From 0566fa760d235c119cef92119efc3ab11486a08a Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Wed, 19 May 2021 16:17:18 +0530 Subject: [PATCH] powerpc/kprobes: Roll IS_RFI() macro into IS_RFID() In kprobes and xmon, we should exclude both 32-bit and 64-bit variants of mtmsr and rfi instructions from being stepped. Have IS_RFID() also detect a rfi instruction similar to IS_MTMSRD(). Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/eee32e1b75dae85d471c89b4c0a123ad4b0aabf8.1621416666.git.naveen.n.rao@linux.vnet.ibm.com --- arch/powerpc/include/asm/sstep.h | 7 +++---- arch/powerpc/kernel/kprobes.c | 4 ++-- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h index 972ed0df154d6..1df867c2e054e 100644 --- a/arch/powerpc/include/asm/sstep.h +++ b/arch/powerpc/include/asm/sstep.h @@ -13,12 +13,11 @@ struct pt_regs; * we don't allow putting a breakpoint on an mtmsrd instruction. * Similarly we don't allow breakpoints on rfid instructions. * These macros tell us if an instruction is a mtmsrd or rfid. - * Note that IS_MTMSRD returns true for both an mtmsr (32-bit) - * and an mtmsrd (64-bit). + * Note that these return true for both mtmsr/rfi (32-bit) + * and mtmsrd/rfid (64-bit). */ #define IS_MTMSRD(instr) ((ppc_inst_val(instr) & 0xfc0007be) == 0x7c000124) -#define IS_RFID(instr) ((ppc_inst_val(instr) & 0xfc0007fe) == 0x4c000024) -#define IS_RFI(instr) ((ppc_inst_val(instr) & 0xfc0007fe) == 0x4c000064) +#define IS_RFID(instr) ((ppc_inst_val(instr) & 0xfc0007be) == 0x4c000024) enum instruction_type { COMPUTE, /* arith/logical/CR op, etc. */ diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 04714895d3f90..2303511c77457 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -129,8 +129,8 @@ int arch_prepare_kprobe(struct kprobe *p) if ((unsigned long)p->addr & 0x03) { printk("Attempt to register kprobe at an unaligned address\n"); ret = -EINVAL; - } else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) { - printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n"); + } else if (IS_MTMSRD(insn) || IS_RFID(insn)) { + printk("Cannot register a kprobe on mtmsr[d]/rfi[d]\n"); ret = -EINVAL; } else if ((unsigned long)p->addr & ~PAGE_MASK && ppc_inst_prefixed(ppc_inst_read(p->addr - 1))) {