Patch "cpuidle, intel_idle: Fix CPUIDLE_FLAG_INIT_XSTATE" has been added to the 6.2-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cpuidle, intel_idle: Fix CPUIDLE_FLAG_INIT_XSTATE

to the 6.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cpuidle-intel_idle-fix-cpuidle_flag_init_xstate.patch
and it can be found in the queue-6.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0558144d79b9f95146517a0e61cc2787ed81509a
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date:   Thu Jan 12 20:43:33 2023 +0100

    cpuidle, intel_idle: Fix CPUIDLE_FLAG_INIT_XSTATE
    
    [ Upstream commit 821ad23d0eaff73ef599ece39ecc77482df20a8c ]
    
    Fix instrumentation bugs objtool found:
    
      vmlinux.o: warning: objtool: intel_idle_s2idle+0xd5: call to fpu_idle_fpregs() leaves .noinstr.text section
      vmlinux.o: warning: objtool: intel_idle_xstate+0x11: call to fpu_idle_fpregs() leaves .noinstr.text section
      vmlinux.o: warning: objtool: fpu_idle_fpregs+0x9: call to xfeatures_in_use() leaves .noinstr.text section
    
    Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
    Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
    Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
    Tested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
    Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
    Acked-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230112195540.494977795@xxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/x86/include/asm/fpu/xcr.h b/arch/x86/include/asm/fpu/xcr.h
index 9656a5bc6feae..9a710c0604457 100644
--- a/arch/x86/include/asm/fpu/xcr.h
+++ b/arch/x86/include/asm/fpu/xcr.h
@@ -5,7 +5,7 @@
 #define XCR_XFEATURE_ENABLED_MASK	0x00000000
 #define XCR_XFEATURE_IN_USE_MASK	0x00000001
 
-static inline u64 xgetbv(u32 index)
+static __always_inline u64 xgetbv(u32 index)
 {
 	u32 eax, edx;
 
@@ -27,7 +27,7 @@ static inline void xsetbv(u32 index, u64 value)
  *
  * Callers should check X86_FEATURE_XGETBV1.
  */
-static inline u64 xfeatures_in_use(void)
+static __always_inline u64 xfeatures_in_use(void)
 {
 	return xgetbv(XCR_XFEATURE_IN_USE_MASK);
 }
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 35f709f619fb4..c2e322189f853 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -295,7 +295,7 @@ static inline int enqcmds(void __iomem *dst, const void *src)
 	return 0;
 }
 
-static inline void tile_release(void)
+static __always_inline void tile_release(void)
 {
 	/*
 	 * Instruction opcode for TILERELEASE; supported in binutils
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 9baa89a8877d0..dccce58201b7c 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -853,12 +853,12 @@ int fpu__exception_code(struct fpu *fpu, int trap_nr)
  * Initialize register state that may prevent from entering low-power idle.
  * This function will be invoked from the cpuidle driver only when needed.
  */
-void fpu_idle_fpregs(void)
+noinstr void fpu_idle_fpregs(void)
 {
 	/* Note: AMX_TILE being enabled implies XGETBV1 support */
 	if (cpu_feature_enabled(X86_FEATURE_AMX_TILE) &&
 	    (xfeatures_in_use() & XFEATURE_MASK_XTILE)) {
 		tile_release();
-		fpregs_deactivate(&current->thread.fpu);
+		__this_cpu_write(fpu_fpregs_owner_ctx, NULL);
 	}
 }