/* Software floating-point emulation. Copyright (C) 1997,1998,1999 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Richard Henderson (rth@cygnus.com), Jakub Jelinek (jj@ultra.linux.cz), David S. Miller (davem@redhat.com) and Peter Maydell (pmaydell@chiark.greenend.org.uk). The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifndef __MATH_EMU_SOFT_FP_H__ #define __MATH_EMU_SOFT_FP_H__ #include /* Allow sfp-machine to have its own byte order definitions. */ #ifndef __BYTE_ORDER #include #endif #define _FP_WORKBITS 3 #define _FP_WORK_LSB ((_FP_W_TYPE)1 << 3) #define _FP_WORK_ROUND ((_FP_W_TYPE)1 << 2) #define _FP_WORK_GUARD ((_FP_W_TYPE)1 << 1) #define _FP_WORK_STICKY ((_FP_W_TYPE)1 << 0) #ifndef FP_RND_NEAREST # define FP_RND_NEAREST 0 # define FP_RND_ZERO 1 # define FP_RND_PINF 2 # define FP_RND_MINF 3 #ifndef FP_ROUNDMODE # define FP_ROUNDMODE FP_RND_NEAREST #endif #endif /* By default don't care about exceptions. */ #ifndef FP_EX_INVALID #define FP_EX_INVALID 0 #endif #ifndef FP_EX_INVALID_SNAN #define FP_EX_INVALID_SNAN 0 #endif /* inf - inf */ #ifndef FP_EX_INVALID_ISI #define FP_EX_INVALID_ISI 0 #endif /* inf / inf */ #ifndef FP_EX_INVALID_IDI #define FP_EX_INVALID_IDI 0 #endif /* 0 / 0 */ #ifndef FP_EX_INVALID_ZDZ #define FP_EX_INVALID_ZDZ 0 #endif /* inf * 0 */ #ifndef FP_EX_INVALID_IMZ #define FP_EX_INVALID_IMZ 0 #endif #ifndef FP_EX_OVERFLOW #define FP_EX_OVERFLOW 0 #endif #ifndef FP_EX_UNDERFLOW #define FP_EX_UNDERFLOW #endif #ifndef FP_EX_DIVZERO #define FP_EX_DIVZERO 0 #endif #ifndef FP_EX_INEXACT #define FP_EX_INEXACT 0 #endif #ifndef FP_EX_DENORM #define FP_EX_DENORM 0 #endif #ifdef _FP_DECL_EX #define FP_DECL_EX \ int _fex = 0; \ _FP_DECL_EX #else #define FP_DECL_EX int _fex = 0 #endif #ifndef FP_INIT_ROUNDMODE #define FP_INIT_ROUNDMODE do {} while (0) #endif #ifndef FP_HANDLE_EXCEPTIONS #define FP_HANDLE_EXCEPTIONS do {} while (0) #endif /* By default we never flush denormal input operands to signed zero. */ #ifndef FP_DENORM_ZERO #define FP_DENORM_ZERO 0 #endif #ifndef FP_INHIBIT_RESULTS /* By default we write the results always. * sfp-machine may override this and e.g. * check if some exceptions are unmasked * and inhibit it in such a case. */ #define FP_INHIBIT_RESULTS 0 #endif #ifndef FP_TRAPPING_EXCEPTIONS #define FP_TRAPPING_EXCEPTIONS 0 #endif #define FP_SET_EXCEPTION(ex) \ _fex |= (ex) #define FP_UNSET_EXCEPTION(ex) \ _fex &= ~(ex) #define FP_CUR_EXCEPTIONS \ (_fex) #define FP_CLEAR_EXCEPTIONS \ _fex = 0 #define _FP_ROUND_NEAREST(wc, X) \ do { \ if ((_FP_FRAC_LOW_##wc(X) & 15) != _FP_WORK_ROUND) \ _FP_FRAC_ADDI_##wc(X, _FP_WORK_ROUND); \ } while (0) #define _FP_ROUND_ZERO(wc, X) 0 #define _FP_ROUND_PINF(wc, X) \ do { \ if (!X##_s && (_FP_FRAC_LOW_##wc(X) & 7)) \ _FP_FRAC_ADDI_##wc(X, _FP_WORK_LSB); \ } while (0) #define _FP_ROUND_MINF(wc, X) \ do { \ if (X##_s && (_FP_FRAC_LOW_##wc(X) & 7)) \ _FP_FRAC_ADDI_##wc(X, _FP_WORK_LSB); \ } while (0) #define _FP_ROUND(wc, X) \ do { \ if (_FP_FRAC_LOW_##wc(X) & 7) \ FP_SET_EXCEPTION(FP_EX_INEXACT); \ switch (FP_ROUNDMODE) \ { \ case FP_RND_NEAREST: \ _FP_ROUND_NEAREST(wc,X); \ break; \ case FP_RND_ZERO: \ _FP_ROUND_ZERO(wc,X); \ break; \ case FP_RND_PINF: \ _FP_ROUND_PINF(wc,X); \ break; \ case FP_RND_MINF: \ _FP_ROUND_MINF(wc,X); \ break; \ } \ } while (0) #define FP_CLS_NORMAL 0 #define FP_CLS_ZERO 1 #define FP_CLS_INF 2 #define FP_CLS_NAN 3 #define _FP_CLS_COMBINE(x,y) (((x) << 2) | (y)) #include #include #include #include #include /* Sigh. Silly things longlong.h needs. */ #define UWtype _FP_W_TYPE #define W_TYPE_SIZE _FP_W_TYPE_SIZE typedef int SItype __attribute__((mode(SI))); typedef int DItype __attribute__((mode(DI))); typedef unsigned int USItype __attribute__((mode(SI))); typedef unsigned int UDItype __attribute__((mode(DI))); #if _FP_W_TYPE_SIZE == 32 typedef unsigned int UHWtype __attribute__((mode(HI))); #elif _FP_W_TYPE_SIZE == 64 typedef USItype UHWtype; #endif #ifndef umul_ppmm #include #endif #endif /* __MATH_EMU_SOFT_FP_H__ */ <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/trace/events/cma.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/trace/events/cma.h')