Merge tag 'x86-urgent-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A small set of x86 fixes:

   - Cure IO bitmap inconsistencies

     A failed fork cleans up all resources of the newly created thread
     via exit_thread(). exit_thread() invokes io_bitmap_exit() which
     does the IO bitmap cleanups, which unfortunately assume that the
     cleanup is related to the current task, which is obviously bogus.

     Make it work correctly

   - A lockdep fix in the resctrl code removed the clearing of the
     command buffer in two places, which keeps stale error messages
     around. Bring them back.

   - Remove unused trace events"

* tag 'x86-urgent-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  fs/resctrl: Restore the rdt_last_cmd_clear() calls after acquiring rdtgroup_mutex
  x86/iopl: Cure TIF_IO_BITMAP inconsistencies
  x86/fpu: Remove unused trace events

3 files changed, 15 insertions, 19 deletions

diff --git a/arch/x86/include/asm/trace/fpu.h b/arch/x86/include/asm/trace/fpu.h
index 0454d5e60e5d..721b408d9a67 100644
--- a/arch/x86/include/asm/trace/fpu.h
+++ b/arch/x86/include/asm/trace/fpu.h
@@ -44,16 +44,6 @@ DEFINE_EVENT(x86_fpu, x86_fpu_after_save,
 	TP_ARGS(fpu)
 );
 
-DEFINE_EVENT(x86_fpu, x86_fpu_before_restore,
-	TP_PROTO(struct fpu *fpu),
-	TP_ARGS(fpu)
-);
-
-DEFINE_EVENT(x86_fpu, x86_fpu_after_restore,
-	TP_PROTO(struct fpu *fpu),
-	TP_ARGS(fpu)
-);
-
 DEFINE_EVENT(x86_fpu, x86_fpu_regs_activated,
 	TP_PROTO(struct fpu *fpu),
 	TP_ARGS(fpu)
@@ -64,11 +54,6 @@ DEFINE_EVENT(x86_fpu, x86_fpu_regs_deactivated,
 	TP_ARGS(fpu)
 );
 
-DEFINE_EVENT(x86_fpu, x86_fpu_init_state,
-	TP_PROTO(struct fpu *fpu),
-	TP_ARGS(fpu)
-);
-
 DEFINE_EVENT(x86_fpu, x86_fpu_dropped,
 	TP_PROTO(struct fpu *fpu),
 	TP_ARGS(fpu)
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 6290dd120f5e..ff40f09ad911 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -33,8 +33,9 @@ void io_bitmap_share(struct task_struct *tsk)
 	set_tsk_thread_flag(tsk, TIF_IO_BITMAP);
 }
 
-static void task_update_io_bitmap(struct task_struct *tsk)
+static void task_update_io_bitmap(void)
 {
+	struct task_struct *tsk = current;
 	struct thread_struct *t = &tsk->thread;
 
 	if (t->iopl_emul == 3 || t->io_bitmap) {
@@ -54,7 +55,12 @@ void io_bitmap_exit(struct task_struct *tsk)
 	struct io_bitmap *iobm = tsk->thread.io_bitmap;
 
 	tsk->thread.io_bitmap = NULL;
-	task_update_io_bitmap(tsk);
+	/*
+	 * Don't touch the TSS when invoked on a failed fork(). TSS
+	 * reflects the state of @current and not the state of @tsk.
+	 */
+	if (tsk == current)
+		task_update_io_bitmap();
 	if (iobm && refcount_dec_and_test(&iobm->refcnt))
 		kfree(iobm);
 }
@@ -192,8 +198,7 @@ SYSCALL_DEFINE1(iopl, unsigned int, level)
 	}
 
 	t->iopl_emul = level;
-	task_update_io_bitmap(current);
-
+	task_update_io_bitmap();
 	return 0;
 }
 
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c1d2dac72b9c..704883c21f3a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -176,6 +176,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	frame->ret_addr = (unsigned long) ret_from_fork_asm;
 	p->thread.sp = (unsigned long) fork_frame;
 	p->thread.io_bitmap = NULL;
+	clear_tsk_thread_flag(p, TIF_IO_BITMAP);
 	p->thread.iopl_warn = 0;
 	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
 
@@ -464,6 +465,11 @@ void native_tss_update_io_bitmap(void)
 	} else {
 		struct io_bitmap *iobm = t->io_bitmap;
 
+		if (WARN_ON_ONCE(!iobm)) {
+			clear_thread_flag(TIF_IO_BITMAP);
+			native_tss_invalidate_io_bitmap();
+		}
+
 		/*
 		 * Only copy bitmap data when the sequence number differs. The
 		 * update time is accounted to the incoming task.