Re: [Qemu-devel] [PATCH 03/10] target/lm32: avoid integer overflow in next_page PC check

[Michael Walle]

Am 2018-04-10 18:19, schrieb Emilio G. Cota:

If the PC is in the last page of the address space, next_page_start
overflows to 0. Fix it.

Cc: Michael Walle 
Signed-off-by: Emilio G. Cota 


Acked-by: Michael Walle 

[Qemu-devel] [PATCH 03/10] target/lm32: avoid integer overflow in next_page PC check

[Emilio G. Cota]

If the PC is in the last page of the address space, next_page_start
overflows to 0. Fix it.

Cc: Michael Walle 
Signed-off-by: Emilio G. Cota 
---
 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 2e1c5e6..fdd206a 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 = 
 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) {
-- 
2.7.4