On Tue, Dec 03, 2024 at 08:44:50PM +0100, Christophe Leroy wrote:
> Add support for 'bla' instruction.
>
> This is done by 'flagging' the address as an absolute address so that
> arch_jump_destination() can calculate it as expected. Because code is
> _always_ 4 bytes aligned, use bit 30 as flag.
The AA field already is there, so why not, eh :-)
> Also add support for 'b' and 'ba' instructions. Objtool call them jumps.
> Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
Reviewed-by: Segher Boessenkool <seg...@kewrnel.crashing.org>
> --- a/tools/objtool/arch/powerpc/decode.c
> +++ b/tools/objtool/arch/powerpc/decode.c
> @@ -55,12 +55,15 @@ int arch_decode_instruction(struct objtool_file *file,
> const struct section *sec
>
> switch (opcode) {
> case 18: /* b[l][a] */
> - if ((ins & 3) == 1) /* bl */
> + if (ins & 1) /* bl[a] */
> typ = INSN_CALL;
> + else /* b[a] */
> + typ = INSN_JUMP_UNCONDITIONAL;
>
> imm = ins & 0x3fffffc;
> if (imm & 0x2000000)
> imm -= 0x4000000;
> + imm |= ins & 2; /* AA flag */
You could of course put that together with the 3fffffc thing, but you
can leave that to the compiler as well :-)
Segher
