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 --- include/video/display_timing.h | 105 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 include/video/display_timing.h (limited to 'include/video/display_timing.h') diff --git a/include/video/display_timing.h b/include/video/display_timing.h new file mode 100644 index 000000000..37a017607 --- /dev/null +++ b/include/video/display_timing.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2012 Steffen Trumtrar + * + * description of display timings + */ + +#ifndef __LINUX_DISPLAY_TIMING_H +#define __LINUX_DISPLAY_TIMING_H + +#include +#include + +enum display_flags { + DISPLAY_FLAGS_HSYNC_LOW = BIT(0), + DISPLAY_FLAGS_HSYNC_HIGH = BIT(1), + DISPLAY_FLAGS_VSYNC_LOW = BIT(2), + DISPLAY_FLAGS_VSYNC_HIGH = BIT(3), + + /* data enable flag */ + DISPLAY_FLAGS_DE_LOW = BIT(4), + DISPLAY_FLAGS_DE_HIGH = BIT(5), + /* drive data on pos. edge */ + DISPLAY_FLAGS_PIXDATA_POSEDGE = BIT(6), + /* drive data on neg. edge */ + DISPLAY_FLAGS_PIXDATA_NEGEDGE = BIT(7), + DISPLAY_FLAGS_INTERLACED = BIT(8), + DISPLAY_FLAGS_DOUBLESCAN = BIT(9), + DISPLAY_FLAGS_DOUBLECLK = BIT(10), + /* drive sync on pos. edge */ + DISPLAY_FLAGS_SYNC_POSEDGE = BIT(11), + /* drive sync on neg. edge */ + DISPLAY_FLAGS_SYNC_NEGEDGE = BIT(12), +}; + +/* + * A single signal can be specified via a range of minimal and maximal values + * with a typical value, that lies somewhere inbetween. + */ +struct timing_entry { + u32 min; + u32 typ; + u32 max; +}; + +/* + * Single "mode" entry. This describes one set of signal timings a display can + * have in one setting. This struct can later be converted to struct videomode + * (see include/video/videomode.h). As each timing_entry can be defined as a + * range, one struct display_timing may become multiple struct videomodes. + * + * Example: hsync active high, vsync active low + * + * Active Video + * Video ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________ + * |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync.. + * | | porch | | porch | + * + * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯ + * + * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________ + */ +struct display_timing { + struct timing_entry pixelclock; + + struct timing_entry hactive; /* hor. active video */ + struct timing_entry hfront_porch; /* hor. front porch */ + struct timing_entry hback_porch; /* hor. back porch */ + struct timing_entry hsync_len; /* hor. sync len */ + + struct timing_entry vactive; /* ver. active video */ + struct timing_entry vfront_porch; /* ver. front porch */ + struct timing_entry vback_porch; /* ver. back porch */ + struct timing_entry vsync_len; /* ver. sync len */ + + enum display_flags flags; /* display flags */ +}; + +/* + * This describes all timing settings a display provides. + * The native_mode is the default setting for this display. + * Drivers that can handle multiple videomodes should work with this struct and + * convert each entry to the desired end result. + */ +struct display_timings { + unsigned int num_timings; + unsigned int native_mode; + + struct display_timing **timings; +}; + +/* get one entry from struct display_timings */ +static inline struct display_timing *display_timings_get(const struct + display_timings *disp, + unsigned int index) +{ + if (disp->num_timings > index) + return disp->timings[index]; + else + return NULL; +} + +void display_timings_release(struct display_timings *disp); + +#endif -- cgit v1.3.1