On 21-11-02 03:59:16, 胡启航(Nick Hu) wrote:
> From 9b8262792b6e85e6060601dbfc651b1e75b649f0 Mon Sep 17 00:00:00 2001
> From: Qihang Hu <huqihang@xxxxxxxx>
> Date: Sat, 30 Oct 2021 16:11:38 +0800
> Subject: [PATCH] usb: gadget: composite: Fix null pointer exception
>
> In the config_ep_by_speed_and_alt function, select the corresponding
> descriptor through g->speed, but the function driver may not
> support the corresponding speed. So, we need to check whether the
> function driver provides the corresponding speed descriptor when
> selecting the descriptor.
>
> [ 237.708146] android_work: sent uevent USB_STATE=CONNECTED
> [ 237.712464] kconfigfs-gadget gadget: super-speed config #1: b
> [ 237.712487] kUnable to handle kernel NULL pointer dereference at virtual address 0000000000000000
> [ 237.712493] kMem abort info:
> [ 237.712498] k ESR = 0x96000006
> [ 237.712504] k EC = 0x25: DABT (current EL), IL = 32 bits
> [ 237.712510] k SET = 0, FnV = 0
> [ 237.712515] k EA = 0, S1PTW = 0
> [ 237.712520] kData abort info:
> [ 237.712525] k ISV = 0, ISS = 0x00000006
> [ 237.712530] k CM = 0, WnR = 0
> [ 237.712536] kuser pgtable: 4k pages, 39-bit VAs, pgdp=000000020ef29000
> [ 237.712541] k[0000000000000000] pgd=000000020ef2a003, pud=000000020ef2a003, pmd=0000000000000000
> [ 237.712554] kInternal error: Oops: 96000006 [#1] PREEMPT SMP
> [ 237.722067] kSkip md ftrace buffer dump for: 0x1609e0
> [ 237.787037] kWorkqueue: dwc_wq dwc3_bh_work.cfi_jt
> [ 237.854922] kpstate: 60c00085 (nZCv daIf +PAN +UAO)
> [ 237.863165] kpc : config_ep_by_speed_and_alt+0x90/0x308
> [ 237.871766] klr : audio_set_alt+0x54/0x78
> [ 237.879108] ksp : ffffffc0104839e0
>
> Signed-off-by: Qihang Hu <huqihang@xxxxxxxx>
> ---
> drivers/usb/gadget/composite.c | 39 ++++++++++++++++++++++------------
> 1 file changed, 26 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index 72a9797dbbae..4f0d81f561ae 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -151,9 +151,11 @@ int config_ep_by_speed_and_alt(struct usb_gadget *g,
> struct usb_ep *_ep,
> u8 alt)
> {
> + struct usb_composite_dev *cdev;
For newly added variable definition, you could add it at the last existing
variable definition, see position "..." below.
> struct usb_endpoint_descriptor *chosen_desc = NULL;
> struct usb_interface_descriptor *int_desc = NULL;
> struct usb_descriptor_header **speed_desc = NULL;
...
> + int incomplete_desc = 0;
>
> struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
> int want_comp_desc = 0;
> @@ -167,28 +169,43 @@ int config_ep_by_speed_and_alt(struct usb_gadget *g,
> switch (g->speed) {
> case USB_SPEED_SUPER_PLUS:
> if (gadget_is_superspeed_plus(g)) {
> - speed_desc = f->ssp_descriptors;
> - want_comp_desc = 1;
> - break;
> + if (f->ssp_descriptors) {
> + speed_desc = f->ssp_descriptors;
> + want_comp_desc = 1;
> + break;
> + }
> + incomplete_desc = 1;
> }
> fallthrough;
> case USB_SPEED_SUPER:
> if (gadget_is_superspeed(g)) {
> - speed_desc = f->ss_descriptors;
> - want_comp_desc = 1;
> - break;
> + if (f->ss_descriptors) {
> + speed_desc = f->ss_descriptors;
> + want_comp_desc = 1;
> + break;
> + }
> + incomplete_desc = 1;
> }
> fallthrough;
> case USB_SPEED_HIGH:
> if (gadget_is_dualspeed(g)) {
> - speed_desc = f->hs_descriptors;
> - break;
> + if (f->hs_descriptors) {
> + speed_desc = f->hs_descriptors;
> + break;
> + }
> + incomplete_desc = 1;
> }
> fallthrough;
> default:
> speed_desc = f->fs_descriptors;
> }
>
> + cdev = get_gadget_data(g);
> + if (incomplete_desc != 0)
> + WARNING(cdev,
> + "%s function doesn't hold all the descriptors for supported speep\n",
"%s doesn't hold the descriptors for current speed"
> + f->name);
> +
> /* find correct alternate setting descriptor */
> for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
> int_desc = (struct usb_interface_descriptor *)*d_spd;
> @@ -244,12 +261,8 @@ int config_ep_by_speed_and_alt(struct usb_gadget *g,
> _ep->maxburst = comp_desc->bMaxBurst + 1;
> break;
> default:
> - if (comp_desc->bMaxBurst != 0) {
> - struct usb_composite_dev *cdev;
> -
> - cdev = get_gadget_data(g);
> + if (comp_desc->bMaxBurst != 0)
> ERROR(cdev, "ep0 bMaxBurst must be 0\n");
> - }
> _ep->maxburst = 1;
> break;
> }
> --
> 2.25.1
>
>
> Thanks for your suggestion, this is my revised patch.
> Of course, I will continue to fix android f_audio_source.c to solve the problem fundamentally.
>
> Thanks
Other things are ok for me. You could send v2 version after addressing my comments.
--
Thanks,
Peter Chen
