[PATCH 1/4] powerpc: Add a ppc_inst_as_str() helper
Jordan Niethe
jniethe5 at gmail.com
Tue Jun 2 15:27:25 AEST 2020
There are quite a few places where instructions are printed, this is
done using a '%x' format specifier. With the introduction of prefixed
instructions, this does not work well. Currently in these places,
ppc_inst_val() is used for the value for %x so only the first word of
prefixed instructions are printed.
When the instructions are word instructions, only a single word should
be printed. For prefixed instructions both the prefix and suffix should
be printed. To accommodate both of these situations, instead of a '%x'
specifier use '%s' and introduce a helper, __ppc_inst_as_str() which
returns a char *. The char * __ppc_inst_as_str() returns is buffer that
is passed to it by the caller.
It is cumbersome to require every caller of __ppc_inst_as_str() to now
declare a buffer. To make it more convenient to use __ppc_inst_as_str(),
wrap it in a macro that uses a compound statement to allocate a buffer
on the caller's stack before calling it.
Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
---
arch/powerpc/include/asm/inst.h | 19 +++++++++++++++++++
arch/powerpc/kernel/kprobes.c | 2 +-
arch/powerpc/kernel/trace/ftrace.c | 26 +++++++++++++-------------
arch/powerpc/lib/test_emulate_step.c | 4 ++--
arch/powerpc/xmon/xmon.c | 2 +-
5 files changed, 36 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 45f3ec868258..3df7806e6dc3 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -122,6 +122,25 @@ static inline u64 ppc_inst_as_u64(struct ppc_inst x)
#endif
}
+#define PPC_INST_STR_LEN sizeof("0x00000000 0x00000000")
+
+static inline char *__ppc_inst_as_str(char str[PPC_INST_STR_LEN], struct ppc_inst x)
+{
+ if (ppc_inst_prefixed(x))
+ sprintf(str, "0x%08x 0x%08x", ppc_inst_val(x), ppc_inst_suffix(x));
+ else
+ sprintf(str, "0x%08x", ppc_inst_val(x));
+
+ return str;
+}
+
+#define ppc_inst_as_str(x) \
+({ \
+ char __str[PPC_INST_STR_LEN]; \
+ __ppc_inst_as_str(__str, x); \
+ __str; \
+})
+
int probe_user_read_inst(struct ppc_inst *inst,
struct ppc_inst __user *nip);
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 227510df8c55..d0797171dba3 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -244,7 +244,7 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
* So, we should never get here... but, its still
* good to catch them, just in case...
*/
- printk("Can't step on instruction %x\n", ppc_inst_val(insn));
+ printk("Can't step on instruction %s\n", ppc_inst_as_str(insn));
BUG();
} else {
/*
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 5e399628f51a..da11a26d8213 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -73,8 +73,8 @@ ftrace_modify_code(unsigned long ip, struct ppc_inst old, struct ppc_inst new)
/* Make sure it is what we expect it to be */
if (!ppc_inst_equal(replaced, old)) {
- pr_err("%p: replaced (%#x) != old (%#x)",
- (void *)ip, ppc_inst_val(replaced), ppc_inst_val(old));
+ pr_err("%p: replaced (%s) != old (%s)",
+ (void *)ip, ppc_inst_as_str(replaced), ppc_inst_as_str(old));
return -EINVAL;
}
@@ -137,7 +137,7 @@ __ftrace_make_nop(struct module *mod,
/* Make sure that that this is still a 24bit jump */
if (!is_bl_op(op)) {
- pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));
+ pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
return -EINVAL;
}
@@ -172,8 +172,8 @@ __ftrace_make_nop(struct module *mod,
/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
if (!ppc_inst_equal(op, ppc_inst(PPC_INST_MFLR)) &&
!ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
- pr_err("Unexpected instruction %08x around bl _mcount\n",
- ppc_inst_val(op));
+ pr_err("Unexpected instruction %s around bl _mcount\n",
+ ppc_inst_as_str(op));
return -EINVAL;
}
#else
@@ -203,7 +203,7 @@ __ftrace_make_nop(struct module *mod,
}
if (!ppc_inst_equal(op, ppc_inst(PPC_INST_LD_TOC))) {
- pr_err("Expected %08x found %08x\n", PPC_INST_LD_TOC, ppc_inst_val(op));
+ pr_err("Expected %08x found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));
return -EINVAL;
}
#endif /* CONFIG_MPROFILE_KERNEL */
@@ -231,7 +231,7 @@ __ftrace_make_nop(struct module *mod,
/* Make sure that that this is still a 24bit jump */
if (!is_bl_op(op)) {
- pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));
+ pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
return -EINVAL;
}
@@ -406,7 +406,7 @@ static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec, unsigned long addr)
/* Make sure that that this is still a 24bit jump */
if (!is_bl_op(op)) {
- pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));
+ pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
return -EINVAL;
}
@@ -533,8 +533,8 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
return -EFAULT;
if (!expected_nop_sequence(ip, op[0], op[1])) {
- pr_err("Unexpected call sequence at %p: %x %x\n",
- ip, ppc_inst_val(op[0]), ppc_inst_val(op[1]));
+ pr_err("Unexpected call sequence at %p: %s %s\n",
+ ip, ppc_inst_as_str(op[0]), ppc_inst_as_str(op[1]));
return -EINVAL;
}
@@ -597,7 +597,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
/* It should be pointing to a nop */
if (!ppc_inst_equal(op, ppc_inst(PPC_INST_NOP))) {
- pr_err("Expected NOP but have %x\n", ppc_inst_val(op));
+ pr_err("Expected NOP but have %s\n", ppc_inst_as_str(op));
return -EINVAL;
}
@@ -654,7 +654,7 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
}
if (!ppc_inst_equal(op, ppc_inst(PPC_INST_NOP))) {
- pr_err("Unexpected call sequence at %p: %x\n", ip, ppc_inst_val(op));
+ pr_err("Unexpected call sequence at %p: %s\n", ip, ppc_inst_as_str(op));
return -EINVAL;
}
@@ -733,7 +733,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
/* Make sure that that this is still a 24bit jump */
if (!is_bl_op(op)) {
- pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));
+ pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
return -EINVAL;
}
diff --git a/arch/powerpc/lib/test_emulate_step.c b/arch/powerpc/lib/test_emulate_step.c
index 46af80279ebc..5fb6f5267d70 100644
--- a/arch/powerpc/lib/test_emulate_step.c
+++ b/arch/powerpc/lib/test_emulate_step.c
@@ -852,7 +852,7 @@ static int __init emulate_compute_instr(struct pt_regs *regs,
if (analyse_instr(&op, regs, instr) != 1 ||
GETTYPE(op.type) != COMPUTE) {
- pr_info("emulation failed, instruction = 0x%08x\n", ppc_inst_val(instr));
+ pr_info("execution failed, instruction = %s\n", ppc_inst_as_str(instr));
return -EFAULT;
}
@@ -872,7 +872,7 @@ static int __init execute_compute_instr(struct pt_regs *regs,
/* Patch the NOP with the actual instruction */
patch_instruction_site(&patch__exec_instr, instr);
if (exec_instr(regs)) {
- pr_info("execution failed, instruction = 0x%08x\n", ppc_inst_val(instr));
+ pr_info("execution failed, instruction = %s\n", ppc_inst_as_str(instr));
return -EFAULT;
}
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 16ee6639a60c..1dd3bf02021b 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2958,7 +2958,7 @@ generic_inst_dump(unsigned long adr, long count, int praddr,
dotted = 0;
last_inst = inst;
if (praddr)
- printf(REG" %.8x", adr, ppc_inst_val(inst));
+ printf(REG" %s", adr, ppc_inst_as_str(inst));
printf("\t");
dump_func(ppc_inst_val(inst), adr);
printf("\n");
--
2.17.1
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