[PATCH v2 4/6] x86/cpu: Remove "nosmep"

Borislav Petkov
2022-01-27T11:56:48Z

From: Borislav Petkov <bp@suse.de>

There should be no need to disable SMEP anymore.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
---
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 04b155a4298f..e3894159c22b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3398,7 +3398,7 @@
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 12fbe2b1e98a..08246e8ac835 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 7e5d695279bc..3d0a5340a678 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -291,13 +291,6 @@ 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))
--
2.29.2