[PATCH] x86/bugs: Correct RSB terminology in Kconfig

From: Breno Leitao
Date: Fri Sep 13 2024 - 08:28:12 EST


RSB stands for "Return Stack Buffer" in industry literature[1]. Update
the kernel Kconfig to use this standard term instead of the current
"Return-Speculation-Buffer".

This change aligns kernel documentation with widely accepted terminology.

The line length reduction triggers text reformatting, but no functional
text is altered.

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/return-stack-buffer-underflow.html

Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
arch/x86/Kconfig | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 007bab9f2a0e..5d87d5d7c6d0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2554,15 +2554,14 @@ config MITIGATION_CALL_DEPTH_TRACKING
default y
help
Compile the kernel with call depth tracking to mitigate the Intel
- SKL Return-Speculation-Buffer (RSB) underflow issue. The
- mitigation is off by default and needs to be enabled on the
- kernel command line via the retbleed=stuff option. For
- non-affected systems the overhead of this option is marginal as
- the call depth tracking is using run-time generated call thunks
- in a compiler generated padding area and call patching. This
- increases text size by ~5%. For non affected systems this space
- is unused. On affected SKL systems this results in a significant
- performance gain over the IBRS mitigation.
+ SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off
+ by default and needs to be enabled on the kernel command line via the
+ retbleed=stuff option. For non-affected systems the overhead of this
+ option is marginal as the call depth tracking is using run-time
+ generated call thunks in a compiler generated padding area and call
+ patching. This increases text size by ~5%. For non affected systems
+ this space is unused. On affected SKL systems this results in a
+ significant performance gain over the IBRS mitigation.

config CALL_THUNKS_DEBUG
bool "Enable call thunks and call depth tracking debugging"
--
2.43.5