[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[qemu-s390x] [PATCH 09/10] target/s390x: avoid integer overflow in next_
From: |
Emilio G. Cota |
Subject: |
[qemu-s390x] [PATCH 09/10] target/s390x: avoid integer overflow in next_page PC check |
Date: |
Tue, 10 Apr 2018 12:19:45 -0400 |
If the PC is in the last page of the address space, next_page_start
overflows to 0. Fix it.
Cc: Cornelia Huck <address@hidden>
Cc: Alexander Graf <address@hidden>
Cc: David Hildenbrand <address@hidden>
Cc: address@hidden
Signed-off-by: Emilio G. Cota <address@hidden>
---
target/s390x/translate.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index 7d39ab3..44449f1 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -6163,7 +6163,7 @@ void gen_intermediate_code(CPUState *cs, struct
TranslationBlock *tb)
CPUS390XState *env = cs->env_ptr;
DisasContext dc;
target_ulong pc_start;
- uint64_t next_page_start;
+ uint64_t page_start;
int num_insns, max_insns;
ExitStatus status;
bool do_debug;
@@ -6181,7 +6181,7 @@ void gen_intermediate_code(CPUState *cs, struct
TranslationBlock *tb)
dc.ex_value = tb->cs_base;
do_debug = dc.singlestep_enabled = cs->singlestep_enabled;
- 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;
@@ -6218,7 +6218,7 @@ void gen_intermediate_code(CPUState *cs, struct
TranslationBlock *tb)
/* If we reach a page boundary, are single stepping,
or exhaust instruction count, stop generation. */
if (status == NO_EXIT
- && (dc.pc >= next_page_start
+ && (dc.pc - page_start >= TARGET_PAGE_SIZE
|| tcg_op_buf_full()
|| num_insns >= max_insns
|| singlestep
--
2.7.4