Commit 622cf6f4 authored by Jordan Niethe's avatar Jordan Niethe Committed by Michael Ellerman
Browse files

powerpc: Introduce a function for reporting instruction length 



Currently all instructions have the same length, but in preparation for
prefixed instructions introduce a function for returning instruction
length.

Signed-off-by: default avatarJordan Niethe <jniethe5@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarAlistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-18-jniethe5@gmail.com
parent 5249385a

arch/powerpc/include/asm/inst.h

+5 −0
Original line number Diff line number Diff line
@@ -17,6 +17,11 @@ static inline u32 ppc_inst_val(struct ppc_inst x) 
	return x.val;

}



static inline int ppc_inst_len(struct ppc_inst x)

{

	return sizeof(struct ppc_inst);

}



static inline int ppc_inst_primary_opcode(struct ppc_inst x)

{

	return ppc_inst_val(x) >> 26;

arch/powerpc/kernel/kprobes.c

+4 −2
Original line number Diff line number Diff line
@@ -462,14 +462,16 @@ NOKPROBE_SYMBOL(trampoline_probe_handler); 
 */

int kprobe_post_handler(struct pt_regs *regs)

{

	int len;

	struct kprobe *cur = kprobe_running();

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();



	if (!cur || user_mode(regs))

		return 0;



	len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn));

	/* make sure we got here for instruction we have a kprobe on */

	if (((unsigned long)cur->ainsn.insn + 4) != regs->nip)

	if (((unsigned long)cur->ainsn.insn + len) != regs->nip)

		return 0;



	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
@@ -478,7 +480,7 @@ int kprobe_post_handler(struct pt_regs *regs) 
	}



	/* Adjust nip to after the single-stepped instruction */

	regs->nip = (unsigned long)cur->addr + 4;

	regs->nip = (unsigned long)cur->addr + len;

	regs->msr |= kcb->kprobe_saved_msr;



	/*Restore back the original saved kprobes variables and continue. */

arch/powerpc/kernel/uprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -112,7 +112,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) 
	 * support doesn't exist and have to fix-up the next instruction

	 * to be executed.

	 */

	regs->nip = utask->vaddr + MAX_UINSN_BYTES;

	regs->nip = utask->vaddr + ppc_inst_len(ppc_inst_read(&auprobe->insn));



	user_disable_single_step(current);

	return 0;

arch/powerpc/lib/feature-fixups.c

+7 −7
Original line number Diff line number Diff line
@@ -392,20 +392,20 @@ void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end) 
static void do_final_fixups(void)

{

#if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)

	struct ppc_inst *src, *dest;

	unsigned long length;

	struct ppc_inst inst, *src, *dest, *end;



	if (PHYSICAL_START == 0)

		return;



	src = (struct ppc_inst *)(KERNELBASE + PHYSICAL_START);

	dest = (struct ppc_inst *)KERNELBASE;

	length = (__end_interrupts - _stext) / sizeof(struct ppc_inst);

	end = (void *)src + (__end_interrupts - _stext);



	while (length--) {

		raw_patch_instruction(dest, ppc_inst_read(src));

		src++;

		dest++;

	while (src < end) {

		inst = ppc_inst_read(src);

		raw_patch_instruction(dest, inst);

		src = (void *)src + ppc_inst_len(inst);

		dest = (void *)dest + ppc_inst_len(inst);

	}

#endif

}