When the system is idle it is likely that most files under /proc/PID will be identical for various processes. Scanning _all_ the PIDs under /proc is unnecessary and implies that we are thoroughly scanning /proc. This is _not_ the case because there may be ways userspace can trigger creation of /proc files that leak addresses but were not present during a scan. For these two reasons we should exclude all PID directories under /proc except '1/' Exclude all /proc/PID except /proc/1.
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| @@ -10,6 +10,14 @@ · 9 unmodified lines | ||
| 10 | 10 | # Use --debug to output path before parsing, this is useful to find files that |
| 11 | 11 | # cause the script to choke. |
| 12 | 12 | |
| 13 | +# | |
| 14 | +# When the system is idle it is likely that most files under /proc/PID will be | |
| 15 | +# identical for various processes. Scanning _all_ the PIDs under /proc is | |
| 16 | +# unnecessary and implies that we are thoroughly scanning /proc. This is _not_ | |
| 17 | +# the case because there may be ways userspace can trigger creation of /proc | |
| 18 | +# files that leak addresses but were not present during a scan. For these two | |
| 19 | +# reasons we exclude all PID directories under /proc except '1/' | |
| 20 | + | |
| 13 | 21 | use warnings; |
| 14 | 22 | use strict; |
| 15 | 23 | use POSIX; |
| @@ -472,6 +480,10 @@ sub walk · 456 unmodified lines | ||
| 472 | 480 | my $path = "$pwd/$file"; |
| 473 | 481 | next if (-l $path); |
| 474 | 482 | |
| 483 | + # skip /proc/PID except /proc/1 | |
| 484 | + next if (($path =~ /^\/proc\/[0-9]+$/) && | |
| 485 | + ($path !~ /^\/proc\/1$/)); | |
| 486 | + | |
| 475 | 487 | next if (skip($path)); |
| 476 | 488 | |
| 477 | 489 | if (-d $path) { |