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| author | Austin Morton <austinpmorton@gmail.com> | 2017-12-27 05:53:41 -0500 |
|---|---|---|
| committer | Austin Morton <austinpmorton@gmail.com> | 2018-10-01 17:57:11 -0400 |
| commit | 40769f9bd350be59b9a9ef944c77d63cfc883f2e (patch) | |
| tree | ce7d701e2b9005eb7d878173050e5d49aa564ae6 /os | |
| parent | ca79ff2e87ed8b483cf7c889ec7225d9703bc2da (diff) | |
| download | ChibiOS-Contrib-40769f9bd350be59b9a9ef944c77d63cfc883f2e.tar.gz ChibiOS-Contrib-40769f9bd350be59b9a9ef944c77d63cfc883f2e.tar.bz2 ChibiOS-Contrib-40769f9bd350be59b9a9ef944c77d63cfc883f2e.zip | |
avoid using list_for_each_entry_safe when closing endpoints to prevent potential infinite loop
list_for_each_entry_safe is only safe when the current entry is being removed.
If other entries in the list could potentially be removed it can result in an infinite loop.
Because usbh_lld_ep_close blocks on each urb during iteration, it may give up its lock on
the system and allow an interrupt to remove a different urb from the list,
resulting in an infinite loop when the thread resumes.
Diffstat (limited to 'os')
| -rw-r--r-- | os/hal/ports/STM32/LLD/USBHv1/hal_usbh_lld.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/os/hal/ports/STM32/LLD/USBHv1/hal_usbh_lld.c b/os/hal/ports/STM32/LLD/USBHv1/hal_usbh_lld.c index a0583a6..3298c20 100644 --- a/os/hal/ports/STM32/LLD/USBHv1/hal_usbh_lld.c +++ b/os/hal/ports/STM32/LLD/USBHv1/hal_usbh_lld.c @@ -594,9 +594,10 @@ void usbh_lld_ep_open(usbh_ep_t *ep) { } void usbh_lld_ep_close(usbh_ep_t *ep) { - usbh_urb_t *urb, *tmp; + usbh_urb_t *urb; uinfof("\t%s: Closing EP...", ep->name); - list_for_each_entry_safe(urb, usbh_urb_t, tmp, &ep->urb_list, node) { + while (!list_empty(&ep->urb_list)) { + urb = list_first_entry(&ep->urb_list, usbh_urb_t, node); uinfof("\t%s: Abort URB, USBH_URBSTATUS_DISCONNECTED", ep->name); _usbh_urb_abort_and_waitS(urb, USBH_URBSTATUS_DISCONNECTED); } |