Commit adfc80dd authored by Paul Walmsley's avatar Paul Walmsley
Browse files

prctl: rename branch landing pad implementation functions to be more explicit 

Per Linus' comments about the unreadability of abbreviations such as
"indir_br_lp", rename the three prctl() implementation functions to be more
explicit.  This involves renaming "indir_br_lp_status" in the function
names to "branch_landing_pad_state".

While here, add _prctl_ into the function names, following the
speculation control prctl implementation functions.

Link: https://lore.kernel.org/linux-riscv/CAHk-=whhSLGZAx3N5jJpb4GLFDqH_QvS07D+6BnkPWmCEzTAgw@mail.gmail.com/


Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: default avatarPaul Walmsley <pjw@kernel.org>
parent ac4e61c7

arch/riscv/kernel/usercfi.c

+8 −8
Original line number Diff line number Diff line
@@ -457,7 +457,8 @@ int arch_lock_shadow_stack_status(struct task_struct *task, 
	return 0;

}



int arch_get_indir_br_lp_status(struct task_struct *t, unsigned long __user *status)

int arch_prctl_get_branch_landing_pad_state(struct task_struct *t,

					    unsigned long __user *state)

{

	unsigned long fcfi_status = 0;
@@ -467,10 +468,10 @@ int arch_get_indir_br_lp_status(struct task_struct *t, unsigned long __user *sta 
	/* indirect branch tracking is enabled on the task or not */

	fcfi_status |= (is_indir_lp_enabled(t) ? PR_INDIR_BR_LP_ENABLE : 0);



	return copy_to_user(status, &fcfi_status, sizeof(fcfi_status)) ? -EFAULT : 0;

	return copy_to_user(state, &fcfi_status, sizeof(fcfi_status)) ? -EFAULT : 0;

}



int arch_set_indir_br_lp_status(struct task_struct *t, unsigned long status)

int arch_prctl_set_branch_landing_pad_state(struct task_struct *t, unsigned long state)

{

	bool enable_indir_lp = false;
@@ -482,24 +483,23 @@ int arch_set_indir_br_lp_status(struct task_struct *t, unsigned long status) 
		return -EINVAL;



	/* Reject unknown flags */

	if (status & ~PR_INDIR_BR_LP_ENABLE)

	if (state & ~PR_INDIR_BR_LP_ENABLE)

		return -EINVAL;



	enable_indir_lp = (status & PR_INDIR_BR_LP_ENABLE);

	enable_indir_lp = (state & PR_INDIR_BR_LP_ENABLE);

	set_indir_lp_status(t, enable_indir_lp);



	return 0;

}



int arch_lock_indir_br_lp_status(struct task_struct *task,

				 unsigned long arg)

int arch_prctl_lock_branch_landing_pad_state(struct task_struct *task)

{

	/*

	 * If indirect branch tracking is not supported or not enabled on task,

	 * nothing to lock here

	 */

	if (!is_user_lpad_enabled() ||

	    !is_indir_lp_enabled(task) || arg != 0)

	    !is_indir_lp_enabled(task))

		return -EINVAL;



	set_indir_lp_lock(task, true);

include/linux/cpu.h

+3 −3
Original line number Diff line number Diff line
@@ -229,8 +229,8 @@ static inline bool cpu_attack_vector_mitigated(enum cpu_attack_vectors v) 
#define smt_mitigations SMT_MITIGATIONS_OFF

#endif



int arch_get_indir_br_lp_status(struct task_struct *t, unsigned long __user *status);

int arch_set_indir_br_lp_status(struct task_struct *t, unsigned long status);

int arch_lock_indir_br_lp_status(struct task_struct *t, unsigned long status);

int arch_prctl_get_branch_landing_pad_state(struct task_struct *t, unsigned long __user *state);

int arch_prctl_set_branch_landing_pad_state(struct task_struct *t, unsigned long state);

int arch_prctl_lock_branch_landing_pad_state(struct task_struct *t);



#endif /* _LINUX_CPU_H_ */

kernel/sys.c

+8 −7
Original line number Diff line number Diff line
@@ -2388,17 +2388,18 @@ int __weak arch_lock_shadow_stack_status(struct task_struct *t, unsigned long st 
	return -EINVAL;

}



int __weak arch_get_indir_br_lp_status(struct task_struct *t, unsigned long __user *status)

int __weak arch_prctl_get_branch_landing_pad_state(struct task_struct *t,

						   unsigned long __user *state)

{

	return -EINVAL;

}



int __weak arch_set_indir_br_lp_status(struct task_struct *t, unsigned long status)

int __weak arch_prctl_set_branch_landing_pad_state(struct task_struct *t, unsigned long state)

{

	return -EINVAL;

}



int __weak arch_lock_indir_br_lp_status(struct task_struct *t, unsigned long status)

int __weak arch_prctl_lock_branch_landing_pad_state(struct task_struct *t)

{

	return -EINVAL;

}
@@ -2891,17 +2892,17 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 
	case PR_GET_INDIR_BR_LP_STATUS:

		if (arg3 || arg4 || arg5)

			return -EINVAL;

		error = arch_get_indir_br_lp_status(me, (unsigned long __user *)arg2);

		error = arch_prctl_get_branch_landing_pad_state(me, (unsigned long __user *)arg2);

		break;

	case PR_SET_INDIR_BR_LP_STATUS:

		if (arg3 || arg4 || arg5)

			return -EINVAL;

		error = arch_set_indir_br_lp_status(me, arg2);

		error = arch_prctl_set_branch_landing_pad_state(me, arg2);

		break;

	case PR_LOCK_INDIR_BR_LP_STATUS:

		if (arg3 || arg4 || arg5)

		if (arg2 || arg3 || arg4 || arg5)

			return -EINVAL;

		error = arch_lock_indir_br_lp_status(me, arg2);

		error = arch_prctl_lock_branch_landing_pad_state(me);

		break;

	default:

		trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5);