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path: root/drivers/net/ppp/ppp_async.c
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2013-03-18tty: Fix recursive deadlock in tty_perform_flush()Peter Hurley
tty_perform_flush() can deadlock when called while holding a line discipline reference. By definition, all ldisc drivers hold a ldisc reference, so calls originating from ldisc drivers must not block for a ldisc reference. The deadlock can occur when: CPU 0 | CPU 1 | tty_ldisc_ref(tty) | .... | <line discipline halted> tty_ldisc_ref_wait(tty) | | CPU 0 cannot progess because it cannot obtain an ldisc reference with the line discipline has been halted (thus no new references are granted). CPU 1 cannot progress because an outstanding ldisc reference has not been released. An in-tree call-tree audit of tty_perform_flush() [1] shows 5 ldisc drivers calling tty_perform_flush() indirectly via n_tty_ioctl_helper() and 2 ldisc drivers calling directly. A single tty driver safely uses the function. [1] Recursive usage: /* These functions are line discipline ioctls and thus * recursive wrt line discipline references */ tty_perform_flush() - ./drivers/tty/tty_ioctl.c n_tty_ioctl_helper() hci_uart_tty_ioctl(default) - drivers/bluetooth/hci_ldisc.c (N_HCI) n_hdlc_tty_ioctl(default) - drivers/tty/n_hdlc.c (N_HDLC) gsmld_ioctl(default) - drivers/tty/n_gsm.c (N_GSM0710) n_tty_ioctl(default) - drivers/tty/n_tty.c (N_TTY) gigaset_tty_ioctl(default) - drivers/isdn/gigaset/ser-gigaset.c (N_GIGASET_M101) ppp_synctty_ioctl(TCFLSH) - drivers/net/ppp/pps_synctty.c ppp_asynctty_ioctl(TCFLSH) - drivers/net/ppp/ppp_async.c Non-recursive use: tty_perform_flush() - drivers/tty/tty_ioctl.c ipw_ioctl(TCFLSH) - drivers/tty/ipwireless/tty.c /* This function is a tty i/o ioctl method, which * is invoked by tty_ioctl() */ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-19ppp: avoid false drop_monitor false positivesEric Dumazet
Call consume_skb() in place of kfree_skb() were appropriate. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-05ppp: Replace uses of <linux/if_ppp.h> with <linux/ppp-ioctl.h>Paul Mackerras
Since all that include/linux/if_ppp.h does is #include <linux/ppp-ioctl.h>, this replaces the occurrences of #include <linux/if_ppp.h> with #include <linux/ppp-ioctl.h>. It also corrects an error in Documentation/networking/l2tp.txt, where it referenced include/linux/if_ppp.h as the source of some definitions that are actually now defined in include/linux/if_pppol2tp.h. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-27ppp: Move the PPP driversJeff Kirsher
Move the PPP drivers into drivers/net/ppp/ and make the necessary Kconfig and Makefile changes. CC: Paul Mackerras <paulus@samba.org> CC: Frank Cusack <fcusack@fcusack.com> CC: Michal Ostrowski <mostrows@speakeasy.net> CC: Michal Ostrowski <mostrows@earthlink.net> CC: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>