selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
new file mode 100644
index 000000000..8ca1a0a22
--- /dev/null
+++ b/drivers/tty/Makefile
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_TTY)		+= tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o \
+				   tty_buffer.o tty_port.o tty_mutex.o \
+				   tty_ldsem.o tty_baudrate.o tty_jobctrl.o \
+				   n_null.o
+obj-$(CONFIG_LEGACY_PTYS)	+= pty.o
+obj-$(CONFIG_UNIX98_PTYS)	+= pty.o
+obj-$(CONFIG_AUDIT)		+= tty_audit.o
+obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o
+obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
+obj-$(CONFIG_N_GSM)		+= n_gsm.o
+
+obj-y				+= vt/
+obj-$(CONFIG_HVC_DRIVER)	+= hvc/
+obj-y				+= serial/
+obj-$(CONFIG_SERIAL_DEV_BUS)	+= serdev/
+
+# tty drivers
+obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
+obj-$(CONFIG_MOXA_INTELLIO)	+= moxa.o
+obj-$(CONFIG_MOXA_SMARTIO)	+= mxser.o
+obj-$(CONFIG_NOZOMI)		+= nozomi.o
+obj-$(CONFIG_NULL_TTY)	        += ttynull.o
+obj-$(CONFIG_PPC_EPAPR_HV_BYTECHAN) += ehv_bytechan.o
+obj-$(CONFIG_GOLDFISH_TTY)	+= goldfish.o
+obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o
+obj-$(CONFIG_VCC)		+= vcc.o
+obj-$(CONFIG_RPMSG_TTY)		+= rpmsg_tty.o
+
+obj-y += ipwireless/