On 12/15/20 4:41 PM, Peter Maydell wrote: > 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 >
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
