Commit f5c0b4f3 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov
Browse files

x86/prctl: Remove pointless task argument 



The functions invoked via do_arch_prctl_common() can only operate on
the current task and none of these function uses the task argument.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/87lev7vtxj.ffs@tglx
parent 1ff2fb98

arch/x86/include/asm/fpu/api.h

+1 −2
Original line number Diff line number Diff line
@@ -162,7 +162,6 @@ static inline bool fpstate_is_confidential(struct fpu_guest *gfpu) 
}



/* prctl */

struct task_struct;

extern long fpu_xstate_prctl(struct task_struct *tsk, int option, unsigned long arg2);

extern long fpu_xstate_prctl(int option, unsigned long arg2);



#endif /* _ASM_X86_FPU_API_H */

arch/x86/include/asm/proto.h

+1 −2
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ void x86_report_nx(void); 


extern int reboot_force;



long do_arch_prctl_common(struct task_struct *task, int option,

			  unsigned long arg2);

long do_arch_prctl_common(int option, unsigned long arg2);



#endif /* _ASM_X86_PROTO_H */

arch/x86/kernel/fpu/xstate.c

+1 −4
Original line number Diff line number Diff line
@@ -1687,16 +1687,13 @@ EXPORT_SYMBOL_GPL(xstate_get_guest_group_perm); 
 * e.g. for AMX which requires XFEATURE_XTILE_CFG(17) and

 * XFEATURE_XTILE_DATA(18) this would be XFEATURE_XTILE_DATA(18).

 */

long fpu_xstate_prctl(struct task_struct *tsk, int option, unsigned long arg2)

long fpu_xstate_prctl(int option, unsigned long arg2)

{

	u64 __user *uptr = (u64 __user *)arg2;

	u64 permitted, supported;

	unsigned long idx = arg2;

	bool guest = false;



	if (tsk != current)

		return -EPERM;



	switch (option) {

	case ARCH_GET_XCOMP_SUPP:

		supported = fpu_user_cfg.max_features |	fpu_user_cfg.legacy_features;

arch/x86/kernel/process.c

+4 −5
Original line number Diff line number Diff line
@@ -334,7 +334,7 @@ static int get_cpuid_mode(void) 
	return !test_thread_flag(TIF_NOCPUID);

}



static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled)

static int set_cpuid_mode(unsigned long cpuid_enabled)

{

	if (!boot_cpu_has(X86_FEATURE_CPUID_FAULT))

		return -ENODEV;
@@ -985,20 +985,19 @@ unsigned long __get_wchan(struct task_struct *p) 
	return addr;

}



long do_arch_prctl_common(struct task_struct *task, int option,

			  unsigned long arg2)

long do_arch_prctl_common(int option, unsigned long arg2)

{

	switch (option) {

	case ARCH_GET_CPUID:

		return get_cpuid_mode();

	case ARCH_SET_CPUID:

		return set_cpuid_mode(task, arg2);

		return set_cpuid_mode(arg2);

	case ARCH_GET_XCOMP_SUPP:

	case ARCH_GET_XCOMP_PERM:

	case ARCH_REQ_XCOMP_PERM:

	case ARCH_GET_XCOMP_GUEST_PERM:

	case ARCH_REQ_XCOMP_GUEST_PERM:

		return fpu_xstate_prctl(task, option, arg2);

		return fpu_xstate_prctl(option, arg2);

	}



	return -EINVAL;

arch/x86/kernel/process_32.c

+1 −1
Original line number Diff line number Diff line
@@ -222,5 +222,5 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) 


SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)

{

	return do_arch_prctl_common(current, option, arg2);

	return do_arch_prctl_common(option, arg2);

}