| Message ID | 20230720155902.1590362-5-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rtc devices: Avoid putting time_t in 32-bit variables | expand |
On 20/7/23 17:59, Peter Maydell wrote: > The functions qemu_get_timedate() and qemu_timedate_diff() take > and return a time offset as an integer. Coverity points out that > means that when an RTC device implementation holds an offset > as a time_t, as the m48t59 does, the time_t will get truncated. > (CID 1507157, 1517772). > > The functions work with time_t internally, so make them use that type > in their APIs. > > Note that this won't help any Y2038 issues where either the device > model itself is keeping the offset in a 32-bit integer, or where the > hardware under emulation has Y2038 or other rollover problems. If we > missed any cases of the former then hopefully Coverity will warn us > about them since after this patch we'd be truncating a time_t in > assignments from qemu_timedate_diff().) > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > include/sysemu/rtc.h | 4 ++-- > softmmu/rtc.c | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff --git a/include/sysemu/rtc.h b/include/sysemu/rtc.h index 159702b45b5..0fc8ad6fdf1 100644 --- a/include/sysemu/rtc.h +++ b/include/sysemu/rtc.h @@ -42,7 +42,7 @@ * The behaviour of the clock whose value this function returns will * depend on the -rtc command line option passed by the user. */ -void qemu_get_timedate(struct tm *tm, int offset); +void qemu_get_timedate(struct tm *tm, time_t offset); /** * qemu_timedate_diff: Return difference between a struct tm and the RTC @@ -53,6 +53,6 @@ void qemu_get_timedate(struct tm *tm, int offset); * a timestamp one hour further ahead than the current RTC time * then this function will return 3600. */ -int qemu_timedate_diff(struct tm *tm); +time_t qemu_timedate_diff(struct tm *tm); #endif diff --git a/softmmu/rtc.c b/softmmu/rtc.c index 4b2bf75dd67..4904581abeb 100644 --- a/softmmu/rtc.c +++ b/softmmu/rtc.c @@ -68,7 +68,7 @@ static time_t qemu_ref_timedate(QEMUClockType clock) return value; } -void qemu_get_timedate(struct tm *tm, int offset) +void qemu_get_timedate(struct tm *tm, time_t offset) { time_t ti = qemu_ref_timedate(rtc_clock); @@ -85,7 +85,7 @@ void qemu_get_timedate(struct tm *tm, int offset) } } -int qemu_timedate_diff(struct tm *tm) +time_t qemu_timedate_diff(struct tm *tm) { time_t seconds;
The functions qemu_get_timedate() and qemu_timedate_diff() take and return a time offset as an integer. Coverity points out that means that when an RTC device implementation holds an offset as a time_t, as the m48t59 does, the time_t will get truncated. (CID 1507157, 1517772). The functions work with time_t internally, so make them use that type in their APIs. Note that this won't help any Y2038 issues where either the device model itself is keeping the offset in a 32-bit integer, or where the hardware under emulation has Y2038 or other rollover problems. If we missed any cases of the former then hopefully Coverity will warn us about them since after this patch we'd be truncating a time_t in assignments from qemu_timedate_diff().) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- include/sysemu/rtc.h | 4 ++-- softmmu/rtc.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)