github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-31 10:33:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

x86/bugs: Add a separate config for Spectre v1

Browse Source 
Currently, the CONFIG_SPECULATION_MITIGATIONS is halfway populated,
where some mitigations have entries in Kconfig, and they could be
modified, while others mitigations do not have Kconfig entries, and
could not be controlled at build time.

Create an entry for the Spectre v1 CPU mitigation under
CONFIG_SPECULATION_MITIGATIONS. This allow users to enable or disable
it at compilation time.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20240729164105.554296-7-leitao@debian.org
This commit is contained in:
Breno Leitao 2024-07-29 09:40:54 -07:00 committed by Borislav Petkov (AMD)
parent 894e28857c
commit ca01c0d8d0
2 changed files with 12 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/x86/Kconfig
View File

@ -2705,6 +2705,16 @@ config MITIGATION_RETBLEED
unprivileged attacker can use these flaws to bypass conventional
memory security restrictions to gain read access to privileged memory
that would otherwise be inaccessible.
config MITIGATION_SPECTRE_V1
bool "Mitigate SPECTRE V1 hardware bug"
default y
help
Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a
class of side channel attacks that takes advantage of speculative
execution that bypasses conditional branch instructions used for
memory access bounds check.
See also <file:Documentation/admin-guide/hw-vuln/spectre.rst>
endif
config ARCH_HAS_ADD_PAGES

3
arch/x86/kernel/cpu/bugs.c
View File

@ -874,7 +874,8 @@ enum spectre_v1_mitigation {
};
static enum spectre_v1_mitigation spectre_v1_mitigation __ro_after_init =
SPECTRE_V1_MITIGATION_AUTO;
IS_ENABLED(CONFIG_MITIGATION_SPECTRE_V1) ?
SPECTRE_V1_MITIGATION_AUTO : SPECTRE_V1_MITIGATION_NONE;
static const char * const spectre_v1_strings[] = {
[SPECTRE_V1_MITIGATION_NONE] = "Vulnerable: __user pointer sanitization and usercopy barriers only; no swapgs barriers",