Commit 99436f7d authored Nov 17, 2014 by Maciej W. Rozycki Committed by Ralf Baechle Nov 19, 2014

MIPS: jump_label.c: Correct the span of the J instruction



Correct the check for the span of the 256MB segment addressable by the J
instruction according to this instruction's semantics.  The calculation
of the jump target is applied to the address of the delay-slot
instruction that immediately follows.  Adjust the check accordingly by
adding 4 to `e->code' that holds the address of the J instruction
itself.

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8515/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent 640465bd

arch/mips/kernel/jump_label.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -27,8 +27,8 @@ void arch_jump_label_transform(struct jump_entry *e,
		union mips_instruction *insn_p =
		(union mips_instruction *)(unsigned long)e->code;

		/* Jump only works within a 256MB aligned region. */
		BUG_ON((e->target & ~J_RANGE_MASK) != (e->code & ~J_RANGE_MASK));
		/* Jump only works within a 256MB aligned region of its delay slot. */
		BUG_ON((e->target & ~J_RANGE_MASK) != ((e->code + 4) & ~J_RANGE_MASK));

		/* Target must have 4 byte alignment. */
		BUG_ON((e->target & 3) != 0);