# ==========================================================================
# Generating modules.builtin
# ==========================================================================
src := $(obj)
PHONY := __modbuiltin
__modbuiltin:
-include include/config/auto.conf
# tristate.conf sets tristate variables to uppercase 'Y' or 'M'
# That way, we get the list of built-in modules in obj-Y
-include include/config/tristate.conf
include scripts/Kbuild.include
ifneq ($(KBUILD_SRC),)
# Create output directory if not already present
_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
endif
# The filename Kbuild has precedence over Makefile
kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
include $(kbuild-file)
include scripts/Makefile.lib
__subdir-Y := $(patsubst %/,%,$(filter %/, $(obj-Y)))
subdir-Y += $(__subdir-Y)
subdir-ym := $(sort $(subdir-y) $(subdir-Y) $(subdir-m))
subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
obj-Y := $(addprefix $(obj)/,$(obj-Y))
modbuiltin-subdirs := $(patsubst %,%/modules.builtin, $(subdir-ym))
modbuiltin-mods := $(filter %.ko, $(obj-Y:.o=.ko))
modbuiltin-target := $(obj)/modules.builtin
__modbuiltin: $(modbuiltin-target) $(subdir-ym)
@:
$(modbuiltin-target): $(subdir-ym) FORCE
$(Q)(for m in $(modbuiltin-mods); do echo kernel/$$m; done; \
cat /dev/null $(modbuiltin-subdirs)) > $@
PHONY += FORCE
FORCE:
# Descending
# ---------------------------------------------------------------------------
PHONY += $(subdir-ym)
$(subdir-ym):
$(Q)$(MAKE) $(modbuiltin)=$@
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.
.PHONY: $(PHONY)
f='/cgit.cgi/linux/net-next.git/tree/tools/testing/radix-tree?h=nds-private-remove&id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>treecommitdiff
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:
Double lock:
1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236;
2. call to function `pl330_release_channel' immediately after;
3. call to function `dma_pl330_rqcb' in line 1753;
4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505.
I have fixed it as suggested by Marek Szyprowski.
First, I have replaced `pch->lock' with `pl330->lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.
NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch->work_list' under lock `pl330->lock',
whereas in the rest of the code `pch->work_list' is protected by
`pch->lock'. I don't know if this may cause race conditions. Similarly
`pch->cyclic' is written by `pl330_alloc_chan_resources' under
`pl330->lock' but read by `pl330_tx_submit' under `pch->lock'.
Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.
Signed-off-by: Iago Abal <mail@iagoabal.eu>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>