On Thu, Feb 22, 2018 at 12:32:04PM +0100, Kevin Wolf wrote: > Am 22.02.2018 um 12:01 hat Peter Lieven geschrieben: > > Am 22.02.2018 um 11:57 schrieb Kevin Wolf: > > > Am 20.02.2018 um 22:54 hat Paolo Bonzini geschrieben: > > >> On 20/02/2018 18:04, Peter Lieven wrote: > > >>> Hi, > > >>> > > >>> I remember we discussed a long time ago to limit the stack usage of all > > >>> functions that are executed in a coroutine > > >>> context to a very low value to be able to safely limit the coroutine > > >>> stack size as well. > > >> IIRC the only issue was that hw/ide/atapi.c has mutual recursion between > > >> ide_atapi_cmd_reply_end -> ide_transfer_start -> ahci_start_transfer -> > > >> ide_atapi_cmd_reply_end. > > >> > > >> But perhaps it's not an issue, somebody needs to audit the code. > > > I think John intended to get rid of the recursion sometime, but I doubt > > > he has had the time so far. > > > > Apart from this is is possible to define special cflags in the > > Makefile.objs just for a subdirectory? I have patches ready to make > > the block layer files and other coroutine users compile with > > -Wstack-size=2048. But I do not want to specify each file separately. > > Our Makefiles have lines like this: > > iscsi.o-cflags := $(LIBISCSI_CFLAGS) > > I don't think there is a direct mechanism to apply cflags to a whole > directory or just to block-obj-y/block-obj-m, but just looping over them > could work. I'm not a Makefile expert at all, but after some toying with > a simple example, something like this might work: > > $(foreach x,$(block-obj-y),$(eval $x-cflags += -Wstack-size=2048))
You'll need it for anything block layer depends on too - so that's much of util/, crypto/ and io/ directories at least. So perhaps it would be shorter if we do the opposite - set -Wstack-size=2048 globally for everything in QEMU, and then override -Wstack-size=$BIGGER for the (hopefully) few sources that have a larger stack need ? Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
