From 2e3883d03df167b15f2acc5345eb9a7e0150a062 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 3 Mar 2017 15:50:30 +0000 Subject: disas/m68k: Avoid unintended sign extension in get_field() In get_field(), we take an 'unsigned char' value and shift it left, which implicitly promotes it to 'signed int', before ORing it into an 'unsigned long' type. If 'unsigned long' is 64 bits then this will result in a sign extension and the top 32 bits of the result will be 1s. Add explicit casts to unsigned long before shifting to prevent this. (Spotted by Coverity, CID 715697.) Signed-off-by: Peter Maydell Reviewed-by: Laurent Vivier Message-id: 1488556233-31246-4-git-send-email-peter.maydell@linaro.org --- disas/m68k.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'disas') diff --git a/disas/m68k.c b/disas/m68k.c index 073abb9efd..61b689ef3e 100644 --- a/disas/m68k.c +++ b/disas/m68k.c @@ -4685,10 +4685,11 @@ get_field (const unsigned char *data, enum floatformat_byteorders order, /* This is the last byte; zero out the bits which are not part of this field. */ result |= - (*(data + cur_byte) & ((1 << (len - cur_bitshift)) - 1)) + (unsigned long)(*(data + cur_byte) + & ((1 << (len - cur_bitshift)) - 1)) << cur_bitshift; else - result |= *(data + cur_byte) << cur_bitshift; + result |= (unsigned long)*(data + cur_byte) << cur_bitshift; cur_bitshift += FLOATFORMAT_CHAR_BIT; if (order == floatformat_little) ++cur_byte; -- cgit v1.2.1