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powerpc: Introduce a function for reporting instruction length

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

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-18-jniethe5@gmail.com
This commit is contained in:
Jordan Niethe 2020-05-06 13:40:37 +10:00 committed by Michael Ellerman
parent 5249385ad7
commit 622cf6f436
4 changed files with 17 additions and 10 deletions
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5
arch/powerpc/include/asm/inst.h
View File

@ -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;

6
arch/powerpc/kernel/kprobes.c
View File

@ -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. */

2
arch/powerpc/kernel/uprobes.c
View File

@ -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;

14
arch/powerpc/lib/feature-fixups.c
View File

@ -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
}