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Documented in 1 files:

Defined in 1 files as a prototype:

Defined in 1 files as a function:

Referenced in 14 files:

Smatch caller information:

fs/splice.c do_splice_read() -> copy_splice_read()

Type Parameter Key Value
PARAM_VALUE 0 in 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_mapping 4096-ptr_max
PARAM_VALUE 0 in->f_mapping->host 4096-ptr_max
PARAM_VALUE 0 in->f_op 4096-ptr_max
PARAM_VALUE 0 in->f_op->splice_read 1-u64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->encode_fh 0,2,1398972869330624512,1616549510479982592,2037984473558433792,2776440803454029824,3228746867770966016,3502492669594062848,3526768263295340544,3559173554394271744,5000850239487131648,5583386343686406144,5817357685191483392-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->fh_to_dentry 0,8684,447817974243774464,687732489194512384,742201802719268864,868497899885588480,1471448175530500096,2021658383390310400,2445877819203563520,2512819722689847296,2649270699546726400,2761259683714371584,2893332316235677696-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->fh_to_parent 0,4672,148606482432692224,436469935444291584,457356038048772096,467281172929331200,529780027764285440,1092893949038768128,1556959531105513472,1608953577475584000,1649536479961075712,2404761408063094784,2970908329832960000-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->get_parent 0,8931,264940071972966400,291591359766798336,565128213429456896,893189740598853632,1241177127089143808,1474696885321834496,1812477326828269568,1893665921928286208,2210088671756947456,2437012291923775488,2483979068402987008-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->empty_dir 0,86,661756434209751040,4392966320616476672,5234023279986843648,8614756098313990144
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->get_context 0,706,17350455714160640,4513809449498124288,5149251875611672576,7067778626864828416
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->inode_info_offs 1632,1640,1720,1808,1816,2632,2640,2648,2704,2712
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->set_context 0,67,317457138841939968,3250154607523569664,5979066299606671360,6756104566897242112
PARAM_VALUE 1 ppos 4096-ptr_max
PARAM_VALUE 2 pipe 4096-ptr_max
PARAM_VALUE 3 len 0-2147479552
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
CAPPED_DATA 3 len 1
CAPPED_DATA 3 len 1
DATA_SOURCE 0 in $0
DATA_SOURCE 1 ppos $1
DATA_SOURCE 2 pipe $2
DATA_SOURCE 3 len $3 [m]
DATA_SOURCE 4 flags $4
FUZZY_MAX 3 len 2147479552
BIT_INFO 0 in->f_flags 0x0,0xffffffff
BIT_INFO 0 in->f_mode 0x1,0xffffffff
BIT_INFO 3 len 0x0,0xffffffff
NOSPEC 1 *ppos
NOSPEC 3 len
RX_PATH
TASK_NOT_RUNNING
USER_DATA 1 *ppos 0-15442450941
USER_DATA 3 len 1-2147479552[c]
USER_DATA 4 flags 0-16[c]
NO_OVERFLOW_SIMPLE 0 in->f_path.d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.dentry->d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.moved->d_inode->i_size
NO_OVERFLOW_SIMPLE 2 pipe->max_usage
NO_OVERFLOW_SIMPLE 2 pipe->nr_accounted
NO_OVERFLOW_SIMPLE 2 pipe->ring_size
NO_OVERFLOW_SIMPLE 3 len
UNITS 3 len unit_byte
USER_PTR 1 ppos

net/socket.c sock_splice_read() -> copy_splice_read()

Type Parameter Key Value
PARAM_VALUE 0 in 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->host->i_sb->s_export_op->fh_to_dentry 0,8684,447817974243774464,687732489194512384,742201802719268864,868497899885588480,1471448175530500096,2021658383390310400,2445877819203563520,2512819722689847296,2649270699546726400,2761259683714371584,2893332316235677696-s64max
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_mapping 4096-ptr_max
PARAM_VALUE 0 in->f_mapping->host 4096-ptr_max
PARAM_VALUE 0 in->f_op 4096-ptr_max
PARAM_VALUE 0 in->f_op->splice_read 1-u64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->inode_info_offs 1632,1640,1720,1808,1816,2632,2640,2648,2704,2712
PARAM_VALUE 1 ppos 4096-ptr_max
PARAM_VALUE 2 pipe 4096-ptr_max
PARAM_VALUE 3 len 0-2147479552
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
CAPPED_DATA 3 len 1
CAPPED_DATA 3 len 1
DATA_SOURCE 0 in $0
DATA_SOURCE 1 ppos $1
DATA_SOURCE 2 pipe $2
DATA_SOURCE 3 len $3
DATA_SOURCE 4 flags $4
FUZZY_MAX 3 len 2147479552
BIT_INFO 0 in->f_flags 0x0,0xffffbfff
BIT_INFO 0 in->f_mode 0x1,0xffffffff
BIT_INFO 3 len 0x0,0xffffffff
NOSPEC 1 *ppos
NOSPEC 3 len
NOSPEC 3 len
RX_PATH
TASK_NOT_RUNNING
USER_DATA 1 *ppos 0-13442450941
USER_DATA 3 len 1-2147479552[c]
USER_DATA 4 flags 0-16[c]
NO_OVERFLOW_SIMPLE 0 in->f_path.d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.dentry->d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.moved->d_inode->i_size
NO_OVERFLOW_SIMPLE 2 pipe->max_usage
NO_OVERFLOW_SIMPLE 2 pipe->nr_accounted
NO_OVERFLOW_SIMPLE 2 pipe->ring_size
NO_OVERFLOW_SIMPLE 3 len
USER_PTR 1 ppos

fs/9p/vfs_file.c v9fs_file_splice_read() -> copy_splice_read()

Type Parameter Key Value
PARAM_VALUE 0 in 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->host->i_sb->s_export_op->fh_to_dentry 0,8684,447817974243774464,687732489194512384,742201802719268864,868497899885588480,1471448175530500096,2021658383390310400,2445877819203563520,2512819722689847296,2649270699546726400,2761259683714371584,2893332316235677696-s64max
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_mapping 4096-ptr_max
PARAM_VALUE 0 in->f_mapping->host 4096-ptr_max
PARAM_VALUE 0 in->f_op 4096-ptr_max
PARAM_VALUE 0 in->f_op->splice_read 1-u64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->inode_info_offs 1632,1640,1720,1808,1816,2632,2640,2648,2704,2712
PARAM_VALUE 0 in->private_data 4096-ptr_max
PARAM_VALUE 1 ppos 4096-ptr_max
PARAM_VALUE 2 pipe 4096-ptr_max
PARAM_VALUE 3 len 0-2147479552
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
CAPPED_DATA 3 len 1
CAPPED_DATA 3 len 1
DATA_SOURCE 0 in $0
DATA_SOURCE 1 ppos $1
DATA_SOURCE 2 pipe $2
DATA_SOURCE 3 len $3
DATA_SOURCE 4 flags $4
FUZZY_MAX 3 len 2147479552
BIT_INFO 0 in->f_flags 0x0,0xffffbfff
BIT_INFO 0 in->f_mode 0x1,0xffffffff
BIT_INFO 3 len 0x0,0xffffffff
NOSPEC 1 *ppos
NOSPEC 3 len
NOSPEC 3 len
RX_PATH
TASK_NOT_RUNNING
USER_DATA 1 *ppos 0-13442450941
USER_DATA 3 len 1-2147479552[c]
USER_DATA 4 flags 0-16[c]
NO_OVERFLOW_SIMPLE 0 in->f_path.d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.dentry->d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.moved->d_inode->i_size
NO_OVERFLOW_SIMPLE 2 pipe->max_usage
NO_OVERFLOW_SIMPLE 2 pipe->nr_accounted
NO_OVERFLOW_SIMPLE 2 pipe->ring_size
NO_OVERFLOW_SIMPLE 3 len
USER_PTR 1 ppos

fs/ceph/file.c ceph_splice_read() -> copy_splice_read()

Type Parameter Key Value
PARAM_VALUE 0 in 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_sb 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info->mount_state s32min-3
PARAM_VALUE 0 in->f_mapping 4096-ptr_max
PARAM_VALUE 0 in->f_mapping->host 4096-ptr_max
PARAM_VALUE 0 in->f_op 4096-ptr_max
PARAM_VALUE 0 in->f_op->splice_read 1-u64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->inode_info_offs 1632,1640,1720,1808,1816,2632,2640,2648,2704,2712
PARAM_VALUE 1 ppos 4096-ptr_max
PARAM_VALUE 2 pipe 4096-ptr_max
PARAM_VALUE 3 len 0-2147479552
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
CAPPED_DATA 3 len 1
CAPPED_DATA 3 len 1
DATA_SOURCE 0 in $0
DATA_SOURCE 1 ppos $1
DATA_SOURCE 2 pipe $2
DATA_SOURCE 3 len $3
DATA_SOURCE 4 flags $4
FUZZY_MAX 3 len 2147479552
BIT_INFO 0 in->f_flags 0x0,0xffffbfff
BIT_INFO 0 in->f_mode 0x1,0xffffffffffffffff
BIT_INFO 3 len 0x0,0xffffffff
NOSPEC 1 *ppos
NOSPEC 3 len
NOSPEC 3 len
RX_PATH
TASK_NOT_RUNNING
USER_DATA 1 *ppos 0-13442450941
USER_DATA 3 len 1-2147479552[c]
USER_DATA 4 flags 0-16[c]
NO_OVERFLOW_SIMPLE 0 in->f_path.d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.dentry->d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.moved->d_inode->i_size
NO_OVERFLOW_SIMPLE 2 pipe->max_usage
NO_OVERFLOW_SIMPLE 2 pipe->nr_accounted
NO_OVERFLOW_SIMPLE 2 pipe->ring_size
NO_OVERFLOW_SIMPLE 3 len
USER_PTR 1 ppos

fs/ceph/file.c ceph_splice_read() -> copy_splice_read()

Type Parameter Key Value
PARAM_VALUE 0 in 4096-ptr_max
PARAM_VALUE 0 in->f_inode 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_flctx->flc_lock.rlock.dep_map->name 0-255
PARAM_VALUE 0 in->f_inode->i_mapping->host->i_sb->s_cop->empty_dir 0,86,4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->host->i_sb->s_cop->get_context 0,706,4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->host->i_sb->s_cop->set_context 0,67,4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.dep_map->name 0-255
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->handoff_set 1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->list.next 2212933610777083904,2624917664208203776
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->list.prev 2212933610777083904,2624917664208203776
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_sb 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info->mdsc->cap_wait_list.next->next 8374781174969200640
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info->mdsc->cap_wait_list.next->prev 8374781174969200640
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info->mdsc->caps_list_lock.rlock.dep_map->name 0-255
PARAM_VALUE 0 in->f_inode->i_sb->s_fs_info->mount_state s32min-3
PARAM_VALUE 0 in->f_inode->i_wb->dwork.wq->dfl_pwq 0-s64max
PARAM_VALUE 0 in->f_inode->i_wb->dwork.wq->saved_max_active s32min-s32max
PARAM_VALUE 0 in->f_inode->i_wb->dwork.wq->saved_min_active s32min-s32max
PARAM_VALUE 0 in->f_mapping 4096-ptr_max
PARAM_VALUE 0 in->f_mapping->host 4096-ptr_max
PARAM_VALUE 0 in->f_op 4096-ptr_max
PARAM_VALUE 0 in->f_op->splice_read 1-u64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->inode_info_offs 1632,1640,1720,1808,1816,2632,2640,2648,2704,2712
PARAM_VALUE 0 in->private_data 4096-ptr_max
PARAM_VALUE 0 in->private_data->fmode s16min-(-1),2-s16max
PARAM_VALUE 1 ppos 4096-ptr_max
PARAM_VALUE 2 pipe 4096-ptr_max
PARAM_VALUE 3 len 0-2147479552
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
CAPPED_DATA 3 len 1
CAPPED_DATA 3 len 1
DATA_SOURCE 0 in $0
DATA_SOURCE 1 ppos $1
DATA_SOURCE 2 pipe $2
DATA_SOURCE 3 len $3
DATA_SOURCE 4 flags $4
FUZZY_MAX 3 len 2147479552
BIT_INFO 0 in->f_flags 0x0,0xffffbfff
BIT_INFO 0 in->f_mode 0x1,0xffffffffffffffff
BIT_INFO 3 len 0x0,0xffffffff
NOSPEC 1 *ppos
NOSPEC 3 len
NOSPEC 3 len
RX_PATH
TASK_NOT_RUNNING
USER_DATA 1 *ppos 0-13442450941
USER_DATA 3 len 1-2147479552[c]
USER_DATA 4 flags 0-16[c]
NO_OVERFLOW_SIMPLE 0 in->f_path.d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.dentry->d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.moved->d_inode->i_size
NO_OVERFLOW_SIMPLE 2 pipe->max_usage
NO_OVERFLOW_SIMPLE 2 pipe->nr_accounted
NO_OVERFLOW_SIMPLE 2 pipe->ring_size
NO_OVERFLOW_SIMPLE 3 len
USER_PTR 1 ppos

fs/splice.c do_splice_read() -> (struct file_operations)->splice_read()

Type Parameter Key Value
PARAM_VALUE 0 in 4096-ptr_max
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_inode->i_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_mapping 4096-ptr_max
PARAM_VALUE 0 in->f_mapping->host 4096-ptr_max
PARAM_VALUE 0 in->f_op 4096-ptr_max
PARAM_VALUE 0 in->f_op->splice_read 1-u64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->encode_fh 0,2,1398972869330624512,1616549510479982592,2037984473558433792,2776440803454029824,3228746867770966016,3502492669594062848,3526768263295340544,3559173554394271744,5000850239487131648,5583386343686406144,5817357685191483392-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->fh_to_dentry 0,8684,447817974243774464,687732489194512384,742201802719268864,868497899885588480,1471448175530500096,2021658383390310400,2445877819203563520,2512819722689847296,2649270699546726400,2761259683714371584,2893332316235677696-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->fh_to_parent 0,4672,148606482432692224,436469935444291584,457356038048772096,467281172929331200,529780027764285440,1092893949038768128,1556959531105513472,1608953577475584000,1649536479961075712,2404761408063094784,2970908329832960000-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->host->i_sb->s_export_op->get_parent 0,8931,264940071972966400,291591359766798336,565128213429456896,893189740598853632,1241177127089143808,1474696885321834496,1812477326828269568,1893665921928286208,2210088671756947456,2437012291923775488,2483979068402987008-s64max
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->i_mmap_rwsem.first_waiter->handoff_set 0-1
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_mapping->i_mmap_rwsem.first_waiter->type 0-1
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->empty_dir 0,86,661756434209751040,4392966320616476672,5234023279986843648,8614756098313990144
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->get_context 0,706,17350455714160640,4513809449498124288,5149251875611672576,7067778626864828416
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->inode_info_offs 1632,1640,1720,1808,1816,2632,2640,2648,2704,2712
PARAM_VALUE 0 in->f_path.dentry->d_inode->i_sb->s_cop->set_context 0,67,317457138841939968,3250154607523569664,5979066299606671360,6756104566897242112
PARAM_VALUE 1 ppos 4096-ptr_max
PARAM_VALUE 2 pipe 4096-ptr_max
PARAM_VALUE 3 len 0-2147479552
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 0 in s32min,(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
BUF_SIZE 2 pipe s32min-(-1),1-s32max
CAPPED_DATA 3 len 1
CAPPED_DATA 3 len 1
DATA_SOURCE 0 in $0
DATA_SOURCE 1 ppos $1
DATA_SOURCE 2 pipe $2
DATA_SOURCE 3 len $3 [m]
DATA_SOURCE 4 flags $4
FUZZY_MAX 3 len 2147479552
CONTAINER 0 -184-80+0 $(-1)
BIT_INFO 0 in->f_flags 0x0,0xffffbfff
BIT_INFO 0 in->f_mode 0x1,0xffffffff
BIT_INFO 3 len 0x0,0xffffffff
NOSPEC 1 *ppos
NOSPEC 3 len
RX_PATH
TASK_NOT_RUNNING
USER_DATA 1 *ppos 0-15442450941
USER_DATA 3 len 1-2147479552[c]
USER_DATA 4 flags 0-16[c]
NO_OVERFLOW_SIMPLE 0 in->f_path.d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.dentry->d_inode->i_size
NO_OVERFLOW_SIMPLE 0 in->f_path.moved->d_inode->i_size
NO_OVERFLOW_SIMPLE 2 pipe->max_usage
NO_OVERFLOW_SIMPLE 2 pipe->nr_accounted
NO_OVERFLOW_SIMPLE 2 pipe->ring_size
NO_OVERFLOW_SIMPLE 3 len
USER_PTR 1 ppos