Dear Igor,
We tried your test source code, still we are getting following error.
Please do needful.
root@phyboard-segin-imx6ul-1:~# ./a.out
---- Running < ./a.out > test ----
[ 44.166807] Unhandled fault: page domain fault (0x01b) at 0xbeabaca4
[ 44.173213] pgd = dd8b0000
[ 44.175951] [beabaca4] *pgd=9d828835, *pte=9c85275f, *ppte=9c852c7f
[ 44.182341] Internal error: : 1b [#1] SMP ARM
[ 44.186723] Modules linked in: evbug
[ 44.190386] CPU: 0 PID: 241 Comm: a.out Not tainted 4.8.0-phyBOARD-Segin-i.MX6UL-ALPHA1 #6
[ 44.198673] Hardware name: Freescale i.MX6 Ultralite (Device Tree)
[ 44.204880] task: dde03c00 task.stack: dd8d6000
[ 44.209451] PC is at sim_ioctl+0xb9c/0x1094
[ 44.213664] LR is at 0x0
[ 44.216226] pc : [<c069ac2c>] lr : [<00000000>] psr: 600e0013
[ 44.216226] sp : dd8d7ed0 ip : 0000001c fp : dd8d7efc
[ 44.227732] r10: 00000000 r9 : dd8d6000 r8 : 00000003
[ 44.232981] r7 : 00000051 r6 : beabaca0 r5 : 00000000 r4 : ddcd4410
[ 44.239535] r3 : dd8d6000 r2 : 00000000 r1 : 00000000 r0 : 00000000
[ 44.246090] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 44.253250] Control: 10c5387d Table: 9d8b006a DAC: 00000051
[ 44.259021] Process a.out (pid: 241, stack limit = 0xdd8d6210)
[ 44.264878] Stack: (0xdd8d7ed0 to 0xdd8d8000)
[ 44.269270] 7ec0: 200e0013 00000000 beabaca0 ddcd9918
[ 44.277482] 7ee0: dddc0b40 c02318dc 00000003 dd8d6000 dd8d7f7c dd8d7f00 c0230ed8 c069a09c
[ 44.285697] 7f00: dddc0b48 c022d5b4 00000020 dde1e000 00000020 dde1e000 dddc0b40 ddcd9918
[ 44.293910] 7f20: dddc0b48 00000000 dd8d7f4c dd8d7f38 c022d5b4 c0215128 00000003 00000020
[ 44.302124] 7f40: dd8d7f94 dd8d7f50 c021c774 c022d55c 00000000 dddc0b40 00000003 dddc0b40
[ 44.310336] 7f60: 800cc002 beabaca0 dd8d6000 00000000 dd8d7fa4 dd8d7f80 c02318dc c0230e48
[ 44.318550] 7f80: 00010c38 00000000 000104fc 00000036 c0107fc4 dd8d6000 00000000 dd8d7fa8
[ 44.326762] 7fa0: c0107e20 c02318ac 00010c38 00000000 00000003 800cc002 beabaca0 beabaca0
[ 44.334974] 7fc0: 00010c38 00000000 000104fc 00000036 00000000 00000000 b6fb8000 beabacbc
[ 44.343185] 7fe0: 00021018 beabab9c 00010a98 b6f14fec 000e0010 00000003 00000000 00000000
[ 44.351381] Backtrace:
[ 44.353899] [<c069a090>] (sim_ioctl) from [<c0230ed8>] (do_vfs_ioctl+0x9c/0xa64)
[ 44.361321] r9:dd8d6000 r8:00000003 r7:c02318dc r6:dddc0b40 r5:ddcd9918 r4:beabaca0
[ 44.369238] [<c0230e3c>] (do_vfs_ioctl) from [<c02318dc>] (SyS_ioctl+0x3c/0x64)
[ 44.376569] r10:00000000 r9:dd8d6000 r8:beabaca0 r7:800cc002 r6:dddc0b40 r5:00000003
[ 44.384558] r4:dddc0b40
[ 44.387157] [<c02318a0>] (SyS_ioctl) from [<c0107e20>] (ret_fast_syscall+0x0/0x1c)
[ 44.394747] r9:dd8d6000 r8:c0107fc4 r7:00000036 r6:000104fc r5:00000000 r4:00010c38
[ 44.402664] Code: 1affff5a e1a0300d e3c33d7f e3c3303f (e5960004)
[ 44.408794] ---[ end trace 8a6b76174727e96d ]---
Segmentation fault