I want to list files and directories under "/proc" in Android. When running as my application process, many files are not readable.
If I list the directory as the shell user I get the following output:
shell@flounder:/ $ whoami shell shell@flounder:/ $ /system/bin/toolbox ls -l /proc dr-xr-xr-x root root 2015-09-12 03:30 1 dr-xr-xr-x root root 2015-09-12 03:31 10 dr-xr-xr-x root root 2015-09-12 03:31 101 dr-xr-xr-x shell shell 2015-09-15 03:24 10196 dr-xr-xr-x root root 2015-09-12 03:31 102 dr-xr-xr-x root root 2015-09-12 03:31 103 dr-xr-xr-x root root 2015-09-12 03:31 104 dr-xr-xr-x u0_a15 u0_a15 2015-09-14 07:37 10451 dr-xr-xr-x root root 2015-09-12 03:31 105 dr-xr-xr-x wifi wifi 2015-09-14 08:53 10570 dr-xr-xr-x root root 2015-09-12 03:31 106 dr-xr-xr-x root root 2015-09-12 03:31 107 dr-xr-xr-x root root 2015-09-12 03:31 108 dr-xr-xr-x root root 2015-09-12 03:31 11 dr-xr-xr-x root root 2015-09-12 03:31 110 dr-xr-xr-x root root 2015-09-12 03:31 111 dr-xr-xr-x root root 2015-09-12 03:31 112 dr-xr-xr-x root root 2015-09-12 03:31 113 dr-xr-xr-x root root 2015-09-12 03:31 114 dr-xr-xr-x root root 2015-09-12 03:31 115 dr-xr-xr-x root root 2015-09-12 03:31 116 dr-xr-xr-x root root 2015-09-12 03:31 117 dr-xr-xr-x root root 2015-09-12 03:31 118 dr-xr-xr-x root root 2015-09-12 03:31 119 dr-xr-xr-x u0_a26 u0_a26 2015-09-12 03:31 1193 dr-xr-xr-x root root 2015-09-12 03:31 12 dr-xr-xr-x root root 2015-09-12 03:31 120 dr-xr-xr-x u0_a57 u0_a57 2015-09-12 03:31 1209 dr-xr-xr-x root root 2015-09-12 03:31 121 dr-xr-xr-x root root 2015-09-12 03:31 122 dr-xr-xr-x nfc nfc 2015-09-12 03:31 1227 dr-xr-xr-x root root 2015-09-12 03:31 123 dr-xr-xr-x radio radio 2015-09-12 03:31 1239 dr-xr-xr-x root root 2015-09-12 03:31 124 dr-xr-xr-x u0_a26 u0_a26 2015-09-12 03:31 1246 dr-xr-xr-x root root 2015-09-12 03:31 125 dr-xr-xr-x root root 2015-09-12 03:31 126 dr-xr-xr-x root root 2015-09-12 03:31 127 dr-xr-xr-x root root 2015-09-12 03:30 128 dr-xr-xr-x root root 2015-09-12 03:31 13 dr-xr-xr-x u0_a26 u0_a26 2015-09-12 03:31 1305 dr-xr-xr-x root root 2015-09-12 03:30 132 dr-xr-xr-x root root 2015-09-12 03:31 134 dr-xr-xr-x u0_a86 u0_a86 2015-09-14 07:16 1343 dr-xr-xr-x root root 2015-09-12 03:31 135 dr-xr-xr-x root root 2015-09-12 03:31 136 dr-xr-xr-x root root 2015-09-12 03:31 137 dr-xr-xr-x root root 2015-09-12 03:31 138 dr-xr-xr-x root root 2015-09-12 03:31 139 dr-xr-xr-x root root 2015-09-12 03:31 14 dr-xr-xr-x root root 2015-09-12 03:31 140 dr-xr-xr-x root root 2015-09-12 03:31 141 dr-xr-xr-x root root 2015-09-12 03:31 142 dr-xr-xr-x root root 2015-09-12 03:31 143 dr-xr-xr-x root root 2015-09-12 03:31 144 dr-xr-xr-x root root 2015-09-12 03:31 145 dr-xr-xr-x root root 2015-09-12 03:31 149 dr-xr-xr-x root root 2015-09-12 03:31 150 dr-xr-xr-x logd logd 2015-09-12 03:30 153 dr-xr-xr-x root root 2015-09-12 03:30 155 dr-xr-xr-x root root 2015-09-12 03:31 16 dr-xr-xr-x root root 2015-09-12 03:31 160 dr-xr-xr-x root root 2015-09-12 03:30 163 dr-xr-xr-x root root 2015-09-12 03:30 164 dr-xr-xr-x system system 2015-09-12 03:30 165 dr-xr-xr-x u0_a9 u0_a9 2015-09-12 03:31 1652 dr-xr-xr-x system graphics 2015-09-12 03:30 166 dr-xr-xr-x root root 2015-09-12 03:31 17 dr-xr-xr-x system system 2015-09-14 05:30 18227 dr-xr-xr-x root root 2015-09-12 03:31 188 dr-xr-xr-x root root 2015-09-12 03:31 192 dr-xr-xr-x root root 2015-09-12 03:31 193 dr-xr-xr-x root root 2015-09-12 03:31 194 dr-xr-xr-x root root 2015-09-12 03:31 195 dr-xr-xr-x root root 2015-09-12 03:31 2 dr-xr-xr-x root root 2015-09-12 03:31 20 dr-xr-xr-x u0_a19 u0_a19 2015-09-14 05:36 20564 dr-xr-xr-x root root 2015-09-12 03:31 207 dr-xr-xr-x u0_a45 u0_a45 2015-09-15 03:00 20763 dr-xr-xr-x root root 2015-09-12 03:31 208 dr-xr-xr-x root root 2015-09-12 03:31 21 dr-xr-xr-x shell shell 2015-09-12 03:31 210 dr-xr-xr-x root root 2015-09-12 03:31 215 dr-xr-xr-x root root 2015-09-12 03:31 216 dr-xr-xr-x root root 2015-09-12 03:31 217 dr-xr-xr-x drm drm 2015-09-12 03:31 218 dr-xr-xr-x media audio 2015-09-12 03:31 219 dr-xr-xr-x root root 2015-09-12 03:31 22 dr-xr-xr-x root root 2015-09-12 03:31 220 dr-xr-xr-x keystore keystore 2015-09-12 03:31 222 dr-xr-xr-x system system 2015-09-12 03:31 223 dr-xr-xr-x root root 2015-09-12 03:31 224 dr-xr-xr-x root root 2015-09-12 03:31 225 dr-xr-xr-x shell shell 2015-09-15 03:15 2258 dr-xr-xr-x system root 2015-09-12 03:31 226 dr-xr-xr-x gps system 2015-09-12 03:31 227 dr-xr-xr-x u0_a67 u0_a67 2015-09-15 03:15 2270 dr-xr-xr-x root root 2015-09-12 03:31 23 dr-xr-xr-x root root 2015-09-12 03:31 24 dr-xr-xr-x root root 2015-09-12 03:31 2428 dr-xr-xr-x root root 2015-09-15 03:05 24353 dr-xr-xr-x root root 2015-09-12 03:31 25 dr-xr-xr-x root root 2015-09-15 03:11 25597 dr-xr-xr-x root root 2015-09-12 03:31 26 dr-xr-xr-x root root 2015-09-15 03:11 26671 dr-xr-xr-x root root 2015-09-12 03:31 27 dr-xr-xr-x u0_a84 u0_a84 2015-09-15 03:15 2738 dr-xr-xr-x root root 2015-09-12 03:31 28 dr-xr-xr-x root root 2015-09-12 03:31 29 dr-xr-xr-x root root 2015-09-15 03:11 29355 dr-xr-xr-x root root 2015-09-15 03:16 2958 dr-xr-xr-x root root 2015-09-12 03:31 3 dr-xr-xr-x root root 2015-09-12 03:31 30 dr-xr-xr-x u0_a5 u0_a5 2015-09-15 03:10 30095 dr-xr-xr-x u0_a18 u0_a18 2015-09-15 03:11 30266 dr-xr-xr-x u0_a40 u0_a40 2015-09-15 03:11 30290 dr-xr-xr-x system system 2015-09-15 03:11 30333 dr-xr-xr-x u0_a37 u0_a37 2015-09-15 03:11 30382 dr-xr-xr-x u0_a77 u0_a77 2015-09-15 03:11 30420 dr-xr-xr-x u0_a61 u0_a61 2015-09-15 03:11 30458 dr-xr-xr-x root root 2015-09-14 09:56 30729 dr-xr-xr-x u0_a4 u0_a4 2015-09-14 11:12 30994 dr-xr-xr-x root root 2015-09-12 03:31 31 dr-xr-xr-x u0_a9 u0_a9 2015-09-14 13:31 31453 dr-xr-xr-x shell shell 2015-09-15 03:12 31844 dr-xr-xr-x root root 2015-09-12 03:31 32 dr-xr-xr-x u0_a6 u0_a6 2015-09-15 01:13 32176 dr-xr-xr-x root root 2015-09-15 02:34 32422 dr-xr-xr-x root root 2015-09-15 03:13 32476 dr-xr-xr-x shell shell 2015-09-15 02:39 32552 dr-xr-xr-x root root 2015-09-12 03:31 33 dr-xr-xr-x root root 2015-09-12 03:31 47 dr-xr-xr-x root root 2015-09-12 03:31 48 dr-xr-xr-x root root 2015-09-12 03:31 49 dr-xr-xr-x root root 2015-09-12 03:31 5 dr-xr-xr-x root root 2015-09-12 03:31 50 dr-xr-xr-x system system 2015-09-12 03:31 590 dr-xr-xr-x root root 2015-09-12 03:31 64 dr-xr-xr-x root root 2015-09-12 03:31 65 dr-xr-xr-x root root 2015-09-12 03:31 66 dr-xr-xr-x media_rw media_rw 2015-09-12 03:31 666 dr-xr-xr-x root root 2015-09-12 03:31 67 dr-xr-xr-x root root 2015-09-12 03:31 68 dr-xr-xr-x root root 2015-09-12 03:31 69 dr-xr-xr-x u0_a24 u0_a24 2015-09-12 03:31 694 dr-xr-xr-x root root 2015-09-12 03:31 7 dr-xr-xr-x root root 2015-09-12 03:31 70 dr-xr-xr-x root root 2015-09-12 03:31 71 dr-xr-xr-x u0_a88 u0_a88 2015-09-14 06:14 7104 dr-xr-xr-x root root 2015-09-12 03:31 72 dr-xr-xr-x u0_a88 u0_a88 2015-09-14 06:15 7217 dr-xr-xr-x root root 2015-09-15 03:21 7221 dr-xr-xr-x root root 2015-09-12 03:31 73 dr-xr-xr-x root root 2015-09-12 03:31 74 dr-xr-xr-x root root 2015-09-15 03:21 7487 dr-xr-xr-x root root 2015-09-12 03:31 75 dr-xr-xr-x root root 2015-09-12 03:31 76 dr-xr-xr-x root root 2015-09-12 03:31 77 dr-xr-xr-x root root 2015-09-12 03:31 78 dr-xr-xr-x root root 2015-09-12 03:31 79 dr-xr-xr-x root root 2015-09-12 03:31 8 dr-xr-xr-x root root 2015-09-12 03:31 81 dr-xr-xr-x root root 2015-09-12 03:31 82 dr-xr-xr-x u0_a14 u0_a14 2015-09-15 02:45 8250 dr-xr-xr-x root root 2015-09-12 03:31 83 dr-xr-xr-x root root 2015-09-12 03:31 84 dr-xr-xr-x root root 2015-09-12 03:31 85 dr-xr-xr-x u0_a53 u0_a53 2015-09-13 11:39 8517 dr-xr-xr-x root root 2015-09-12 03:31 87 dr-xr-xr-x root root 2015-09-12 03:31 88 dr-xr-xr-x root root 2015-09-12 03:31 89 dr-xr-xr-x root root 2015-09-12 03:31 9 dr-xr-xr-x root root 2015-09-12 03:31 90 dr-xr-xr-x u0_a9 u0_a9 2015-09-12 03:31 903 dr-xr-xr-x root root 2015-09-12 03:31 91 dr-xr-xr-x u0_a9 u0_a9 2015-09-13 11:45 9159 dr-xr-xr-x root root 2015-09-12 03:31 93 dr-xr-xr-x u0_a66 u0_a66 2015-09-14 08:52 9356 dr-xr-xr-x root root 2015-09-12 03:31 94 dr-xr-xr-x root root 2015-09-12 03:31 95 dr-xr-xr-x root root 2015-09-12 03:31 97 dr-xr-xr-x root root 2015-09-12 03:31 98 dr-xr-xr-x root root 2015-09-12 03:31 99 dr-xr-xr-x root root 2015-09-15 03:24 asound dr-xr-xr-x root root 2015-09-15 03:24 bluetooth -r--r--r-- root root 0 2015-09-15 03:24 buddyinfo dr-xr-xr-x root root 2015-09-15 03:24 bus -r--r--r-- root root 0 2015-09-15 03:24 cgroups -r--r----- root radio 0 2015-09-15 03:24 cmdline -r--r--r-- root root 0 2015-09-15 03:24 consoles -r--r--r-- root root 0 2015-09-15 03:24 cpuinfo -r--r--r-- root root 0 2015-09-15 03:24 crypto dr-xr-xr-x root root 2015-09-15 03:24 device-tree -r--r--r-- root root 0 2015-09-15 03:24 devices -r--r--r-- root root 0 2015-09-15 03:24 diskstats dr-xr-xr-x root root 2015-09-15 03:24 driver -r--r--r-- root root 0 2015-09-15 03:24 execdomains -r--r--r-- root root 0 2015-09-15 03:24 fb -r--r--r-- root root 0 2015-09-15 03:24 filesystems dr-xr-xr-x root root 2015-09-15 03:24 fs -r--r--r-- root root 0 2015-09-15 03:24 interrupts -r--r--r-- root root 0 2015-09-15 03:24 iomem -r--r--r-- root root 0 2015-09-15 03:24 ioports dr-xr-xr-x root root 2015-09-15 03:24 irq -r--r--r-- root root 0 2015-09-15 03:24 kallsyms -r--r----- root system 0 2015-09-12 03:30 kmsg -r-------- root root 0 2015-09-15 03:24 kpagecount -r-------- root root 0 2015-09-15 03:24 kpageflags -r--r--r-- root root 0 2015-09-15 03:24 loadavg -r--r--r-- root root 0 2015-09-15 03:24 locks -r--r--r-- root root 0 2015-09-15 03:24 meminfo -r--r--r-- root root 0 2015-09-15 03:24 misc lrwxrwxrwx root root 2015-09-15 03:24 mounts -> self/mounts lrwxrwxrwx root root 2015-09-15 03:24 net -> self/net -r--r--r-- root root 0 2015-09-15 03:24 pagetypeinfo -r--r--r-- root root 0 2015-09-15 03:24 partitions dr-xr-xr-x root root 2015-09-15 03:24 quadd -r--r--r-- root root 0 2015-09-15 03:24 sched_debug -r--r--r-- root root 0 2015-09-15 03:24 schedstat dr-xr-xr-x root root 2015-09-15 03:24 scsi lrwxrwxrwx root root 1969-12-31 16:00 self -> 10196 -r--r----- root log 0 2015-09-15 03:24 slabinfo -r--r--r-- root root 0 2015-09-15 03:24 softirqs -r--r--r-- root root 0 2015-09-15 03:24 stat -r--r--r-- root root 0 2015-09-15 03:24 swaps dr-xr-xr-x root root 2015-09-14 06:13 sys lstat '/proc/sysrq-trigger' failed: Permission denied dr-xr-xr-x root root 2015-09-15 03:24 sysvipc -r--r--r-- root root 0 2015-09-15 03:24 timer_list -rw-r--r-- root root 0 2015-09-15 03:24 timer_stats dr-xr-xr-x root root 2015-09-15 03:24 tty dr-xr-xr-x root root 2015-09-15 03:24 uid_cputime dr-xr-xr-x root root 2015-09-15 03:24 uid_stat -r--r--r-- root root 0 2015-09-15 03:24 uptime -r--r--r-- root root 0 2015-09-15 03:24 version -r--r----- root log 0 2015-09-15 03:24 vmallocinfo -r--r--r-- root root 0 2015-09-15 03:24 vmstat -r--r--r-- root root 0 2015-09-15 03:24 zoneinfo
If I list the the directory as my app process (using run-as [PACKAGE_NAME]):
shell@flounder:/ $ run-as my.packagename shell@flounder:/data/data/my.packagename $ whoami u0_a84 shell@flounder:/data/data/my.packagename $ /system/bin/toolbox ls -l /proc lstat '/proc/1' failed: Permission denied lstat '/proc/10' failed: Permission denied lstat '/proc/101' failed: Permission denied lstat '/proc/102' failed: Permission denied lstat '/proc/103' failed: Permission denied lstat '/proc/104' failed: Permission denied dr-xr-xr-x u0_a15 u0_a15 2015-09-14 07:37 10451 lstat '/proc/105' failed: Permission denied lstat '/proc/10570' failed: Permission denied lstat '/proc/106' failed: Permission denied lstat '/proc/107' failed: Permission denied lstat '/proc/108' failed: Permission denied lstat '/proc/11' failed: Permission denied lstat '/proc/110' failed: Permission denied lstat '/proc/111' failed: Permission denied lstat '/proc/112' failed: Permission denied lstat '/proc/113' failed: Permission denied lstat '/proc/114' failed: Permission denied lstat '/proc/115' failed: Permission denied dr-xr-xr-x u0_a84 u0_a84 2015-09-15 03:26 11513 lstat '/proc/116' failed: Permission denied lstat '/proc/117' failed: Permission denied lstat '/proc/11719' failed: Permission denied lstat '/proc/118' failed: Permission denied lstat '/proc/119' failed: Permission denied dr-xr-xr-x u0_a26 u0_a26 2015-09-12 03:31 1193 lstat '/proc/12' failed: Permission denied lstat '/proc/120' failed: Permission denied dr-xr-xr-x u0_a57 u0_a57 2015-09-12 03:31 1209 lstat '/proc/121' failed: Permission denied lstat '/proc/122' failed: Permission denied lstat '/proc/1227' failed: Permission denied lstat '/proc/123' failed: Permission denied lstat '/proc/1239' failed: Permission denied lstat '/proc/124' failed: Permission denied dr-xr-xr-x u0_a26 u0_a26 2015-09-12 03:31 1246 lstat '/proc/125' failed: Permission denied lstat '/proc/126' failed: Permission denied lstat '/proc/12696' failed: Permission denied lstat '/proc/127' failed: Permission denied lstat '/proc/128' failed: Permission denied lstat '/proc/13' failed: Permission denied dr-xr-xr-x u0_a26 u0_a26 2015-09-12 03:31 1305 lstat '/proc/132' failed: Permission denied lstat '/proc/134' failed: Permission denied dr-xr-xr-x u0_a86 u0_a86 2015-09-14 07:16 1343 lstat '/proc/135' failed: Permission denied lstat '/proc/136' failed: Permission denied lstat '/proc/137' failed: Permission denied lstat '/proc/138' failed: Permission denied lstat '/proc/139' failed: Permission denied lstat '/proc/14' failed: Permission denied lstat '/proc/140' failed: Permission denied dr-xr-xr-x u0_a84 u0_a84 2015-09-15 03:29 14005 lstat '/proc/141' failed: Permission denied lstat '/proc/142' failed: Permission denied lstat '/proc/143' failed: Permission denied lstat '/proc/144' failed: Permission denied lstat '/proc/145' failed: Permission denied lstat '/proc/149' failed: Permission denied lstat '/proc/150' failed: Permission denied lstat '/proc/153' failed: Permission denied lstat '/proc/155' failed: Permission denied lstat '/proc/16' failed: Permission denied lstat '/proc/160' failed: Permission denied lstat '/proc/163' failed: Permission denied lstat '/proc/164' failed: Permission denied lstat '/proc/165' failed: Permission denied dr-xr-xr-x u0_a9 u0_a9 2015-09-12 03:31 1652 lstat '/proc/166' failed: Permission denied lstat '/proc/17' failed: Permission denied lstat '/proc/18227' failed: Permission denied lstat '/proc/188' failed: Permission denied lstat '/proc/192' failed: Permission denied lstat '/proc/193' failed: Permission denied lstat '/proc/194' failed: Permission denied lstat '/proc/195' failed: Permission denied lstat '/proc/2' failed: Permission denied lstat '/proc/20' failed: Permission denied dr-xr-xr-x u0_a19 u0_a19 2015-09-14 05:36 20564 lstat '/proc/207' failed: Permission denied dr-xr-xr-x u0_a45 u0_a45 2015-09-15 03:00 20763 lstat '/proc/208' failed: Permission denied lstat '/proc/21' failed: Permission denied lstat '/proc/210' failed: Permission denied lstat '/proc/215' failed: Permission denied lstat '/proc/216' failed: Permission denied lstat '/proc/217' failed: Permission denied lstat '/proc/218' failed: Permission denied lstat '/proc/219' failed: Permission denied lstat '/proc/22' failed: Permission denied lstat '/proc/220' failed: Permission denied lstat '/proc/222' failed: Permission denied lstat '/proc/223' failed: Permission denied lstat '/proc/224' failed: Permission denied lstat '/proc/225' failed: Permission denied lstat '/proc/2258' failed: Permission denied lstat '/proc/226' failed: Permission denied lstat '/proc/227' failed: Permission denied dr-xr-xr-x u0_a67 u0_a67 2015-09-15 03:15 2270 lstat '/proc/23' failed: Permission denied lstat '/proc/24' failed: Permission denied lstat '/proc/2428' failed: Permission denied lstat '/proc/24353' failed: Permission denied lstat '/proc/25' failed: Permission denied lstat '/proc/25597' failed: Permission denied lstat '/proc/26' failed: Permission denied lstat '/proc/26671' failed: Permission denied lstat '/proc/27' failed: Permission denied dr-xr-xr-x u0_a84 u0_a84 2015-09-15 03:15 2738 lstat '/proc/28' failed: Permission denied lstat '/proc/29' failed: Permission denied lstat '/proc/3' failed: Permission denied lstat '/proc/30' failed: Permission denied lstat '/proc/30095' failed: Permission denied dr-xr-xr-x u0_a18 u0_a18 2015-09-15 03:11 30266 dr-xr-xr-x u0_a40 u0_a40 2015-09-15 03:11 30290 lstat '/proc/30333' failed: Permission denied dr-xr-xr-x u0_a37 u0_a37 2015-09-15 03:11 30382 dr-xr-xr-x u0_a77 u0_a77 2015-09-15 03:11 30420 dr-xr-xr-x u0_a61 u0_a61 2015-09-15 03:11 30458 lstat '/proc/30729' failed: Permission denied dr-xr-xr-x u0_a4 u0_a4 2015-09-14 11:12 30994 lstat '/proc/31' failed: Permission denied dr-xr-xr-x u0_a9 u0_a9 2015-09-14 13:31 31453 lstat '/proc/31844' failed: Permission denied lstat '/proc/32' failed: Permission denied dr-xr-xr-x u0_a6 u0_a6 2015-09-15 01:13 32176 lstat '/proc/32422' failed: Permission denied lstat '/proc/32476' failed: Permission denied lstat '/proc/32552' failed: Permission denied lstat '/proc/33' failed: Permission denied lstat '/proc/47' failed: Permission denied lstat '/proc/48' failed: Permission denied lstat '/proc/49' failed: Permission denied lstat '/proc/5' failed: Permission denied lstat '/proc/50' failed: Permission denied lstat '/proc/590' failed: Permission denied lstat '/proc/64' failed: Permission denied lstat '/proc/65' failed: Permission denied lstat '/proc/66' failed: Permission denied lstat '/proc/666' failed: Permission denied lstat '/proc/67' failed: Permission denied lstat '/proc/68' failed: Permission denied lstat '/proc/69' failed: Permission denied lstat '/proc/694' failed: Permission denied lstat '/proc/7' failed: Permission denied lstat '/proc/70' failed: Permission denied lstat '/proc/71' failed: Permission denied dr-xr-xr-x u0_a88 u0_a88 2015-09-14 06:14 7104 lstat '/proc/72' failed: Permission denied dr-xr-xr-x u0_a88 u0_a88 2015-09-14 06:15 7217 lstat '/proc/7221' failed: Permission denied lstat '/proc/73' failed: Permission denied lstat '/proc/74' failed: Permission denied lstat '/proc/7487' failed: Permission denied lstat '/proc/75' failed: Permission denied lstat '/proc/76' failed: Permission denied lstat '/proc/77' failed: Permission denied lstat '/proc/78' failed: Permission denied lstat '/proc/79' failed: Permission denied lstat '/proc/8' failed: Permission denied lstat '/proc/81' failed: Permission denied lstat '/proc/82' failed: Permission denied dr-xr-xr-x u0_a14 u0_a14 2015-09-15 02:45 8250 lstat '/proc/83' failed: Permission denied lstat '/proc/84' failed: Permission denied lstat '/proc/85' failed: Permission denied dr-xr-xr-x u0_a53 u0_a53 2015-09-13 11:39 8517 lstat '/proc/87' failed: Permission denied lstat '/proc/88' failed: Permission denied lstat '/proc/89' failed: Permission denied lstat '/proc/9' failed: Permission denied lstat '/proc/90' failed: Permission denied dr-xr-xr-x u0_a9 u0_a9 2015-09-12 03:31 903 lstat '/proc/91' failed: Permission denied dr-xr-xr-x u0_a9 u0_a9 2015-09-13 11:45 9159 lstat '/proc/93' failed: Permission denied dr-xr-xr-x u0_a66 u0_a66 2015-09-14 08:52 9356 lstat '/proc/94' failed: Permission denied lstat '/proc/95' failed: Permission denied lstat '/proc/97' failed: Permission denied lstat '/proc/98' failed: Permission denied lstat '/proc/99' failed: Permission denied dr-xr-xr-x root root 2015-09-15 03:29 asound dr-xr-xr-x root root 2015-09-15 03:29 bluetooth -r--r--r-- root root 0 2015-09-15 03:29 buddyinfo dr-xr-xr-x root root 2015-09-15 03:29 bus -r--r--r-- root root 0 2015-09-15 03:29 cgroups -r--r----- root radio 0 2015-09-15 03:29 cmdline -r--r--r-- root root 0 2015-09-15 03:29 consoles -r--r--r-- root root 0 2015-09-15 03:29 cpuinfo -r--r--r-- root root 0 2015-09-15 03:29 crypto dr-xr-xr-x root root 2015-09-15 03:29 device-tree -r--r--r-- root root 0 2015-09-15 03:29 devices -r--r--r-- root root 0 2015-09-15 03:29 diskstats dr-xr-xr-x root root 2015-09-15 03:29 driver -r--r--r-- root root 0 2015-09-15 03:29 execdomains -r--r--r-- root root 0 2015-09-15 03:29 fb -r--r--r-- root root 0 2015-09-15 03:29 filesystems dr-xr-xr-x root root 2015-09-15 03:29 fs -r--r--r-- root root 0 2015-09-15 03:29 interrupts -r--r--r-- root root 0 2015-09-15 03:29 iomem -r--r--r-- root root 0 2015-09-15 03:29 ioports dr-xr-xr-x root root 2015-09-15 03:29 irq -r--r--r-- root root 0 2015-09-15 03:29 kallsyms -r--r----- root system 0 2015-09-12 03:30 kmsg -r-------- root root 0 2015-09-15 03:29 kpagecount -r-------- root root 0 2015-09-15 03:29 kpageflags -r--r--r-- root root 0 2015-09-15 03:29 loadavg -r--r--r-- root root 0 2015-09-15 03:29 locks -r--r--r-- root root 0 2015-09-15 03:29 meminfo -r--r--r-- root root 0 2015-09-15 03:29 misc lrwxrwxrwx root root 2015-09-15 03:29 mounts -> self/mounts lrwxrwxrwx root root 2015-09-15 03:29 net -> self/net -r--r--r-- root root 0 2015-09-15 03:29 pagetypeinfo -r--r--r-- root root 0 2015-09-15 03:29 partitions dr-xr-xr-x root root 2015-09-15 03:29 quadd -r--r--r-- root root 0 2015-09-15 03:29 sched_debug -r--r--r-- root root 0 2015-09-15 03:29 schedstat dr-xr-xr-x root root 2015-09-15 03:29 scsi lrwxrwxrwx root root 1969-12-31 16:00 self -> 14005 -r--r----- root log 0 2015-09-15 03:29 slabinfo -r--r--r-- root root 0 2015-09-15 03:29 softirqs -r--r--r-- root root 0 2015-09-15 03:29 stat -r--r--r-- root root 0 2015-09-15 03:29 swaps dr-xr-xr-x root root 2015-09-14 06:13 sys lstat '/proc/sysrq-trigger' failed: Permission denied dr-xr-xr-x root root 2015-09-15 03:29 sysvipc -r--r--r-- root root 0 2015-09-15 03:29 timer_list -rw-r--r-- root root 0 2015-09-15 03:29 timer_stats dr-xr-xr-x root root 2015-09-15 03:29 tty dr-xr-xr-x root root 2015-09-15 03:29 uid_cputime dr-xr-xr-x root root 2015-09-15 03:29 uid_stat -r--r--r-- root root 0 2015-09-15 03:29 uptime -r--r--r-- root root 0 2015-09-15 03:29 version -r--r----- root log 0 2015-09-15 03:29 vmallocinfo -r--r--r-- root root 0 2015-09-15 03:29 vmstat -r--r--r-- root root 0 2015-09-15 03:29 zoneinfo
Obviously, the files that I received a “Permission denied” error on cannot be read using new java.io.File("/proc").listFiles(); either.
My question:
Why can’t my application process read these directories? The permissions give “other” users read access (“dr-xr-xr-x”).
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Answer
Android 5 and above use SELinux which uses two forms of access control. Traditional Linux uses a Discretionary Access Control List. The SE component also enforces a Mandatory Access Control List. The former is default allow, the latter is default deny.
You, or a process, only have access to an object if both sets of permissions allow you. Access is determined by SE contexts. Shell and app contexts have different permissions, and unfortunately there isn’t any known way to give an app shell context.
You can view Security Contexts using:
ls -Z
I don’t have a Marshmallow device to test, however what might give your app the necessary context is getting the usagestatsmanager permission. A user would have to enable it security settings, and I’m told Samsung devices don’t have the necessary menu. Shot in the dark mind you.
If you want to try it, see this question: How to check if “android.permission.PACKAGE_USAGE_STATS” permission is given?
This page might give you more info on permissions: https://su.chainfire.eu/#selinux