Commit 5f1dd4dd authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/fsgsbase: Replace static_cpu_has() with boot_cpu_has() 



ptrace and prctl() are not really fast paths to warrant the use of
static_cpu_has() and cause alternatives patching for no good reason.
Replace with boot_cpu_has() which is simple and fast enough.

No functional changes.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200818103715.32736-1-bp@alien8.de
parent 0b2c605f

arch/x86/include/asm/fsgsbase.h

+2 −2
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static inline unsigned long x86_fsbase_read_cpu(void) 
{

	unsigned long fsbase;



	if (static_cpu_has(X86_FEATURE_FSGSBASE))

	if (boot_cpu_has(X86_FEATURE_FSGSBASE))

		fsbase = rdfsbase();

	else

		rdmsrl(MSR_FS_BASE, fsbase);
@@ -67,7 +67,7 @@ static inline unsigned long x86_fsbase_read_cpu(void) 


static inline void x86_fsbase_write_cpu(unsigned long fsbase)

{

	if (static_cpu_has(X86_FEATURE_FSGSBASE))

	if (boot_cpu_has(X86_FEATURE_FSGSBASE))

		wrfsbase(fsbase);

	else

		wrmsrl(MSR_FS_BASE, fsbase);

arch/x86/kernel/process_64.c

+4 −4
Original line number Diff line number Diff line
@@ -407,7 +407,7 @@ unsigned long x86_gsbase_read_cpu_inactive(void) 
{

	unsigned long gsbase;



	if (static_cpu_has(X86_FEATURE_FSGSBASE)) {

	if (boot_cpu_has(X86_FEATURE_FSGSBASE)) {

		unsigned long flags;



		local_irq_save(flags);
@@ -422,7 +422,7 @@ unsigned long x86_gsbase_read_cpu_inactive(void) 


void x86_gsbase_write_cpu_inactive(unsigned long gsbase)

{

	if (static_cpu_has(X86_FEATURE_FSGSBASE)) {

	if (boot_cpu_has(X86_FEATURE_FSGSBASE)) {

		unsigned long flags;



		local_irq_save(flags);
@@ -439,7 +439,7 @@ unsigned long x86_fsbase_read_task(struct task_struct *task) 


	if (task == current)

		fsbase = x86_fsbase_read_cpu();

	else if (static_cpu_has(X86_FEATURE_FSGSBASE) ||

	else if (boot_cpu_has(X86_FEATURE_FSGSBASE) ||

		 (task->thread.fsindex == 0))

		fsbase = task->thread.fsbase;

	else
@@ -454,7 +454,7 @@ unsigned long x86_gsbase_read_task(struct task_struct *task) 


	if (task == current)

		gsbase = x86_gsbase_read_cpu_inactive();

	else if (static_cpu_has(X86_FEATURE_FSGSBASE) ||

	else if (boot_cpu_has(X86_FEATURE_FSGSBASE) ||

		 (task->thread.gsindex == 0))

		gsbase = task->thread.gsbase;

	else

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