[Qemu-devel] [PATCH 07/10] target/microblaze: avoid integer overflow in next_page PC check

["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.

Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
---
 target/microblaze/translate.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index 7628b0e..401dbe6 100644
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -1637,7 +1637,7 @@ 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;
@@ -1663,7 +1663,7 @@ 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) {
@@ -1749,7 +1749,7 @@ 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;
-- 
2.7.4