Messages in this thread | | | From | Pawel Laszczak <> | Subject | RE: [PATCH] usb: cdnsp: Fix segmentation fault in cdns_lost_power function | Date | Wed, 12 Jan 2022 13:13:10 +0000 |
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> >On 22-01-11 10:07:37, Pawel Laszczak wrote: >> From: Pawel Laszczak <pawell@cadence.com> >> >> CDNSP driver read not initialized cdns->otg_v0_regs >> which lead to segmentation fault. Patch fixes this issue. >> >> Fixes: 2cf2581cd229 ("usb: cdns3: add power lost support for system resume") >> cc: <stable@vger.kernel.org> >> Signed-off-by: Pawel Laszczak <pawell@cadence.com> >> --- >> drivers/usb/cdns3/drd.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c >> index 55c73b1d8704..d00ff98dffab 100644 >> --- a/drivers/usb/cdns3/drd.c >> +++ b/drivers/usb/cdns3/drd.c >> @@ -483,11 +483,11 @@ int cdns_drd_exit(struct cdns *cdns) >> /* Indicate the cdns3 core was power lost before */ >> bool cdns_power_is_lost(struct cdns *cdns) >> { >> - if (cdns->version == CDNS3_CONTROLLER_V1) { >> - if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0))) >> + if (cdns->version == CDNS3_CONTROLLER_V0) { >> + if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0))) >> return true; >> } else { >> - if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0))) >> + if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0))) >> return true; >> } >> return false; >> -- > >Pawel, may this lead cdns driver segment fault? >
Yes, we can observe such situation for CDNSP driver on simulation. As you know, it is a common code and driver support two version of register map for DRD.
If cdns->version == CDNSP_CONTROLLER_V2 (for CNDSP) the cdns->otg_v0_regs is NULL. It will cause segmentation fault.
I didn't analyze why this issue was not observed on my FPGA testing board.
Regards,
Pawel Laszczak
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