From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- drivers/video/fbdev/bt455.h | 90 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/video/fbdev/bt455.h (limited to 'drivers/video/fbdev/bt455.h') diff --git a/drivers/video/fbdev/bt455.h b/drivers/video/fbdev/bt455.h new file mode 100644 index 000000000..dd1404b40 --- /dev/null +++ b/drivers/video/fbdev/bt455.h @@ -0,0 +1,90 @@ +/* + * linux/drivers/video/bt455.h + * + * Copyright 2003 Thiemo Seufer + * Copyright 2016 Maciej W. Rozycki + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + */ +#include + +/* + * Bt455 byte-wide registers, 32-bit aligned. + */ +struct bt455_regs { + volatile u8 addr_cmap; + u8 pad0[3]; + volatile u8 addr_cmap_data; + u8 pad1[3]; + volatile u8 addr_clr; + u8 pad2[3]; + volatile u8 addr_ovly; + u8 pad3[3]; +}; + +static inline void bt455_select_reg(struct bt455_regs *regs, int ir) +{ + mb(); + regs->addr_cmap = ir & 0x0f; +} + +static inline void bt455_reset_reg(struct bt455_regs *regs) +{ + mb(); + regs->addr_clr = 0; +} + +/* + * Read/write to a Bt455 color map register. + */ +static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey) +{ + mb(); + regs->addr_cmap_data; + rmb(); + *grey = regs->addr_cmap_data & 0xf; + rmb(); + regs->addr_cmap_data; +} + +static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey) +{ + wmb(); + regs->addr_cmap_data = 0x0; + wmb(); + regs->addr_cmap_data = grey & 0xf; + wmb(); + regs->addr_cmap_data = 0x0; +} + +static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey) +{ + wmb(); + regs->addr_ovly = 0x0; + wmb(); + regs->addr_ovly = grey & 0xf; + wmb(); + regs->addr_ovly = 0x0; +} + +static inline void bt455_read_cmap_entry(struct bt455_regs *regs, + int cr, u8 *grey) +{ + bt455_select_reg(regs, cr); + bt455_read_cmap_next(regs, grey); +} + +static inline void bt455_write_cmap_entry(struct bt455_regs *regs, + int cr, u8 grey) +{ + bt455_select_reg(regs, cr); + bt455_write_cmap_next(regs, grey); +} + +static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey) +{ + bt455_reset_reg(regs); + bt455_write_ovly_next(regs, grey); +} -- cgit v1.3.1