From 16ef9767e4dc5cf03a71ae7bc2bc588dbbe7983e Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 26 May 2020 17:26:30 +1000 Subject: [PATCH] powerpc: Add ppc_inst_as_u64() The code patching code wants to get the value of a struct ppc_inst as a u64 when the instruction is prefixed, so we can pass the u64 down to __put_user_asm() and write it with a single store. The optprobes code wants to load a struct ppc_inst as an immediate into a register so it is useful to have it as a u64 to use the existing helper function. Currently this is a bit awkward because the value differs based on the CPU endianness, so add a helper to do the conversion. This fixes the usage in arch_prepare_optimized_kprobe() which was previously incorrect on big endian. Fixes: 650b55b707fd ("powerpc: Add prefixed instructions to instruction data type") Signed-off-by: Michael Ellerman Tested-by: Jordan Niethe Link: https://lore.kernel.org/r/20200526072630.2487363-1-mpe@ellerman.id.au --- arch/powerpc/include/asm/inst.h | 9 +++++++++ arch/powerpc/kernel/optprobes.c | 3 +-- arch/powerpc/lib/code-patching.c | 8 +------- 3 files changed, 11 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h index 5b756ba77ed2..45f3ec868258 100644 --- a/arch/powerpc/include/asm/inst.h +++ b/arch/powerpc/include/asm/inst.h @@ -113,6 +113,15 @@ static inline struct ppc_inst *ppc_inst_next(void *location, struct ppc_inst *va return location + ppc_inst_len(tmp); } +static inline u64 ppc_inst_as_u64(struct ppc_inst x) +{ +#ifdef CONFIG_CPU_LITTLE_ENDIAN + return (u64)ppc_inst_suffix(x) << 32 | ppc_inst_val(x); +#else + return (u64)ppc_inst_val(x) << 32 | ppc_inst_suffix(x); +#endif +} + int probe_user_read_inst(struct ppc_inst *inst, struct ppc_inst __user *nip); diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index 3ac105e7faae..69bfe96884e2 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -283,8 +283,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) * 3. load instruction to be emulated into relevant register, and */ temp = ppc_inst_read((struct ppc_inst *)p->ainsn.insn); - patch_imm64_load_insns(ppc_inst_val(temp) | ((u64)ppc_inst_suffix(temp) << 32), - 4, buff + TMPL_INSN_IDX); + patch_imm64_load_insns(ppc_inst_as_u64(temp), 4, buff + TMPL_INSN_IDX); /* * 4. branch back from trampoline diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 64cf621e5b00..5ecf0d635a8d 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -27,13 +27,7 @@ static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr if (!ppc_inst_prefixed(instr)) { __put_user_asm(ppc_inst_val(instr), patch_addr, err, "stw"); } else { -#ifdef CONFIG_CPU_LITTLE_ENDIAN - __put_user_asm((u64)ppc_inst_suffix(instr) << 32 | - ppc_inst_val(instr), patch_addr, err, "std"); -#else - __put_user_asm((u64)ppc_inst_val(instr) << 32 | - ppc_inst_suffix(instr), patch_addr, err, "std"); -#endif + __put_user_asm(ppc_inst_as_u64(instr), patch_addr, err, "std"); } if (err) -- 2.11.0