On Wed, 2020-04-15 at 14:40 +1000, Jordan Niethe wrote:
> On Mon, Apr 13, 2020 at 10:04 PM Balamuruhan S <bal...@linux.ibm.com> wrote:
> > On Mon, 2020-04-06 at 18:09 +1000, Jordan Niethe wrote:
> > > 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 <jniet...@gmail.com>
> > > ---
> > > v4: New to series
> > > v5: - Distinguish normal instructions from prefixed instructions with a
> > > 0xff marker for the suffix.
> > > - __patch_instruction() using std for prefixed instructions
> > > ---
> > > arch/powerpc/include/asm/inst.h | 71 ++++++++++++++++++++++++++--
> > > arch/powerpc/include/asm/kprobes.h | 2 +-
> > > arch/powerpc/include/asm/uaccess.h | 31 ++++++++++--
> > > arch/powerpc/include/asm/uprobes.h | 2 +-
> > > arch/powerpc/kernel/optprobes.c | 42 ++++++++--------
> > > arch/powerpc/kernel/optprobes_head.S | 3 ++
> > > arch/powerpc/kernel/trace/ftrace.c | 26 +++++++++-
> > > arch/powerpc/lib/code-patching.c | 19 +++++---
> > > arch/powerpc/lib/feature-fixups.c | 5 +-
> > > arch/powerpc/lib/sstep.c | 4 +-
> > > arch/powerpc/xmon/xmon.c | 6 +--
> > > arch/powerpc/xmon/xmon_bpts.S | 4 +-
> > > 12 files changed, 171 insertions(+), 44 deletions(-)
> > >
> > > diff --git a/arch/powerpc/include/asm/inst.h
> > > b/arch/powerpc/include/asm/inst.h
> > > index 70b37a35a91a..7e23e7146c66 100644
> > > --- a/arch/powerpc/include/asm/inst.h
> > > +++ b/arch/powerpc/include/asm/inst.h
> > > @@ -8,23 +8,67 @@
> > >
> > > struct ppc_inst {
> > > u32 val;
> > > +#ifdef __powerpc64__
> > > + u32 suffix;
> > > +#endif /* __powerpc64__ */
> > > } __packed;
> > >
> > > -#define ppc_inst(x) ((struct ppc_inst){ .val = x })
> > > +static inline int ppc_inst_opcode(struct ppc_inst x)
> > > +{
> > > + return x.val >> 26;
> >
> > why don't we wrap here and in `ppc_inst_opcode()` in patch 9 using
> > `ppc_inst_val()` ?
> Will do.
> >
> > > +}
> > >
> > > static inline u32 ppc_inst_val(struct ppc_inst x)
> >
> > There is another same definition below for the same function in
> > #else part of __powerpc64__ ifdef.
> Thanks
> >
> > > {
> > > return x.val;
> > > }
> > >
> > > -static inline bool ppc_inst_len(struct ppc_inst x)
> > > +#ifdef __powerpc64__
> > > +#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 sizeof(struct ppc_inst);
> > > + return x.suffix;
> > > }
> > >
> > > -static inline int ppc_inst_opcode(struct ppc_inst x)
> > > +static inline bool ppc_inst_prefixed(struct ppc_inst x) {
> > > + return ((ppc_inst_val(x) >> 26) == 1) && ppc_inst_suffix(x) !=
> > > 0xff;
> > > +}
> > > +
> > > +static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
> > > {
> > > - return x.val >> 26;
> > > + 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 = 0xff;
> > > + val = *(u32 *)ptr;
> > > + if ((val >> 26) == 1)
> > > + suffix = *((u32 *)ptr + 1);
> > > + return ppc_inst_prefix(val, suffix);
> > > +}
> > > +
> > > +static inline void ppc_inst_write(struct ppc_inst *ptr, struct ppc_inst
> > > x)
> > > +{
> > > + if (ppc_inst_prefixed(x)) {
> > > + *(u32 *)ptr = x.val;
> > > + *((u32 *)ptr + 1) = x.suffix;
> > > + } else {
> > > + *(u32 *)ptr = x.val;
> >
> > can we wrap here as well with `ppc_inst_val()` and `ppc_inst_suffix()` ?
> Yeah no reason not too.
> >
> > > + }
> > > +}
> > > +
> > > +#else
> > > +
> > > +#define ppc_inst(x) ((struct ppc_inst){ .val = x })
> > > +
> > > +static inline bool ppc_inst_prefixed(ppc_inst x)
> > > +{
> > > + return 0;
> >
> > Is it return !!0 or return false ?
> False probably will make more sense.
> >
> > > }
> > >
> > > static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
> > > @@ -32,14 +76,31 @@ static inline struct ppc_inst ppc_inst_swab(struct
> > > ppc_inst x)
> > > return ppc_inst(swab32(ppc_inst_val(x)));
> > > }
> > >
> > > +static inline u32 ppc_inst_val(struct ppc_inst x)
> >
> > [...] duplicate definition that is defined outside __powerpc64__ above.
> >
> >
> > > +{
> > > + return x.val;
> > > +}
> > > +
> > > static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr)
> > > {
> > > return *ptr;
> > > }
> > >
> > > +static inline void ppc_inst_write(struct ppc_inst *ptr, struct ppc_inst
> > > x)
> > > +{
> > > + *ptr = x;
> > > +}
> > > +
> > > +#endif /* __powerpc64__ */
> > > +
> > > static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)
> > > {
> > > return !memcmp(&x, &y, sizeof(struct ppc_inst));
> > > }
> > >
> > > +static inline int ppc_inst_len(struct ppc_inst x)
> > > +{
> > > + return (ppc_inst_prefixed(x)) ? 8 : 4;
> > > +}
> > > +
> > > #endif /* _ASM_INST_H */
> > > 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/uaccess.h
> > > b/arch/powerpc/include/asm/uaccess.h
> > > index c0a35e4586a5..5a3f486ddf02 100644
> > > --- a/arch/powerpc/include/asm/uaccess.h
> > > +++ b/arch/powerpc/include/asm/uaccess.h
> > > @@ -105,11 +105,34 @@ 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)))
> > >
> > > -#define __get_user_instr(x, ptr) \
> > > - __get_user_nocheck((x).val, (u32 *)(ptr), sizeof(u32), true)
> > > +#define __get_user_instr(x, ptr) \
> > > +({ \
> > > + long __gui_ret = 0; \
> > > + unsigned int prefix, suffix; \
> > > + __gui_ret = __get_user(prefix, (unsigned int __user *)ptr);
> > > \
> > > + if (!__gui_ret && (prefix >> 26) == 1) { \
> > > + __gui_ret = __get_user(suffix, (unsigned int __user *)ptr +
> > > 1);
> > > \
> > > + (x) = ppc_inst_prefix(prefix, suffix); \
> > > + } else { \
> > > + (x) = ppc_inst(prefix); \
> > > + } \
> > > + __gui_ret; \
> > > +})
> > > +
> > > +#define __get_user_instr_inatomic(x, ptr) \
> > > +({ \
> > > + long __gui_ret = 0; \
> > > + unsigned int prefix, suffix; \
> > > + __gui_ret = __get_user_inatomic(prefix, (unsigned int __user
> > > *)ptr);
> > > \
> > > + if (!__gui_ret && (prefix >> 26) == 1) { \
> > > + __gui_ret = __get_user_inatomic(suffix, (unsigned int
> > > __user
> > > *)ptr + 1); \
> > > + (x) = ppc_inst_prefix(prefix, suffix); \
> > > + } else { \
> > > + (x) = ppc_inst(prefix); \
> > > + } \
> > > + __gui_ret; \
> > > +})
> > >
> > > -#define __get_user_instr_inatomic(x, ptr) \
> > > - __get_user_nosleep((x).val, (u32 *)(ptr), sizeof(u32))
> > > 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/optprobes.c
> > > b/arch/powerpc/kernel/optprobes.c
> > > index 684640b8fa2e..689daf430161 100644
> > > --- a/arch/powerpc/kernel/optprobes.c
> > > +++ b/arch/powerpc/kernel/optprobes.c
> > > @@ -159,38 +159,38 @@ void patch_imm32_load_insns(unsigned int val,
> > > kprobe_opcode_t *addr)
> > >
> > > /*
> > > * Generate instructions to load provided immediate 64-bit value
> > > - * to register 'r3' and patch these instructions at 'addr'.
> > > + * to register 'reg' and patch these instructions at 'addr'.
> > > */
> > > -void patch_imm64_load_insns(unsigned long val, kprobe_opcode_t *addr)
> > > +void patch_imm64_load_insns(unsigned long val, int reg, kprobe_opcode_t
> > > *addr)
> > > {
> > > - /* lis r3,(op)@highest */
> > > - patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ADDIS
> > > |
> > > ___PPC_RT(3) |
> > > + /* lis reg,(op)@highest */
> > > + patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ADDIS
> > > |
> > > ___PPC_RT(reg) |
> > > ((val >> 48) & 0xffff)));
> > > addr++;
> > >
> > > - /* ori r3,r3,(op)@higher */
> > > - patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ORI |
> > > ___PPC_RA(3) |
> > > - ___PPC_RS(3) | ((val >> 32) & 0xffff)));
> > > + /* ori reg,reg,(op)@higher */
> > > + patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ORI |
> > > ___PPC_RA(reg) |
> > > + ___PPC_RS(reg) | ((val >> 32) & 0xffff)));
> > > addr++;
> > >
> > > - /* rldicr r3,r3,32,31 */
> > > - patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_RLDICR
> > > |
> > > ___PPC_RA(3) |
> > > - ___PPC_RS(3) | __PPC_SH64(32) | __PPC_ME64(31)));
> > > + /* rldicr reg,reg,32,31 */
> > > + patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_RLDICR
> > > |
> > > ___PPC_RA(reg) |
> > > + ___PPC_RS(reg) | __PPC_SH64(32) |
> > > __PPC_ME64(31)));
> > > addr++;
> > >
> > > - /* oris r3,r3,(op)@h */
> > > - patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ORIS |
> > > ___PPC_RA(3) |
> > > - ___PPC_RS(3) | ((val >> 16) & 0xffff)));
> > > + /* oris reg,reg,(op)@h */
> > > + patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ORIS |
> > > ___PPC_RA(reg) |
> > > + ___PPC_RS(reg) | ((val >> 16) & 0xffff)));
> > > addr++;
> > >
> > > - /* ori r3,r3,(op)@l */
> > > - patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ORI |
> > > ___PPC_RA(3) |
> > > - ___PPC_RS(3) | (val & 0xffff)));
> > > + /* ori reg,reg,(op)@l */
> > > + patch_instruction((struct ppc_inst *)addr, ppc_inst(PPC_INST_ORI |
> > > ___PPC_RA(reg) |
> > > + ___PPC_RS(reg) | (val & 0xffff)));
> > > }
> > >
> > > 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;
> > > @@ -240,7 +240,7 @@ int arch_prepare_optimized_kprobe(struct
> > > optimized_kprobe
> > > *op, struct kprobe *p)
> > > * Fixup the template with instructions to:
> > > * 1. load the address of the actual probepoint
> > > */
> > > - patch_imm64_load_insns((unsigned long)op, buff + TMPL_OP_IDX);
> > > + patch_imm64_load_insns((unsigned long)op, 3, buff + TMPL_OP_IDX);
> > >
> > > /*
> > > * 2. branch to optimized_callback() and emulate_step()
> > > @@ -271,7 +271,11 @@ 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),
> >
> > did we check building for ppc32 ?
> Yeah I need to do so.
> > I doubt we might hit build failure as `ppc_inst_suffix()` macro is not
> > defined.
> >
> >
> > > + 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/kernel/trace/ftrace.c
> > > b/arch/powerpc/kernel/trace/ftrace.c
> > > index e78742613b36..16041a5c86d5 100644
> > > --- a/arch/powerpc/kernel/trace/ftrace.c
> > > +++ b/arch/powerpc/kernel/trace/ftrace.c
> > > @@ -41,11 +41,35 @@
> > > #define NUM_FTRACE_TRAMPS 8
> > > static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
> > >
> > > +#ifdef __powerpc64__
> > > static long
> > > probe_kernel_read_inst(struct ppc_inst *inst, const void *src)
> > > {
> > > - return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE);
> > > + u32 val, suffix = 0;
> >
> > don't we need to initialize suffix with 0xff ?
> Good catch, that was causing problems.
Also we can do,
if ((val >> 26) == 1)
{
err = probe_kernel_read((void *)&suffix,
src + 4, MCOUNT_INSN_SIZE);
if (err)
return err;
*inst = ppc_inst_prefix(val, suffix);
}
else
*inst = ppc_inst(val);
to explicitly show a non-prefixed instruction and we do not have to
initialize suffix to 0xff, as ppc_inst() would take care.
-- Bala
> >
> > > + long err;
> > > +
> > > + err = probe_kernel_read((void *)&val,
> > > + src, sizeof(val));
> > > + if (err)
> > > + return err;
> > > +
> > > + if ((val >> 26) == 1)
> > > + err = probe_kernel_read((void *)&suffix,
> > > + src + 4, MCOUNT_INSN_SIZE);
> > > + if (err)
> > > + return err;
> > > +
> > > + *inst = ppc_inst_prefix(val, suffix);
> > > +
> > > + return 0;
> > > }
> > > +#else
> > > +static long
> > > +probe_kernel_read_inst(struct ppc_inst *inst, const void *src)
> > > +{
> > > + return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE)
> > > +}
> > > +#endif
> > >
> > > static struct ppc_inst
> > > ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
> > > diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-
> > > patching.c
> > > index c329ad657302..b4007e03d8fa 100644
> > > --- a/arch/powerpc/lib/code-patching.c
> > > +++ b/arch/powerpc/lib/code-patching.c
> > > @@ -24,12 +24,19 @@ 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 (err)
> > > - return err;
> > > -
> > > - asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r"
> > > (patch_addr),
> > > - "r"
> > > (exec_addr));
> > > + if (!ppc_inst_prefixed(instr)) {
> > > + __put_user_asm(ppc_inst_val(instr), patch_addr, err,
> > > "stw");
> > > + if (err)
> > > + return err;
> > > + asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r"
> > > (patch_addr),
> > > + "r"
> > > (exec_addr));
> > > + } else {
> > > + __put_user_asm((u64)ppc_inst_suffix(instr) << 32 |
> > > ppc_inst_val(instr), patch_addr, err, "std");
> > > + if (err)
> > > + return err;
> > > + asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r"
> > > (patch_addr),
> > > + "r"
> > > (exec_addr));
> > > + }
> >
> > can we keep these 2 lines out of conditions as it remains to be the same ?
> True.
> > if (err)
> > return err;
> > asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr), "r"
> > (exec_addr));
> >
> >
> > > return 0;
> > > }
> > > diff --git a/arch/powerpc/lib/feature-fixups.c
> > > b/arch/powerpc/lib/feature-
> > > fixups.c
> > > index f00dd13b1c3c..5519cec83cc8 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/sstep.c b/arch/powerpc/lib/sstep.c
> > > index 52ddd3122dc8..8b285bf11218 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);
> >
> > same here, I doubt it might break for ppc32.
> Yeah I need to work on ppc32.
> >
> > -- Bala
> > > +
> > > op->type = COMPUTE;
> > >
> > > opcode = word >> 26;
> > > diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> > > index 6f3bcdcfc9c7..b704aebb099a 100644
> > > --- a/arch/powerpc/xmon/xmon.c
> > > +++ b/arch/powerpc/xmon/xmon.c
> > > @@ -761,8 +761,8 @@ 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;
> > > }
> > > @@ -863,7 +863,7 @@ static struct bpt *in_breakpoint_table(unsigned long
> > > nip,
> > > unsigned long *offp)
> > > if (off >= sizeof(bpt_table))
> > > return NULL;
> > > *offp = off % BPT_SIZE;
> > > - if (*offp != 0 && *offp != 4)
> > > + if (*offp != 0 && *offp != 4 && *offp != 8)
> > > return NULL;
> > > return bpts + (off / BPT_SIZE);
> > > }
> > > diff --git a/arch/powerpc/xmon/xmon_bpts.S
> > > b/arch/powerpc/xmon/xmon_bpts.S
> > > index ebb2dbc70ca8..09058eb6abbd 100644
> > > --- a/arch/powerpc/xmon/xmon_bpts.S
> > > +++ b/arch/powerpc/xmon/xmon_bpts.S
> > > @@ -3,6 +3,8 @@
> > > #include <asm/asm-compat.h>
> > > #include "xmon_bpts.h"
> > >
> > > +/* Prefixed instructions can not cross 64 byte boundaries */
> > > +.align 6
> > > .global bpt_table
> > > bpt_table:
> > > - .space NBPTS * 8
> > > + .space NBPTS * 16
