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| author | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-26 10:26:30 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-26 16:36:57 +0300 |
| commit | 16ef9767e4dc5cf03a71ae7bc2bc588dbbe7983e (patch) | |
| tree | 574eb06cfef4b030b39dd4494edd08c1f218b86d | |
| parent | c5ff46d69c410f7fac173e4fde3eea484b4b4eda (diff) | |
| download | linux-16ef9767e4dc5cf03a71ae7bc2bc588dbbe7983e.tar.xz | |
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 <mpe@ellerman.id.au>
Tested-by: Jordan Niethe <jniethe5@gmail.com>
Link: https://lore.kernel.org/r/20200526072630.2487363-1-mpe@ellerman.id.au
| -rw-r--r-- | arch/powerpc/include/asm/inst.h | 9 | ||||
| -rw-r--r-- | arch/powerpc/kernel/optprobes.c | 3 | ||||
| -rw-r--r-- | 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) |