Hi Stafford,
On Tue, 5 Aug 2025 at 11:15, Stafford Horne <[email protected]> wrote:
> On Tue, Aug 05, 2025 at 08:40:57AM +0000, ChenMiao wrote:
> > From: chenmiao <[email protected]>
> >
> > We need a text patching mechanism to ensure that in the subsequent
> > implementation of jump_label, the code can be modified to the correct
> > location. Therefore, FIX_TEXT_POKE0 has been added as a mapping area.
> >
> > And, I create a new file named insn-def.h to define the or1k insn macro
> > size and more define in the future.
> >
> > Among these changes, we implement patch_map and support the
> > patch_insn_write API for single instruction writing.
> >
> > Signed-off-by: chenmiao <[email protected]>
> > --- /dev/null
> > +++ b/arch/openrisc/include/asm/insn-def.h
> > +/* or1k instructions are always 32 bits. */
> > +#define OPENRISC_INSN_SIZE 4
> > --- /dev/null
> > +++ b/arch/openrisc/kernel/patching.c
> > +static int __patch_insn_write(void *addr, const void *insn)
> > +{
> > + void *waddr = addr;
> > + unsigned long flags = 0;
> > + int ret;
> > +
> > + raw_spin_lock_irqsave(&patch_lock, flags);
> > +
> > + waddr = patch_map(addr, FIX_TEXT_POKE0);
> > +
> > + ret = copy_to_kernel_nofault(waddr, insn, OPENRISC_INSN_SIZE);
>
> If you change *insn to unsigned long insn, you can do:
>
> ret = copy_to_kernel_nofault(waddr, &insn, iszeof(insn));
sizeof(*insn)?
>
> > + local_icache_range_inv((unsigned long)waddr,
> > + (unsigned long)waddr + OPENRISC_INSN_SIZE);
> > +
> > + patch_unmap(FIX_TEXT_POKE0);
> > +
> > + raw_spin_unlock_irqrestore(&patch_lock, flags);
> > +
> > + return ret;
> > +}
> > +
> > +int patch_insn_write(void *addr, const void *insn)
>
> Does insn need to be void *? It think it could be just unsigned long. See
> comment above.
u32?
unsigned long would be 64-bit on 64-bit platforms.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
