Revert "x86/alternative: Make custom return thunk unconditional"

This reverts commit 53ebbe1c8c02aa7b7f072dd2f96bca4faa1daa59.

Revert the backport of upstream commit:

  095b8303f383 ("x86/alternative: Make custom return thunk unconditional")

in order to backport the full version now that

  770ae1b70952 ("x86/returnthunk: Allow different return thunks")

has been backported.

Revert it here so that the build breakage is kept at minimum.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 04035edc5c758c255acc77dac9f3c9de8f1cfcfc..44c78af98af4bb1e4c2acf10a844828c2c1d2b83 100644 (file)
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -205,11 +205,7 @@
 typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
 extern retpoline_thunk_t __x86_indirect_thunk_array[];
 
-#ifdef CONFIG_RETHUNK
 extern void __x86_return_thunk(void);
-#else
-static inline void __x86_return_thunk(void) {}
-#endif
 
 extern void retbleed_return_thunk(void);
 extern void srso_return_thunk(void);

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 13dffc43ded020ce9e24c02ea8c8fed0eb2bcd3b..208e4938f35ba657ebe7e9f5e6d90cbff855e90d 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -62,8 +62,6 @@ EXPORT_SYMBOL_GPL(x86_pred_cmd);
 
 static DEFINE_MUTEX(spec_ctrl_mutex);
 
-void (*x86_return_thunk)(void) __ro_after_init = &__x86_return_thunk;
-
 /* Update SPEC_CTRL MSR and its cached copy unconditionally */
 static void update_spec_ctrl(u64 val)
 {