showframe package exceeds few points in right side

My tags are follows:

\documentclass{book}

\usepackage{lipsum}

\usepackage{showframe}

\makeatletter
\renewcommand\normalsize{%
\@setfontsize\normalsize{10.9}{14}%
\abovedisplayskip 7\p@ plus2\p@ %
\abovedisplayshortskip \z@ \@plus3\p@%
\belowdisplayshortskip 3.5\p@%
\belowdisplayskip 7\p@ plus2\p@%
\let\@listi\@listI}%
\normalsize%
\let\@bls\baselineskip%
\p@=1bp%%%
\makeatother

\begin{document}

\lipsum[1-2]

\end{document}


And the output shows as:

Hope the command \p@=1bp caused the error, but suggest that how to fix this including this tag too.

• Why on earth do you want to confuse all measures by setting pt sometimes equal to bp or whatever else the line does should do? – Ulrike Fischer Aug 20 '18 at 6:46
• @UlrikeFischer This tag I purposely used to get the font size exactly in PDF, I know type1cm.sty did that trick, but that was not applicable if we use other fonts like Times, Palatino, etc. – MadyYuvi Aug 20 '18 at 8:28
• Sorry this is madness. It means that 10pt has a different length than 10p@ and will break lots of packages. – Ulrike Fischer Aug 20 '18 at 8:34
• \usepackage[pass,showframe]{geometry} does not suffer the same issue. – Steven B. Segletes Aug 28 '18 at 20:22