[PATCH V3 05/14] tools/perf: Add disasm_line__parse to parse raw instruction for powerpc

Athira Rajeev
2024-06-01T06:10:25Z

Currently, the perf tool infrastructure disasm_line__parse function to
parse disassembled line.

Example snippet from objdump:
objdump --start-address= --stop-address= -d --no-show-raw-insn -C <vmlinux>

c0000000010224b4: lwz r10,0(r9)

This line "lwz r10,0(r9)" is parsed to extract instruction name,
registers names and offset. In powerpc, the approach for data type
profiling uses raw instruction instead of result from objdump to identify
the instruction category and extract the source/target registers.

Example: 38 01 81 e8 ld r4,312(r1)

Here "38 01 81 e8" is the raw instruction representation. Add function
"disasm_line__parse_powerpc" to handle parsing of raw instruction. Also
update "struct ins" and "struct ins_operands" to save "opcode" and
binary code. With the change, function captures:

line -> "38 01 81 e8 ld r4,312(r1)"
opcode and raw instruction "38 01 81 e8"

Raw instruction is used later to extract the reg/offset fields. Macros
are added to extract opcode and register fields. "struct ins_operands"
and "struct ins" is updated to carry opcode and raw instruction binary
code (raw_insn). Function "disasm_line__parse_powerpc fills the raw
instruction hex value and opcode in newly added fields. There is no
changes in existing code paths, which parses the disassembled code.
The architecture using the instruction name and present approach is
not altered. Since this approach targets powerpc, the macro
implementation is added for powerpc as of now.

Since the disasm_line__parse is used in other cases (perf annotate) and
not only data tye profiling, the powerpc callback includes changes to
work with binary code as well as mneumonic representation. Also in case
if the DSO read fails and libcapstone is not supported, the approach
fallback to use objdump as option. Hence as option, patch has changes to
ensure objdump option also works well.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
---
tools/include/linux/string.h | 2 +
tools/lib/string.c | 13 ++++
.../perf/arch/powerpc/annotate/instructions.c | 1 +
tools/perf/arch/powerpc/util/dwarf-regs.c | 9 +++
tools/perf/util/disasm.c | 63 ++++++++++++++++++-
tools/perf/util/disasm.h | 7 +++
6 files changed, 94 insertions(+), 1 deletion(-)

diff --git a/tools/include/linux/string.h b/tools/include/linux/string.h
index db5c99318c79..0acb1fc14e19 100644
--- a/tools/include/linux/string.h
+++ b/tools/include/linux/string.h
@@ -46,5 +46,7 @@ extern char * __must_check skip_spaces(const char *);

extern char *strim(char *);

+extern void remove_spaces(char *s);
+
extern void *memchr_inv(const void *start, int c, size_t bytes);
#endif /* _TOOLS_LINUX_STRING_H_ */
diff --git a/tools/lib/string.c b/tools/lib/string.c
index 8b6892f959ab..3126d2cff716 100644
--- a/tools/lib/string.c
+++ b/tools/lib/string.c
@@ -153,6 +153,19 @@ char *strim(char *s)
return skip_spaces(s);
}

+/*
+ * remove_spaces - Removes whitespaces from @s
+ */
+void remove_spaces(char *s)
+{
+ char *d = s;
+
+ do {
+ while (*d == ' ')
+ ++d;
+ } while ((*s++ = *d++));
+}
+
/**
* strreplace - Replace all occurrences of character in string.
* @s: The string to operate on.
diff --git a/tools/perf/arch/powerpc/annotate/instructions.c b/tools/perf/arch/powerpc/annotate/instructions.c
index a3f423c27cae..d57fd023ef9c 100644
--- a/tools/perf/arch/powerpc/annotate/instructions.c
+++ b/tools/perf/arch/powerpc/annotate/instructions.c
@@ -55,6 +55,7 @@ static int powerpc__annotate_init(struct arch *arch, char *cpuid __maybe_unused)
arch->initialized = true;
arch->associate_instruction_ops = powerpc__associate_instruction_ops;
arch->objdump.comment_char = '#';
+ annotate_opts.show_asm_raw = true;
}

return 0;
diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
index 0c4f4caf53ac..430623ca5612 100644
--- a/tools/perf/arch/powerpc/util/dwarf-regs.c
+++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
@@ -98,3 +98,12 @@ int regs_query_register_offset(const char *name)
return roff->ptregs_offset;
return -EINVAL;
}
+
+#define PPC_OP(op) (((op) >> 26) & 0x3F)
+#define PPC_RA(a) (((a) >> 16) & 0x1f)
+#define PPC_RT(t) (((t) >> 21) & 0x1f)
+#define PPC_RB(b) (((b) >> 11) & 0x1f)
+#define PPC_D(D) ((D) & 0xfffe)
+#define PPC_DS(DS) ((DS) & 0xfffc)
+#define OP_LD 58
+#define OP_STD 62
diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index 3cd187f08193..61f0f1656f82 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -45,6 +45,7 @@ static int call__scnprintf(struct ins *ins, char *bf, size_t size,

static void ins__sort(struct arch *arch);
static int disasm_line__parse(char *line, const char **namep, char **rawp);
+static int disasm_line__parse_powerpc(struct disasm_line *dl);

static __attribute__((constructor)) void symbol__init_regexpr(void)
{
@@ -844,6 +845,63 @@ static int disasm_line__parse(char *line, const char **namep, char **rawp)
return -1;
}

+/*
+ * Parses the result captured from symbol__disassemble_*
+ * Example, line read from DSO file in powerpc:
+ * line: 38 01 81 e8
+ * opcode: fetched from arch specific get_opcode_insn
+ * rawp_insn: e8810138
+ *
+ * rawp_insn is used later to extract the reg/offset fields
+ */
+#define PPC_OP(op) (((op) >> 26) & 0x3F)
+
+static int disasm_line__parse_powerpc(struct disasm_line *dl)
+{
+ char *line = dl->al.line;
+ const char **namep = &dl->ins.name;
+ char **rawp = &dl->ops.raw;
+ char tmp, *tmp_opcode, *name_opcode = skip_spaces(line);
+ char *name = skip_spaces(name_opcode + 11);
+ int objdump = 0;
+
+ if (strlen(line) > 11)
+ objdump = 1;
+
+ if (name_opcode[0] == '\0')
+ return -1;
+
+ if (objdump) {
+ *rawp = name + 1;
+ while ((*rawp)[0] != '\0' && !isspace((*rawp)[0]))
+ ++*rawp;
+ tmp = (*rawp)[0];
+ (*rawp)[0] = '\0';
+
+ *namep = strdup(name);
+ if (*namep == NULL)
+ return -1;
+
+ (*rawp)[0] = tmp;
+ *rawp = strim(*rawp);
+ } else
+ *namep = "";
+
+ tmp_opcode = strdup(name_opcode);
+ tmp_opcode[11] = '\0';
+ remove_spaces(tmp_opcode);
+
+ dl->ins.opcode = PPC_OP(strtol(tmp_opcode, NULL, 16));
+ if (objdump)
+ dl->ins.opcode = PPC_OP(be32_to_cpu(strtol(tmp_opcode, NULL, 16)));
+ dl->ops.opcode = dl->ins.opcode;
+
+ dl->ops.raw_insn = strtol(tmp_opcode, NULL, 16);
+ if (objdump)
+ dl->ops.raw_insn = be32_to_cpu(strtol(tmp_opcode, NULL, 16));
+ return 0;
+}
+
static void annotation_line__init(struct annotation_line *al,
struct annotate_args *args,
int nr)
@@ -897,7 +955,10 @@ struct disasm_line *disasm_line__new(struct annotate_args *args)
goto out_delete;

if (args->offset != -1) {
- if (disasm_line__parse(dl->al.line, &dl->ins.name, &dl->ops.raw) < 0)
+ if (arch__is(args->arch, "powerpc")) {
+ if (disasm_line__parse_powerpc(dl) < 0)
+ goto out_free_line;
+ } else if (disasm_line__parse(dl->al.line, &dl->ins.name, &dl->ops.raw) < 0)
goto out_free_line;

disasm_line__init_ins(dl, args->arch, &args->ms);
diff --git a/tools/perf/util/disasm.h b/tools/perf/util/disasm.h
index 718177fa4775..a391e1bb81f7 100644
--- a/tools/perf/util/disasm.h
+++ b/tools/perf/util/disasm.h
@@ -43,14 +43,19 @@ struct arch {

struct ins {
const char *name;
+ int opcode;
struct ins_ops *ops;
};

struct ins_operands {
char *raw;
+ int raw_insn;
+ int opcode;
struct {
char *raw;
char *name;
+ int opcode;
+ int raw_insn;
struct symbol *sym;
u64 addr;
s64 offset;
@@ -62,6 +67,8 @@ struct ins_operands {
struct {
char *raw;
char *name;
+ int opcode;
+ int raw_insn;
u64 addr;
bool multi_regs;
} source;
--
2.43.0