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powerpc: Use a datatype for instructions

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Currently unsigned ints are used to represent instructions on powerpc.
This has worked well as instructions have always been 4 byte words.

However, ISA v3.1 introduces some changes to instructions that mean
this scheme will no longer work as well. This change is Prefixed
Instructions. A prefixed instruction is made up of a word prefix
followed by a word suffix to make an 8 byte double word instruction.
No matter the endianness of the system the prefix always comes first.
Prefixed instructions are only planned for powerpc64.

Introduce a ppc_inst type to represent both prefixed and word
instructions on powerpc64 while keeping it possible to exclusively
have word instructions on powerpc32.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Fix compile error in emulate_spe()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
This commit is contained in:
Jordan Niethe
2020-05-06 13:40:31 +10:00
committed by Michael Ellerman
parent 217862d9b9
commit 94afd069d9
26 changed files with 237 additions and 214 deletions
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8
arch/powerpc/kernel/kprobes.c
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@@ -106,7 +106,7 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
kprobe_opcode_t insn = *p->addr;
struct ppc_inst insn = *(struct ppc_inst *)p->addr;
if ((unsigned long)p->addr & 0x03) {
printk("Attempt to register kprobe at an unaligned address\n");
@@ -139,13 +139,13 @@ NOKPROBE_SYMBOL(arch_prepare_kprobe);
void arch_arm_kprobe(struct kprobe *p)
{
patch_instruction(p->addr, ppc_inst(BREAKPOINT_INSTRUCTION));
patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION));
}
NOKPROBE_SYMBOL(arch_arm_kprobe);
void arch_disarm_kprobe(struct kprobe *p)
{
patch_instruction(p->addr, ppc_inst(p->opcode));
patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode));
}
NOKPROBE_SYMBOL(arch_disarm_kprobe);
@@ -217,7 +217,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
{
int ret;
unsigned int insn = *p->ainsn.insn;
struct ppc_inst insn = *(struct ppc_inst *)p->ainsn.insn;
/* regs->nip is also adjusted if emulate_step returns 1 */
ret = emulate_step(regs, insn);