diff options
Diffstat (limited to 'posts')
| -rw-r--r-- | posts/.dir-locals.el | 1 | ||||
| -rw-r--r-- | posts/Writeups for Dennis Yurichev's Reverse Engineering Challenges (#2-#11)/challenges-re-writeups-1.org | 42 |
2 files changed, 12 insertions, 31 deletions
diff --git a/posts/.dir-locals.el b/posts/.dir-locals.el index c7de0d6..4a56f9d 100644 --- a/posts/.dir-locals.el +++ b/posts/.dir-locals.el @@ -1,5 +1,6 @@ ((org-mode . ((org-html-doctype . "xhtml5") (org-html-html5-fancy . t) + (org-html-with-latex . 'verbatim) (org-export-with-toc . nil) (org-export-with-section-numbers . nil) (org-export-with-sub-superscripts . nil) diff --git a/posts/Writeups for Dennis Yurichev's Reverse Engineering Challenges (#2-#11)/challenges-re-writeups-1.org b/posts/Writeups for Dennis Yurichev's Reverse Engineering Challenges (#2-#11)/challenges-re-writeups-1.org index bb8f54d..6ea207c 100644 --- a/posts/Writeups for Dennis Yurichev's Reverse Engineering Challenges (#2-#11)/challenges-re-writeups-1.org +++ b/posts/Writeups for Dennis Yurichev's Reverse Engineering Challenges (#2-#11)/challenges-re-writeups-1.org @@ -223,10 +223,10 @@ f(31) = 27 #+END_SRC There's a pattern of exponential growth here -- every result occurs twice as -frequently as the previous result. Mathematically, this is $31 - [log_2(n)]$ -where the brackets represent the Greatest Integer Function ($f(x)$ returning the -largest integer less than or equal to $x$). This can be verified by comparing -the result of =f= to the following function for some test values: +frequently as the previous result. Mathematically, this is \(31 - [log_2(n)]\) +where the brackets represent the Greatest Integer Function (\(f(x)\) returning +the largest integer less than or equal to \(x\)). This can be verified by +comparing the result of =f= to the following function for some test values: #+BEGIN_SRC c :hl_lines 0 int my_f(unsigned n) @@ -961,9 +961,9 @@ f 8 10 12 8 18 #+END_SRC -It would seem that this is some sort of "least multiple of $b$ such that $b < a$ -given that $b$ is a power of two, but I feel as though I'm grasping at straws -here. +It would seem that this is some sort of "least multiple of \(b\) such that \(b < +a\) given that \(b\) is a power of two, but I feel as though I'm grasping at +straws here. As a Gentoo user, I have the Linux source tree checked out at =/usr/src/linux=, and because the hint mentions low-level programming, I decided to create a @@ -1222,9 +1222,9 @@ realization that =helper= worked with hexadecimal digits got me started on ideas for what =f= might do. On the topic of =helper=, the reason I was able to pick out that it's checking for -hexadecimal digits was realizing that $a - 48 \leq 9$ is equivalent to $a \leq -49 + 9$. The comparison is otherwise pretty unclear. And I suspect that the =-33= -is related to how ASCII is encoded. +hexadecimal digits was realizing that \(a - 48 \leq 9\) is equivalent to \(a +\leq 49 + 9\). The comparison is otherwise pretty unclear. And I suspect that +the =-33= is related to how ASCII is encoded. The control flow for =f= is pretty intimidating with its 8 labels. When it came time to look at =f=, I drew out a rudimentary control flow graph on paper -- @@ -1234,25 +1234,5 @@ the graph), which are conditionals (branches), and which labels are related (linear relationships). #+BEGIN_EXPORT html -<script type="text/x-mathjax-config"> -MathJax.Hub.Config({ - displayAlign: "center", - displayIndent: "0em", - - "HTML-CSS": { scale: 100, - linebreaks: { automatic: "false" }, - webFont: "TeX" - }, - SVG: {scale: 100, - linebreaks: { automatic: "false" }, - font: "TeX"}, - NativeMML: {scale: 100}, - TeX: { equationNumbers: {autoNumber: "AMS"}, - MultLineWidth: "85%", - TagSide: "right", - TagIndent: ".8em" - } -}); -</script> -<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS_HTML"></script> +<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/latest.js?config=TeX-MML-AM_CHTML"></script> #+END_EXPORT |