[Qemu-devel] [PULL 03/28] target/lm32: avoid integer overflow in next_page PC check

[Richard Henderson <richard.henderson@linaro.org>]

From: "Emilio G. Cota" <cota@braap.org>

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>
Acked-by: Michael Walle <michael@walle.cc>
Cc: Michael Walle <michael@walle.cc>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/lm32/translate.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/lm32/translate.c b/target/lm32/translate.c
index 2e1c5e6d01..fdd206a860 100644
--- a/target/lm32/translate.c
+++ b/target/lm32/translate.c
@@ -1055,7 +1055,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb)
     LM32CPU *cpu = lm32_env_get_cpu(env);
     struct DisasContext ctx, *dc = &ctx;
     uint32_t pc_start;
-    uint32_t next_page_start;
+    uint32_t page_start;
     int num_insns;
     int max_insns;
 
@@ -1075,7 +1075,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb)
         pc_start &= ~3;
     }
 
-    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) {
@@ -1115,7 +1115,7 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb)
          && !tcg_op_buf_full()
          && !cs->singlestep_enabled
          && !singlestep
-         && (dc->pc < next_page_start)
+         && (dc->pc - page_start < TARGET_PAGE_SIZE)
          && num_insns < max_insns);
 
     if (tb_cflags(tb) & CF_LAST_IO) {
-- 
2.17.0