The following commit has been merged into the x86/cpu branch of tip:
Commit-ID: 385d2ae0a1b5efacb30e13a0f0e521490441d9bb
Gitweb: https://git.kernel.org/tip/385d2ae0a1b5efacb30e13a0f0e521490441d9bb
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Thu, 27 Jan 2022 12:56:24 +01:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Mon, 04 Apr 2022 10:17:00 +02:00
x86/cpu: Remove "nosmep"
There should be no need to disable SMEP anymore.
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220127115626.14179-5-bp@xxxxxxxxx
---
Documentation/admin-guide/kernel-parameters.txt | 2 +-
Documentation/x86/cpuinfo.rst | 4 ++--
arch/x86/kernel/cpu/common.c | 7 -------
3 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e0bb710..39ac2c1 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3465,7 +3465,7 @@
Disable SMAP (Supervisor Mode Access Prevention)
even if it is supported by processor.
- nosmep [X86,PPC64s]
+ nosmep [PPC64s]
Disable SMEP (Supervisor Mode Execution Prevention)
even if it is supported by processor.
diff --git a/Documentation/x86/cpuinfo.rst b/Documentation/x86/cpuinfo.rst
index 12fbe2b..08246e8 100644
--- a/Documentation/x86/cpuinfo.rst
+++ b/Documentation/x86/cpuinfo.rst
@@ -140,8 +140,8 @@ from #define X86_FEATURE_UMIP (16*32 + 2).
In addition, there exists a variety of custom command-line parameters that
disable specific features. The list of parameters includes, but is not limited
-to, nofsgsbase, and nosmep. 5-level paging can also be disabled using
-"no5lvl". SMEP is disabled with the aforementioned parameter.
+to, nofsgsbase, nosgx, noxsave, etc. 5-level paging can also be disabled using
+"no5lvl".
e: The feature was known to be non-functional.
----------------------------------------------
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 747df07..5791f69 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -369,13 +369,6 @@ static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
}
#endif
-static __init int setup_disable_smep(char *arg)
-{
- setup_clear_cpu_cap(X86_FEATURE_SMEP);
- return 1;
-}
-__setup("nosmep", setup_disable_smep);
-
static __always_inline void setup_smep(struct cpuinfo_x86 *c)
{
if (cpu_has(c, X86_FEATURE_SMEP))
|