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authorEduard Zingerman <eddyz87@gmail.com>2026-09-04 01:33:23 -0700
committerKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 12:58:04 +0200
commit836b2fe544a5e9b5ce116622cb36fba33838c6fd (patch)
tree95e38e4aaa0a6a78e373148b3d0af4aa2ab3d371 /drivers/video/fbdev/bt455.h
downloadlinux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.tar.gz
linux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.zip
selftests/bpf: Check that JMP32 pointer vs zero jumps are not predictedgrafted
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 <npc@anthropic.com> Suggested-by: Nicholas Carlini <npc@anthropic.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Diffstat (limited to 'drivers/video/fbdev/bt455.h')
-rw-r--r--drivers/video/fbdev/bt455.h90
1 files changed, 90 insertions, 0 deletions
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 <seufer@csv.ica.uni-stuttgart.de>
+ * Copyright 2016 Maciej W. Rozycki <macro@linux-mips.org>
+ *
+ * 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 <linux/types.h>
+
+/*
+ * 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);
+}