Revision 10f1d5d111e8aed46a0f1179faf9a3cf422f689e authored by Joe Thornber on 27 June 2014, 19:29:04 UTC, committed by Mike Snitzer on 10 July 2014, 20:44:14 UTC
There's a race condition between the atomic_dec_and_test(&io->count)
in dec_count() and the waking of the sync_io() thread.  If the thread
is spuriously woken immediately after the decrement it may exit,
making the on stack io struct invalid, yet the dec_count could still
be using it.

Fix this race by using a completion in sync_io() and dec_count().

Reported-by: Minfei Huang <huangminfei@ucloud.cn>
Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
1 parent bf14299
Raw File
Makefile
###
# scripts contains sources for various helper programs used throughout
# the kernel for the build process.
# ---------------------------------------------------------------------------
# kallsyms:      Find all symbols in vmlinux
# pnmttologo:    Convert pnm files to logo files
# conmakehash:   Create chartable
# conmakehash:	 Create arrays for initializing the kernel console tables
# docproc:       Used in Documentation/DocBook

HOST_EXTRACFLAGS += -I$(srctree)/tools/include

hostprogs-$(CONFIG_KALLSYMS)     += kallsyms
hostprogs-$(CONFIG_LOGO)         += pnmtologo
hostprogs-$(CONFIG_VT)           += conmakehash
hostprogs-$(CONFIG_IKCONFIG)     += bin2c
hostprogs-$(BUILD_C_RECORDMCOUNT) += recordmcount
hostprogs-$(CONFIG_BUILDTIME_EXTABLE_SORT) += sortextable
hostprogs-$(CONFIG_ASN1)	 += asn1_compiler

HOSTCFLAGS_sortextable.o = -I$(srctree)/tools/include
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include

always		:= $(hostprogs-y) $(hostprogs-m)

# The following hostprogs-y programs are only build on demand
hostprogs-y += unifdef docproc

# These targets are used internally to avoid "is up to date" messages
PHONY += build_unifdef build_docproc
build_unifdef: $(obj)/unifdef
	@:
build_docproc: $(obj)/docproc
	@:

subdir-$(CONFIG_MODVERSIONS) += genksyms
subdir-y                     += mod
subdir-$(CONFIG_SECURITY_SELINUX) += selinux
subdir-$(CONFIG_DTC)         += dtc

# Let clean descend into subdirs
subdir-	+= basic kconfig package
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