On Tue, Jun 18, 2024 at 1:37 PM Philippe Mathieu-Daudé <phi...@linaro.org> wrote:
> Hi Paul, > > On 18/6/24 20:58, Paul Zimmerman wrote: > > On Tue, Jun 18, 2024 at 6:56 AM Zheyu Ma <zheyum...@gmail.com > > <mailto:zheyum...@gmail.com>> wrote: > > > > > > This commit modifies the dwc2_hsotg_read() and dwc2_hsotg_write() > > functions > > > to handle invalid address access gracefully. Instead of using > > > g_assert_not_reached(), which causes the program to abort, the > functions > > > now log an error message and return a default value for reads or do > > > nothing for writes. > > > > > > This change prevents the program from aborting and provides clear log > > > messages indicating when an invalid memory address is accessed. > > > > > > Reproducer: > > > cat << EOF | qemu-system-aarch64 -display none \ > > > -machine accel=qtest, -m 512M -machine raspi2b -m 1G -nodefaults \ > > > -usb -drive file=null-co://,if=none,format=raw,id=disk0 -device \ > > > usb-storage,port=1,drive=disk0 -qtest stdio > > > readl 0x3f980dfb > > > EOF > > > > > > Signed-off-by: Zheyu Ma <zheyum...@gmail.com > > <mailto:zheyum...@gmail.com>> > > > --- > > > hw/usb/hcd-dwc2.c | 9 +++++++-- > > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > > > diff --git a/hw/usb/hcd-dwc2.c b/hw/usb/hcd-dwc2.c > > > index 8cac9c0a06..b4f0652c7d 100644 > > > --- a/hw/usb/hcd-dwc2.c > > > +++ b/hw/usb/hcd-dwc2.c > > > @@ -1128,7 +1128,10 @@ static uint64_t dwc2_hsotg_read(void *ptr, > hwaddr addr, unsigned size) > > > val = dwc2_pcgreg_read(ptr, addr, (addr - HSOTG_REG(0xe00)) > >> 2, size); > > > break; > > > default: > > > - g_assert_not_reached(); > > > + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset > 0x%"HWADDR_PRIx"\n", > > > + __func__, addr); > > > + val = 0; > > > + break; > > > } > > > > > > return val; > > > @@ -1160,7 +1163,9 @@ static void dwc2_hsotg_write(void *ptr, hwaddr > addr, uint64_t val, > > > dwc2_pcgreg_write(ptr, addr, (addr - HSOTG_REG(0xe00)) >> 2, > val, size); > > > break; > > > default: > > > - g_assert_not_reached(); > > > + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset > 0x%"HWADDR_PRIx"\n", > > > + __func__, addr); > > > + break; > > > } > > > } > > > > > > -- > > > 2.34.1 > > > > Looks good to me. > > > > Reviewed-by: Paul Zimmerman <pauld...@gmail.com <mailto: > pauld...@gmail.com>> > > > > Does that mean on real HW the access to unassigned registers are > silently ignored as RAZ/WI like this patch? (I don't have access > to the specs -- IIRC you don't neither, but you might have real > HW to test). Hi Phil, I have an old raspi around somewhere I could probably dig up and test with, but I'm not familiar with qtest, so I don't know how I would reproduce the failure on real hw. Besides, isn't it always better to fail and log an error than just crash? Regards, Paul
