Merge tag 'riscv-for-linus-v7.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linuxHEADmaster

Pull RISC-V updates from Paul Walmsley:
 "Before v7.0 is released, fix a few issues with the CFI patchset,
  merged earlier in v7.0-rc, that primarily affect interfaces to
  non-kernel code:

   - Improve the prctl() interface for per-task indirect branch landing
     pad control to expand abbreviations and to resemble the speculation
     control prctl() interface

   - Expand the "LP" and "SS" abbreviations in the ptrace uapi header
     file to "branch landing pad" and "shadow stack", to improve
     readability

   - Fix a typo in a CFI-related macro name in the ptrace uapi header
     file

   - Ensure that the indirect branch tracking state and shadow stack
     state are unlocked immediately after an exec() on the new task so
     that libc subsequently can control it

   - While working in this area, clean up the kernel-internal,
     cross-architecture prctl() function names by expanding the
     abbreviations mentioned above"

* tag 'riscv-for-linus-v7.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  prctl: cfi: change the branch landing pad prctl()s to be more descriptive
  riscv: ptrace: cfi: expand "SS" references to "shadow stack" in uapi headers
  prctl: rename branch landing pad implementation functions to be more explicit
  riscv: ptrace: expand "LP" references to "branch landing pads" in uapi headers
  riscv: cfi: clear CFI lock status in start_thread()
  riscv: ptrace: cfi: fix "PRACE" typo in uapi header

1 files changed, 17 insertions, 13 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index c86eba9aa7e9..62e842055cc9 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -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;
 }
@@ -2888,20 +2889,23 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 			return -EINVAL;
 		error = rseq_slice_extension_prctl(arg2, arg3);
 		break;
-	case PR_GET_INDIR_BR_LP_STATUS:
-		if (arg3 || arg4 || arg5)
+	case PR_GET_CFI:
+		if (arg2 != PR_CFI_BRANCH_LANDING_PADS)
 			return -EINVAL;
-		error = arch_get_indir_br_lp_status(me, (unsigned long __user *)arg2);
-		break;
-	case PR_SET_INDIR_BR_LP_STATUS:
-		if (arg3 || arg4 || arg5)
+		if (arg4 || arg5)
 			return -EINVAL;
-		error = arch_set_indir_br_lp_status(me, arg2);
+		error = arch_prctl_get_branch_landing_pad_state(me, (unsigned long __user *)arg3);
 		break;
-	case PR_LOCK_INDIR_BR_LP_STATUS:
-		if (arg3 || arg4 || arg5)
+	case PR_SET_CFI:
+		if (arg2 != PR_CFI_BRANCH_LANDING_PADS)
 			return -EINVAL;
-		error = arch_lock_indir_br_lp_status(me, arg2);
+		if (arg4 || arg5)
+			return -EINVAL;
+		error = arch_prctl_set_branch_landing_pad_state(me, arg3);
+		if (error)
+			break;
+		if (arg3 & PR_CFI_LOCK && !(arg3 & PR_CFI_DISABLE))
+			error = arch_prctl_lock_branch_landing_pad_state(me);
 		break;
 	default:
 		trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5);