| Message ID | 20180611171007.4165-3-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add ldn_*_p() and stn_*_p() and use them in exec.c | expand |
On 06/11/2018 07:10 AM, Peter Maydell wrote: > In subpage_read() we perform a load of the data into a local buffer > which we then access using ldub_p(), lduw_p(), ldl_p() or ldq_p() > depending on its size, storing the result into the uint64_t *data. > Since ldl_p() returns an 'int', this means that for the 4-byte > case we will sign-extend the data, whereas for 1 and 2 byte > reads we zero-extend it. > > This ought not to matter since the caller will likely ignore values in > the high bytes of the data, but add a cast so that we're consistent. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/exec.c b/exec.c index 9cbba6adcd3..90b47cde7b1 100644 --- a/exec.c +++ b/exec.c @@ -2747,7 +2747,7 @@ static MemTxResult subpage_read(void *opaque, hwaddr addr, uint64_t *data, *data = lduw_p(buf); return MEMTX_OK; case 4: - *data = ldl_p(buf); + *data = (uint32_t)ldl_p(buf); return MEMTX_OK; case 8: *data = ldq_p(buf);
In subpage_read() we perform a load of the data into a local buffer which we then access using ldub_p(), lduw_p(), ldl_p() or ldq_p() depending on its size, storing the result into the uint64_t *data. Since ldl_p() returns an 'int', this means that for the 4-byte case we will sign-extend the data, whereas for 1 and 2 byte reads we zero-extend it. This ought not to matter since the caller will likely ignore values in the high bytes of the data, but add a cast so that we're consistent. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.17.1