (dc->pc < next_page_start)
&& (dc->pc - page_start < TARGET_PAGE_SIZE)
&& num_insns < max_insns);
npc = dc->pc;