#ifndef _DWARF_AUX_H #define _DWARF_AUX_H /* * dwarf-aux.h : libdw auxiliary interfaces * * 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. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * */ #include #include #include #include /* Find the realpath of the target file */ const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname); /* Get DW_AT_comp_dir (should be NULL with older gcc) */ const char *cu_get_comp_dir(Dwarf_Die *cu_die); /* Get a line number and file name for given address */ int cu_find_lineinfo(Dwarf_Die *cudie, unsigned long addr, const char **fname, int *lineno); /* Walk on funcitons at given address */ int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr, int (*callback)(Dwarf_Die *, void *), void *data); /* Get DW_AT_linkage_name (should be NULL for C binary) */ const char *die_get_linkage_name(Dwarf_Die *dw_die); /* Ensure that this DIE is a subprogram and definition (not declaration) */ bool die_is_func_def(Dwarf_Die *dw_die); /* Ensure that this DIE is an instance of a subprogram */ bool die_is_func_instance(Dwarf_Die *dw_die); /* Compare diename and tname */ bool die_compare_name(Dwarf_Die *dw_die, const char *tname); /* Matching diename with glob pattern */ bool die_match_name(Dwarf_Die *dw_die, const char *glob); /* Get callsite line number of inline-function instance */ int die_get_call_lineno(Dwarf_Die *in_die); /* Get callsite file name of inlined function instance */ const char *die_get_call_file(Dwarf_Die *in_die); /* Get type die */ Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem); /* Get a type die, but skip qualifiers and typedef */ Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem); /* Check whether the DIE is signed or not */ bool die_is_signed_type(Dwarf_Die *tp_die); /* Get data_member_location offset */ int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs); /* Return values for die_find_child() callbacks */ enum { DIE_FIND_CB_END = 0, /* End of Search */ DIE_FIND_CB_CHILD = 1, /* Search only children */ DIE_FIND_CB_SIBLING = 2, /* Search only siblings */ DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */ }; /* Search child DIEs */ Dwarf_Die *die_find_child(Dwarf_Die *rt_die, int (*callback)(Dwarf_Die *, void *), void *data, Dwarf_Die *die_mem); /* Search a non-inlined function including given address */ Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, Dwarf_Die *die_mem); /* Search a non-inlined function with tail call at given address */ Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, Dwarf_Die *die_mem); /* Search the top inlined function including given address */ Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, Dwarf_Die *die_mem); /* Search the deepest inlined function including given address */ Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, Dwarf_Die *die_mem); /* Walk on the instances of given DIE */ int die_walk_instances(Dwarf_Die *in_die, int (*callback)(Dwarf_Die *, void *), void *data); /* Walker on lines (Note: line number will not be sorted) */ typedef int (* line_walk_callback_t) (const char *fname, int lineno, Dwarf_Addr addr, void *data); /* * Walk on lines inside given DIE. If the DIE is a subprogram, walk only on * the lines inside the subprogram, otherwise the DIE must be a CU DIE. */ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data); /* Find a variable called 'name' at given address */ Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name, Dwarf_Addr addr, Dwarf_Die *die_mem); /* Find a member called 'name' */ Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, Dwarf_Die *die_mem); /* Get the name of given variable DIE */ int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf); /* Get the name and type of given variable DIE, stored as "type\tname" */ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf); int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf); /* Check if target program is compiled with optimization */ bool die_is_optimized_target(Dwarf_Die *cu_die); /* Use next address after prologue as probe location */ void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die, Dwarf_Addr *entrypc); #endif 'commit info' class='commit-info'> 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 /sound/soc/codecs/max98926.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 'sound/soc/codecs/max98926.h')