Hard to say without your full code, but a few comments:
You are using an empty prototype with sub getfiles() - why?
Where are your variables coming from? use warnings; use strict
Are you capturing the reference being returned correctly?

The following works for me:

#!/usr/bin/perl 
use strict;
use warnings;  

sub getfiles
{
  my ($logSite) = @_;
  
  my @uploads;
  
  opendir DIR,$logSite or die "Unable to open Directory, please try ag
+ain";
  
  foreach my $pattern (@ARGV)
  {
    push (@uploads, grep /$pattern/, readdir(DIR));
  }
  
  closedir DIR;
   
  return \@uploads;
}

my $ref = getfiles('.');

print "@$ref\n";
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