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.
Showing the changes to scripts (1 of 1 file). Show all
Unified · Split
| @@ -10,6 +10,14 @@ · 9 unmodified lines | |||
| 10 | # Use --debug to output path before parsing, this is useful to find files that | 10 | # Use --debug to output path before parsing, this is useful to find files that |
| 11 | # cause the script to choke. | 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 | use warnings; | 21 | use warnings; |
| 14 | use strict; | 22 | use strict; |
| 15 | use POSIX; | 23 | use POSIX; |
| @@ -472,6 +480,10 @@ sub walk · 456 unmodified lines | |||
| 472 | my $path = "$pwd/$file"; | 480 | my $path = "$pwd/$file"; |
| 473 | next if (-l $path); | 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$/)); | ||
| 486 | |||
| 475 | next if (skip($path)); | 487 | next if (skip($path)); |
| 476 | 488 | ||
| 477 | if (-d $path) { | 489 | if (-d $path) { |