From 650b55b707fdfa764e9f2b81314d3eb4216fb962 Mon Sep 17 00:00:00 2001
From: Jordan Niethe <jniethe5@gmail.com>
Date: Fri, 15 May 2020 12:12:55 +1000
Subject: [PATCH] powerpc: Add prefixed instructions to instruction data type
References: jsc#SLE-13847
Patch-mainline: v5.8-rc1
Git-commit: 650b55b707fdfa764e9f2b81314d3eb4216fb962
For powerpc64, redefine the ppc_inst type so both word and prefixed
instructions can be represented. On powerpc32 the type will remain the
same. Update places which had assumed instructions to be 4 bytes long.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
[mpe: Rework the get_user_inst() macros to be parameterised, and don't
assign to the dest if an error occurred. Use CONFIG_PPC64 not
__powerpc64__ in a few places. Address other comments from
Christophe. Fix some sparse complaints.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-24-jniethe5@gmail.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/include/asm/inst.h | 70 ++++++++++++++++++++++++---
arch/powerpc/include/asm/kprobes.h | 2 +-
arch/powerpc/include/asm/ppc-opcode.h | 3 ++
arch/powerpc/include/asm/uaccess.h | 36 ++++++++++++++
arch/powerpc/include/asm/uprobes.h | 2 +-
arch/powerpc/kernel/crash_dump.c | 2 +-
arch/powerpc/kernel/optprobes.c | 6 ++-
arch/powerpc/kernel/optprobes_head.S | 3 ++
arch/powerpc/lib/code-patching.c | 13 ++++-
arch/powerpc/lib/feature-fixups.c | 5 +-
arch/powerpc/lib/inst.c | 40 +++++++++++++++
arch/powerpc/lib/sstep.c | 4 +-
arch/powerpc/xmon/xmon.c | 4 +-
arch/powerpc/xmon/xmon_bpts.S | 2 +
14 files changed, 175 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index c7ea70e73073..d82e0c99cfa1 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -2,29 +2,80 @@
#ifndef _ASM_POWERPC_INST_H
#define _ASM_POWERPC_INST_H
+#include <asm/ppc-opcode.h>
+
/*
* Instruction data type for POWER
*/
struct ppc_inst {
u32 val;
+#ifdef CONFIG_PPC64
+ u32 suffix;
+#endif
} __packed;
-#define ppc_inst(x) ((struct ppc_inst){ .val = x })
-
static inline u32 ppc_inst_val(struct ppc_inst x)
{
return x.val;
}
-static inline int ppc_inst_len(struct ppc_inst x)
+static inline int ppc_inst_primary_opcode(struct ppc_inst x)
{
- return sizeof(struct ppc_inst);
+ return ppc_inst_val(x) >> 26;
}
-static inline int ppc_inst_primary_opcode(struct ppc_inst x)
+#ifdef CONFIG_PPC64
+#define ppc_inst(x) ((struct ppc_inst){ .val = (x), .suffix = 0xff })
+
+#define ppc_inst_prefix(x, y) ((struct ppc_inst){ .val = (x), .suffix = (y) })
+
+static inline u32 ppc_inst_suffix(struct ppc_inst x)
{
- return ppc_inst_val(x) >> 26;
+ return x.suffix;
+}
+
+static inline bool ppc_inst_prefixed(struct ppc_inst x)
+{
+ return (ppc_inst_primary_opcode(x) == 1) && ppc_inst_suffix(x) != 0xff;
+}
+
+static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
+{
+ return ppc_inst_prefix(swab32(ppc_inst_val(x)),
+ swab32(ppc_inst_suffix(x)));
+}
+
+static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr)
+{
+ u32 val, suffix;
+
+ val = *(u32 *)ptr;
+ if ((val >> 26) == OP_PREFIX) {
+ suffix = *((u32 *)ptr + 1);
+ return ppc_inst_prefix(val, suffix);
+ } else {
+ return ppc_inst(val);
+ }
+}
+
+static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)
+{
+ return *(u64 *)&x == *(u64 *)&y;
+}
+
+#else
+
+#define ppc_inst(x) ((struct ppc_inst){ .val = x })
+
+static inline bool ppc_inst_prefixed(struct ppc_inst x)
+{
+ return false;
+}
+
+static inline u32 ppc_inst_suffix(struct ppc_inst x)
+{
+ return 0;
}
static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
@@ -42,6 +93,13 @@ static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)
return ppc_inst_val(x) == ppc_inst_val(y);
}
+#endif /* CONFIG_PPC64 */
+
+static inline int ppc_inst_len(struct ppc_inst x)
+{
+ return ppc_inst_prefixed(x) ? 8 : 4;
+}
+
int probe_user_read_inst(struct ppc_inst *inst,
struct ppc_inst __user *nip);
diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h
index 66b3f2983b22..4fc0e15e23a5 100644
--- a/arch/powerpc/include/asm/kprobes.h
+++ b/arch/powerpc/include/asm/kprobes.h
@@ -43,7 +43,7 @@ extern kprobe_opcode_t optprobe_template_ret[];
extern kprobe_opcode_t optprobe_template_end[];
/* Fixed instruction size for powerpc */
-#define MAX_INSN_SIZE 1
+#define MAX_INSN_SIZE 2
#define MAX_OPTIMIZED_LENGTH sizeof(kprobe_opcode_t) /* 4 bytes */
#define MAX_OPTINSN_SIZE (optprobe_template_end - optprobe_template_entry)
#define RELATIVEJUMP_SIZE sizeof(kprobe_opcode_t) /* 4 bytes */
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index c1df75edde44..2a39c716c343 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -158,6 +158,9 @@
/* VMX Vector Store Instructions */
#define OP_31_XOP_STVX 231
+/* Prefixed Instructions */
+#define OP_PREFIX 1
+
#define OP_31 31
#define OP_LWZ 32
#define OP_STFS 52
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 0d2d0c3dc527..c0523efa1458 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -105,6 +105,40 @@ static inline int __access_ok(unsigned long addr, unsigned long size,
#define __put_user_inatomic(x, ptr) \
__put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+#ifdef CONFIG_PPC64
+
+#define ___get_user_instr(gu_op, dest, ptr) \
+({ \
+ long __gui_ret = 0; \
+ unsigned long __gui_ptr = (unsigned long)ptr; \
+ struct ppc_inst __gui_inst; \
+ unsigned int __prefix, __suffix; \
+ __gui_ret = gu_op(__prefix, (unsigned int __user *)__gui_ptr); \
+ if (__gui_ret == 0) { \
+ if ((__prefix >> 26) == OP_PREFIX) { \
+ __gui_ret = gu_op(__suffix, \
+ (unsigned int __user *)__gui_ptr + 1); \
+ __gui_inst = ppc_inst_prefix(__prefix, \
+ __suffix); \
+ } else { \
+ __gui_inst = ppc_inst(__prefix); \
+ } \
+ if (__gui_ret == 0) \
+ (dest) = __gui_inst; \
+ } \
+ __gui_ret; \
+})
+
+#define get_user_instr(x, ptr) \
+ ___get_user_instr(get_user, x, ptr)
+
+#define __get_user_instr(x, ptr) \
+ ___get_user_instr(__get_user, x, ptr)
+
+#define __get_user_instr_inatomic(x, ptr) \
+ ___get_user_instr(__get_user_inatomic, x, ptr)
+
+#else /* !CONFIG_PPC64 */
#define get_user_instr(x, ptr) \
get_user((x).val, (u32 __user *)(ptr))
@@ -114,6 +148,8 @@ static inline int __access_ok(unsigned long addr, unsigned long size,
#define __get_user_instr_inatomic(x, ptr) \
__get_user_nosleep((x).val, (u32 __user *)(ptr), sizeof(u32))
+#endif /* CONFIG_PPC64 */
+
extern long __put_user_bad(void);
/*
diff --git a/arch/powerpc/include/asm/uprobes.h b/arch/powerpc/include/asm/uprobes.h
index 7e3b329ba2d3..5bf65f5d44a9 100644
--- a/arch/powerpc/include/asm/uprobes.h
+++ b/arch/powerpc/include/asm/uprobes.h
@@ -15,7 +15,7 @@
typedef ppc_opcode_t uprobe_opcode_t;
-#define MAX_UINSN_BYTES 4
+#define MAX_UINSN_BYTES 8
#define UPROBE_XOL_SLOT_BYTES (MAX_UINSN_BYTES)
/* The following alias is needed for reference from arch-agnostic code */
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index 72bafb47e757..735e89337398 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -46,7 +46,7 @@ static void __init create_trampoline(unsigned long addr)
* two instructions it doesn't require any registers.
*/
patch_instruction(p, ppc_inst(PPC_INST_NOP));
- patch_branch(++p, addr + PHYSICAL_START, 0);
+ patch_branch((void *)p + 4, addr + PHYSICAL_START, 0);
}
void __init setup_kdump_trampoline(void)
diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c
index 8eea8dbb93fa..3ac105e7faae 100644
--- a/arch/powerpc/kernel/optprobes.c
+++ b/arch/powerpc/kernel/optprobes.c
@@ -198,7 +198,7 @@ void patch_imm64_load_insns(unsigned long val, int reg, kprobe_opcode_t *addr)
int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
{
- struct ppc_inst branch_op_callback, branch_emulate_step;
+ struct ppc_inst branch_op_callback, branch_emulate_step, temp;
kprobe_opcode_t *op_callback_addr, *emulate_step_addr, *buff;
long b_offset;
unsigned long nip, size;
@@ -282,7 +282,9 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
/*
* 3. load instruction to be emulated into relevant register, and
*/
- patch_imm32_load_insns(*p->ainsn.insn, buff + TMPL_INSN_IDX);
+ 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);
/*
* 4. branch back from trampoline
diff --git a/arch/powerpc/kernel/optprobes_head.S b/arch/powerpc/kernel/optprobes_head.S
index cf383520843f..ff8ba4d3824d 100644
--- a/arch/powerpc/kernel/optprobes_head.S
+++ b/arch/powerpc/kernel/optprobes_head.S
@@ -94,6 +94,9 @@ optprobe_template_insn:
/* 2, Pass instruction to be emulated in r4 */
nop
nop
+ nop
+ nop
+ nop
.global optprobe_template_call_emulate
optprobe_template_call_emulate:
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index d946f7d6bb32..e9a0ea1c7ba4 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -24,7 +24,18 @@ static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr
{
int err = 0;
- __put_user_asm(ppc_inst_val(instr), patch_addr, err, "stw");
+ 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
+ }
+
if (err)
return err;
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 0c9ffdef8096..1fb845f60f43 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -84,12 +84,13 @@ static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
src = alt_start;
dest = start;
- for (; src < alt_end; src++, dest++) {
+ for (; src < alt_end; src = (void *)src + ppc_inst_len(ppc_inst_read(src)),
+ (dest = (void *)dest + ppc_inst_len(ppc_inst_read(dest)))) {
if (patch_alt_instruction(src, dest, alt_start, alt_end))
return 1;
}
- for (; dest < end; dest++)
+ for (; dest < end; dest = (void *)dest + ppc_inst_len(ppc_inst(PPC_INST_NOP)))
raw_patch_instruction(dest, ppc_inst(PPC_INST_NOP));
return 0;
diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c
index bf3126ee399d..aedfd6e31e53 100644
--- a/arch/powerpc/lib/inst.c
+++ b/arch/powerpc/lib/inst.c
@@ -4,8 +4,47 @@
*/
#include <linux/uaccess.h>
+#include <asm/disassemble.h>
#include <asm/inst.h>
+#include <asm/ppc-opcode.h>
+#ifdef CONFIG_PPC64
+int probe_user_read_inst(struct ppc_inst *inst,
+ struct ppc_inst __user *nip)
+{
+ unsigned int val, suffix;
+ int err;
+
+ err = probe_user_read(&val, nip, sizeof(val));
+ if (err)
+ return err;
+ if (get_op(val) == OP_PREFIX) {
+ err = probe_user_read(&suffix, (void __user *)nip + 4, 4);
+ *inst = ppc_inst_prefix(val, suffix);
+ } else {
+ *inst = ppc_inst(val);
+ }
+ return err;
+}
+
+int probe_kernel_read_inst(struct ppc_inst *inst,
+ struct ppc_inst *src)
+{
+ unsigned int val, suffix;
+ int err;
+
+ err = probe_kernel_read(&val, src, sizeof(val));
+ if (err)
+ return err;
+ if (get_op(val) == OP_PREFIX) {
+ err = probe_kernel_read(&suffix, (void *)src + 4, 4);
+ *inst = ppc_inst_prefix(val, suffix);
+ } else {
+ *inst = ppc_inst(val);
+ }
+ return err;
+}
+#else /* !CONFIG_PPC64 */
int probe_user_read_inst(struct ppc_inst *inst,
struct ppc_inst __user *nip)
{
@@ -31,3 +70,4 @@ int probe_kernel_read_inst(struct ppc_inst *inst,
return err;
}
+#endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 95a56bb1ba3f..ecd756c346fd 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1169,10 +1169,12 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
unsigned long int imm;
unsigned long int val, val2;
unsigned int mb, me, sh;
- unsigned int word;
+ unsigned int word, suffix;
long ival;
word = ppc_inst_val(instr);
+ suffix = ppc_inst_suffix(instr);
+
op->type = COMPUTE;
opcode = ppc_inst_primary_opcode(instr);
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 00b24f357c2b..ac8ccf333d51 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -758,8 +758,8 @@ static int xmon_bpt(struct pt_regs *regs)
/* Are we at the trap at bp->instr[1] for some bp? */
bp = in_breakpoint_table(regs->nip, &offset);
- if (bp != NULL && offset == 4) {
- regs->nip = bp->address + 4;
+ if (bp != NULL && (offset == 4 || offset == 8)) {
+ regs->nip = bp->address + offset;
atomic_dec(&bp->ref_count);
return 1;
}
diff --git a/arch/powerpc/xmon/xmon_bpts.S b/arch/powerpc/xmon/xmon_bpts.S
index f3ad0ab50854..69726814cd27 100644
--- a/arch/powerpc/xmon/xmon_bpts.S
+++ b/arch/powerpc/xmon/xmon_bpts.S
@@ -4,6 +4,8 @@
#include <asm/asm-offsets.h>
#include "xmon_bpts.h"
+/* Prefixed instructions can not cross 64 byte boundaries */
+.align 6
.global bpt_table
bpt_table:
.space NBPTS * BPT_SIZE
--
2.26.2