From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- arch/mips/mm/sc-debugfs.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 arch/mips/mm/sc-debugfs.c (limited to 'arch/mips/mm/sc-debugfs.c') diff --git a/arch/mips/mm/sc-debugfs.c b/arch/mips/mm/sc-debugfs.c new file mode 100644 index 000000000..80ff39471 --- /dev/null +++ b/arch/mips/mm/sc-debugfs.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2015 Imagination Technologies + * Author: Paul Burton + */ + +#include +#include +#include +#include +#include + +static ssize_t sc_prefetch_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + bool enabled = bc_prefetch_is_enabled(); + char buf[3]; + + buf[0] = enabled ? 'Y' : 'N'; + buf[1] = '\n'; + buf[2] = 0; + + return simple_read_from_buffer(user_buf, count, ppos, buf, 2); +} + +static ssize_t sc_prefetch_write(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + bool enabled; + int err; + + err = kstrtobool_from_user(user_buf, count, &enabled); + if (err) + return err; + + if (enabled) + bc_prefetch_enable(); + else + bc_prefetch_disable(); + + return count; +} + +static const struct file_operations sc_prefetch_fops = { + .open = simple_open, + .llseek = default_llseek, + .read = sc_prefetch_read, + .write = sc_prefetch_write, +}; + +static int __init sc_debugfs_init(void) +{ + struct dentry *dir; + + dir = debugfs_create_dir("l2cache", mips_debugfs_dir); + debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir, NULL, + &sc_prefetch_fops); + return 0; +} +late_initcall(sc_debugfs_init); -- cgit v1.3.1