#! /usr/bin/perl -w # convert an Intel HEX file into a set of C records usable by the firmware # loading code in usb-serial.c (or others) # accepts the .hex file(s) on stdin, a basename (to name the initialized # array) as an argument, and prints the .h file to stdout. Typical usage: # perl ezusb_convert.pl foo fw_foo.h my $basename = $ARGV[0]; die "no base name specified" unless $basename; while () { # ':' '\r' # len, type, crc are 2-char hex, addr is 4-char hex. type is 00 for # normal records, 01 for EOF my($lenstring, $addrstring, $typestring, $reststring, $doscrap) = /^:(\w\w)(\w\w\w\w)(\w\w)(\w+)(\r?)$/; die "malformed line: $_" unless $reststring; last if $typestring eq '01'; my($len) = hex($lenstring); my($addr) = hex($addrstring); my(@bytes) = unpack("C*", pack("H".(2*$len), $reststring)); #pop(@bytes); # last byte is a CRC push(@records, [$addr, \@bytes]); } @sorted_records = sort { $a->[0] <=> $b->[0] } @records; print <<"EOF"; /* * ${basename}_fw.h * * Generated from ${basename}.s by ezusb_convert.pl * This file is presumed to be under the same copyright as the source file * from which it was derived. */ EOF print "static const struct ezusb_hex_record ${basename}_firmware[] = {\n"; foreach $r (@sorted_records) { printf("{ 0x%04x,\t%d,\t{", $r->[0], scalar(@{$r->[1]})); print join(", ", map {sprintf('0x%02x', $_);} @{$r->[1]}); print "} },\n"; } print "{ 0xffff,\t0,\t{0x00} }\n"; print "};\n"; summaryrefslogtreecommitdiff
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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 /kernel/compat.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 'kernel/compat.c')