TARGETS = bpf TARGETS += breakpoints TARGETS += capabilities TARGETS += cpu-hotplug TARGETS += efivarfs TARGETS += exec TARGETS += firmware TARGETS += ftrace TARGETS += futex TARGETS += gpio TARGETS += ipc TARGETS += kcmp TARGETS += lib TARGETS += membarrier TARGETS += memfd TARGETS += memory-hotplug TARGETS += mount TARGETS += mqueue TARGETS += net TARGETS += nsfs TARGETS += powerpc TARGETS += pstore TARGETS += ptrace TARGETS += seccomp TARGETS += sigaltstack TARGETS += size TARGETS += static_keys TARGETS += sync TARGETS += sysctl ifneq (1, $(quicktest)) TARGETS += timers endif TARGETS += user TARGETS += vm TARGETS += x86 TARGETS += zram #Please keep the TARGETS list alphabetically sorted # Run "make quicktest=1 run_tests" or # "make quicktest=1 kselftest from top level Makefile TARGETS_HOTPLUG = cpu-hotplug TARGETS_HOTPLUG += memory-hotplug # Clear LDFLAGS and MAKEFLAGS if called from main # Makefile to avoid test build failures when test # Makefile doesn't have explicit build rules. ifeq (1,$(MAKELEVEL)) override LDFLAGS = override MAKEFLAGS = endif all: for TARGET in $(TARGETS); do \ make -C $$TARGET; \ done; run_tests: all for TARGET in $(TARGETS); do \ make -C $$TARGET run_tests; \ done; hotplug: for TARGET in $(TARGETS_HOTPLUG); do \ make -C $$TARGET; \ done; run_hotplug: hotplug for TARGET in $(TARGETS_HOTPLUG); do \ make -C $$TARGET run_full_test; \ done; clean_hotplug: for TARGET in $(TARGETS_HOTPLUG); do \ make -C $$TARGET clean; \ done; run_pstore_crash: make -C pstore run_crash INSTALL_PATH ?= install INSTALL_PATH := $(abspath $(INSTALL_PATH)) ALL_SCRIPT := $(INSTALL_PATH)/run_kselftest.sh install: ifdef INSTALL_PATH @# Ask all targets to install their files mkdir -p $(INSTALL_PATH) for TARGET in $(TARGETS); do \ make -C $$TARGET INSTALL_PATH=$(INSTALL_PATH)/$$TARGET install; \ done; @# Ask all targets to emit their test scripts echo "#!/bin/sh" > $(ALL_SCRIPT) echo "cd \$$(dirname \$$0)" >> $(ALL_SCRIPT) echo "ROOT=\$$PWD" >> $(ALL_SCRIPT) for TARGET in $(TARGETS); do \ echo "echo ; echo Running tests in $$TARGET" >> $(ALL_SCRIPT); \ echo "echo ========================================" >> $(ALL_SCRIPT); \ echo "cd $$TARGET" >> $(ALL_SCRIPT); \ make -s --no-print-directory -C $$TARGET emit_tests >> $(ALL_SCRIPT); \ echo "cd \$$ROOT" >> $(ALL_SCRIPT); \ done; chmod u+x $(ALL_SCRIPT) else $(error Error: set INSTALL_PATH to use install) endif clean: for TARGET in $(TARGETS); do \ make -C $$TARGET clean; \ done; .PHONY: install t class='txt' type='search' size='10' name='q' value=''/>
path: root/drivers/usb/dwc3/gadget.c
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /drivers/usb/dwc3/gadget.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')