diff --git a/llvm/docs/CommandGuide/llvm-readelf.rst b/llvm/docs/CommandGuide/llvm-readelf.rst
--- a/llvm/docs/CommandGuide/llvm-readelf.rst
+++ b/llvm/docs/CommandGuide/llvm-readelf.rst
@@ -163,7 +163,8 @@
 .. option:: --stack-sizes
 
  Display the contents of the stack sizes section(s), i.e. pairs of function
- names and the size of their stack frames.
+ names and the size of their stack frames. Currently only implemented for GNU
+ style output.
 
 .. option:: --string-dump=<section[,section,...]>, -p
 
diff --git a/llvm/docs/CommandGuide/llvm-readobj.rst b/llvm/docs/CommandGuide/llvm-readobj.rst
--- a/llvm/docs/CommandGuide/llvm-readobj.rst
+++ b/llvm/docs/CommandGuide/llvm-readobj.rst
@@ -214,6 +214,12 @@
 
  Display the section to segment mapping.
 
+.. option:: --stack-sizes
+
+ Display the contents of the stack sizes section(s), i.e. pairs of function
+ names and the size of their stack frames. Currently only implemented for GNU
+ style output.
+
 .. option:: --version-info, -V
 
  Display version sections.