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authorPeter Maydell <peter.maydell@linaro.org>2015-02-13 05:46:09 +0000
committerPeter Maydell <peter.maydell@linaro.org>2015-02-13 05:46:09 +0000
commit037e1d009e2fcb80784d37f0e12aa999787d46d4 (patch)
treeb90a6ed279eede689b2a3965b9813e664c833cb0
parente167adc9d9f5df4f8109aecd4552c407fdce094a (diff)
target-arm: A64: Avoid left shifting negative integers in disas_pc_rel_addr
Shifting a negative integer left is undefined behaviour in C. Avoid it by assembling and shifting the offset fields as unsigned values and then sign extending as the final action. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1423233250-15853-4-git-send-email-peter.maydell@linaro.org
-rw-r--r--target-arm/translate-a64.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 94b3bf40f6..68c5b23914 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -2662,11 +2662,12 @@ static void disas_pc_rel_adr(DisasContext *s, uint32_t insn)
{
unsigned int page, rd;
uint64_t base;
- int64_t offset;
+ uint64_t offset;
page = extract32(insn, 31, 1);
/* SignExtend(immhi:immlo) -> offset */
- offset = ((int64_t)sextract32(insn, 5, 19) << 2) | extract32(insn, 29, 2);
+ offset = sextract64(insn, 5, 19);
+ offset = offset << 2 | extract32(insn, 29, 2);
rd = extract32(insn, 0, 5);
base = s->pc - 4;