/* * ChaCha20 256-bit cipher algorithm, RFC7539 * * Copyright (C) 2015 Martin Willi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include #include #include #include #include #include static inline u32 rotl32(u32 v, u8 n) { return (v << n) | (v >> (sizeof(v) * 8 - n)); } extern void chacha20_block(u32 *state, void *stream) { u32 x[16], *out = stream; int i; for (i = 0; i < ARRAY_SIZE(x); i++) x[i] = state[i]; for (i = 0; i < 20; i += 2) { x[0] += x[4]; x[12] = rotl32(x[12] ^ x[0], 16); x[1] += x[5]; x[13] = rotl32(x[13] ^ x[1], 16); x[2] += x[6]; x[14] = rotl32(x[14] ^ x[2], 16); x[3] += x[7]; x[15] = rotl32(x[15] ^ x[3], 16); x[8] += x[12]; x[4] = rotl32(x[4] ^ x[8], 12); x[9] += x[13]; x[5] = rotl32(x[5] ^ x[9], 12); x[10] += x[14]; x[6] = rotl32(x[6] ^ x[10], 12); x[11] += x[15]; x[7] = rotl32(x[7] ^ x[11], 12); x[0] += x[4]; x[12] = rotl32(x[12] ^ x[0], 8); x[1] += x[5]; x[13] = rotl32(x[13] ^ x[1], 8); x[2] += x[6]; x[14] = rotl32(x[14] ^ x[2], 8); x[3] += x[7]; x[15] = rotl32(x[15] ^ x[3], 8); x[8] += x[12]; x[4] = rotl32(x[4] ^ x[8], 7); x[9] += x[13]; x[5] = rotl32(x[5] ^ x[9], 7); x[10] += x[14]; x[6] = rotl32(x[6] ^ x[10], 7); x[11] += x[15]; x[7] = rotl32(x[7] ^ x[11], 7); x[0] += x[5]; x[15] = rotl32(x[15] ^ x[0], 16); x[1] += x[6]; x[12] = rotl32(x[12] ^ x[1], 16); x[2] += x[7]; x[13] = rotl32(x[13] ^ x[2], 16); x[3] += x[4]; x[14] = rotl32(x[14] ^ x[3], 16); x[10] += x[15]; x[5] = rotl32(x[5] ^ x[10], 12); x[11] += x[12]; x[6] = rotl32(x[6] ^ x[11], 12); x[8] += x[13]; x[7] = rotl32(x[7] ^ x[8], 12); x[9] += x[14]; x[4] = rotl32(x[4] ^ x[9], 12); x[0] += x[5]; x[15] = rotl32(x[15] ^ x[0], 8); x[1] += x[6]; x[12] = rotl32(x[12] ^ x[1], 8); x[2] += x[7]; x[13] = rotl32(x[13] ^ x[2], 8); x[3] += x[4]; x[14] = rotl32(x[14] ^ x[3], 8); x[10] += x[15]; x[5] = rotl32(x[5] ^ x[10], 7); x[11] += x[12]; x[6] = rotl32(x[6] ^ x[11], 7); x[8] += x[13]; x[7] = rotl32(x[7] ^ x[8], 7); x[9] += x[14]; x[4] = rotl32(x[4] ^ x[9], 7); } for (i = 0; i < ARRAY_SIZE(x); i++) out[i] = cpu_to_le32(x[i] + state[i]); state[12]++; } EXPORT_SYMBOL(chacha20_block); >
path: root/include/acpi/cppc_acpi.h
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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 /include/acpi/cppc_acpi.h
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 'include/acpi/cppc_acpi.h')