Kernel slides: update CONFIG_STRICT_DEVMEM explanations

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
bootlin · Apr 23, 2021 · d66f6bc · d66f6bc
1 parent 6c26779
commit d66f6bc
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/slides/kernel-driver-development-io-memory/kernel-driver-development-io-memory.tex b/slides/kernel-driver-development-io-memory/kernel-driver-development-io-memory.tex
@@ -266,9 +266,11 @@ \section{I/O Memory and Ports}
     address.
   \item Used by applications such as the X server to write directly to
     device memory.
-  \item On \code{x86}, \code{arm}, \code{arm64},
-    \code{powerpc}, \code{s390}:
+  \item On \code{x86}, \code{arm}, \code{arm64}, \code{riscv},
+    \code{powerpc}, \code{parisc}, \code{s390}:
     \kconfig{CONFIG_STRICT_DEVMEM} option to restrict \code{/dev/mem}
-    to non-RAM addresses, for security reasons (Linux 4.20 status).
+    to non-RAM addresses, for security reasons (Linux 5.12 status).
+    \kconfig{CONFIG_IO_STRICT_DEVMEM} goes beyond and only allows to access
+    {\em idle} I/O ranges (not appearing in \code{/proc/iomem}).
 \end{itemize}
 \end{frame}