From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock 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 Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/video/fbdev/sbuslib.h | 63 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/video/fbdev/sbuslib.h (limited to 'drivers/video/fbdev/sbuslib.h') diff --git a/drivers/video/fbdev/sbuslib.h b/drivers/video/fbdev/sbuslib.h new file mode 100644 index 000000000..e9af2dc93 --- /dev/null +++ b/drivers/video/fbdev/sbuslib.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* sbuslib.h: SBUS fb helper library interfaces */ +#ifndef _SBUSLIB_H +#define _SBUSLIB_H + +struct device_node; +struct fb_info; +struct fb_var_screeninfo; +struct vm_area_struct; + +struct sbus_mmap_map { + unsigned long voff; + unsigned long poff; + unsigned long size; +}; + +#define SBUS_MMAP_FBSIZE(n) (-n) +#define SBUS_MMAP_EMPTY 0x80000000 + +extern void sbusfb_fill_var(struct fb_var_screeninfo *var, + struct device_node *dp, int bpp); +extern int sbusfb_mmap_helper(const struct sbus_mmap_map *map, + unsigned long physbase, unsigned long fbsize, + unsigned long iospace, + struct vm_area_struct *vma); +int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg, + struct fb_info *info, + int type, int fb_depth, unsigned long fb_size); +int sbusfb_compat_ioctl(struct fb_info *info, unsigned int cmd, + unsigned long arg); + +/* + * Initialize struct fb_ops for SBUS I/O. + */ + +#define __FB_DEFAULT_SBUS_OPS_RDWR(__prefix) \ + .fb_read = fb_io_read, \ + .fb_write = fb_io_write + +#define __FB_DEFAULT_SBUS_OPS_DRAW(__prefix) \ + .fb_fillrect = cfb_fillrect, \ + .fb_copyarea = cfb_copyarea, \ + .fb_imageblit = cfb_imageblit + +#ifdef CONFIG_COMPAT +#define __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix) \ + .fb_ioctl = __prefix ## _sbusfb_ioctl, \ + .fb_compat_ioctl = sbusfb_compat_ioctl +#else +#define __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix) \ + .fb_ioctl = __prefix ## _sbusfb_ioctl +#endif + +#define __FB_DEFAULT_SBUS_OPS_MMAP(__prefix) \ + .fb_mmap = __prefix ## _sbusfb_mmap + +#define FB_DEFAULT_SBUS_OPS(__prefix) \ + __FB_DEFAULT_SBUS_OPS_RDWR(__prefix), \ + __FB_DEFAULT_SBUS_OPS_DRAW(__prefix), \ + __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix), \ + __FB_DEFAULT_SBUS_OPS_MMAP(__prefix) + +#endif /* _SBUSLIB_H */ -- cgit v1.3.1