Re: [PATCH v7 15/28] powerpc/kprobes: Use patch_instruction()
From: Alistair Popple <hidden>
Date: 2020-05-05 01:43:11
Without CONFIG_STRICT_KERNEL_RWX this boils down to doing the same thing (although with a few more safety checks along the way), and with CONFIG_STRICT_KERNEL_RWX this should make it actually work (although perhaps there was some other mechanism that made it work anyway). Reviewed-by: Alistair Popple <redacted> On Friday, 1 May 2020 1:42:07 PM AEST Jordan Niethe wrote:
quoted hunk ↗ jump to hunk
Instead of using memcpy() and flush_icache_range() use patch_instruction() which not only accomplishes both of these steps but will also make it easier to add support for prefixed instructions. Signed-off-by: Jordan Niethe <redacted> --- v6: New to series. --- arch/powerpc/kernel/kprobes.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index f64312dca84f..a72c8e1a42ad 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c@@ -125,11 +125,8 @@ int arch_prepare_kprobe(struct kprobe *p) } if (!ret) { - memcpy(p->ainsn.insn, p->addr, - MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); + patch_instruction((struct ppc_inst *)p->ainsn.insn, insn); p->opcode = ppc_inst_val(insn); - flush_icache_range((unsigned long)p->ainsn.insn, - (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t)); } p->ainsn.boostable = 0;