[PATCH v2 0/4] qemu-timer: Make timer_free() imply timer_del()

[Peter Maydell]

Currently timer_free() is a simple wrapper for g_free().  This means
that the timer being freed must not be currently active, as otherwise
QEMU might crash later when the active list is processed and still
has a pointer to freed memory on it.  As a result almost all calls to
timer_free() are preceded by a timer_del() call, as can be seen in
the output of
  git grep -B1 '\<timer_free\>'

This is unfortunate API design as it makes it easy to accidentally
misuse (by forgetting the timer_del()), and the correct use is
annoyingly verbose.

Patch 1 makes timer_free() call timer_del() if the timer is active.
Patch 2 is a Coccinelle script to remove any timer_del() calls
that are immediately before the timer_free().
Patch 3 is the result of running the Coccinelle script on the
whole tree.
Patch 4 makes a by-hand cleanup of a bit of the Arm CPU code
not caught by Coccinelle because it included a pointless
timer_deinit() between timer_del() and timer_free().

I could split up patch 3, but for 58 deleted lines over 42 files
created entirely automatedly, it seemed to me to be simpler as one
patch.

Changes v1->v2:
 * patch 1: unconditionally call timer_del() rather than trying
   to be clever
 * patch 4: new patch

thanks
-- PMM

Peter Maydell (4):
  util/qemu-timer: Make timer_free() imply timer_del()
  scripts/coccinelle: New script to remove unnecessary timer_del() calls
  Remove superfluous timer_del() calls
  target/arm: Remove timer_del()/timer_deinit() before timer_free()

 scripts/coccinelle/timer-del-timer-free.cocci | 18 +++++++++++++
 include/qemu/timer.h                          | 25 +++++++++++--------
 block/iscsi.c                                 |  2 --
 block/nbd.c                                   |  1 -
 block/qcow2.c                                 |  1 -
 hw/block/nvme.c                               |  2 --
 hw/char/serial.c                              |  2 --
 hw/char/virtio-serial-bus.c                   |  2 --
 hw/ide/core.c                                 |  1 -
 hw/input/hid.c                                |  1 -
 hw/intc/apic.c                                |  1 -
 hw/intc/ioapic.c                              |  1 -
 hw/ipmi/ipmi_bmc_extern.c                     |  1 -
 hw/net/e1000.c                                |  3 ---
 hw/net/e1000e_core.c                          |  8 ------
 hw/net/pcnet-pci.c                            |  1 -
 hw/net/rtl8139.c                              |  1 -
 hw/net/spapr_llan.c                           |  1 -
 hw/net/virtio-net.c                           |  2 --
 hw/s390x/s390-pci-inst.c                      |  1 -
 hw/sd/sd.c                                    |  1 -
 hw/sd/sdhci.c                                 |  2 --
 hw/usb/dev-hub.c                              |  1 -
 hw/usb/hcd-ehci.c                             |  1 -
 hw/usb/hcd-ohci-pci.c                         |  1 -
 hw/usb/hcd-uhci.c                             |  1 -
 hw/usb/hcd-xhci.c                             |  1 -
 hw/usb/redirect.c                             |  1 -
 hw/vfio/display.c                             |  1 -
 hw/virtio/vhost-vsock-common.c                |  1 -
 hw/virtio/virtio-balloon.c                    |  1 -
 hw/virtio/virtio-rng.c                        |  1 -
 hw/watchdog/wdt_diag288.c                     |  1 -
 hw/watchdog/wdt_i6300esb.c                    |  1 -
 migration/colo.c                              |  1 -
 monitor/hmp-cmds.c                            |  1 -
 net/announce.c                                |  1 -
 net/colo-compare.c                            |  1 -
 net/slirp.c                                   |  1 -
 replay/replay-debugging.c                     |  1 -
 target/arm/cpu.c                              |  2 --
 target/s390x/cpu.c                            |  2 --
 ui/console.c                                  |  1 -
 ui/spice-core.c                               |  1 -
 util/throttle.c                               |  1 -
 45 files changed, 32 insertions(+), 71 deletions(-)
 create mode 100644 scripts/coccinelle/timer-del-timer-free.cocci

-- 
2.20.1