[PATCH 11/14] perf annotate: Parse x86 segment register location

From: Namhyung Kim
Date: Fri Feb 16 2024 - 19:06:38 EST


Add a segment field in the struct annotated_insn_loc and save it for the
segment based addressing like %gs:0x28. For simplicity it now handles
%gs register only.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/annotate.c | 21 +++++++++++++++++++--
tools/perf/util/annotate.h | 13 +++++++++++++
2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 89a8d57b1bf7..86ac44c476bf 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -3557,6 +3557,12 @@ static int extract_reg_offset(struct arch *arch, const char *str,
* %gs:0x18(%rbx). In that case it should skip the part.
*/
if (*str == arch->objdump.register_char) {
+ if (arch__is(arch, "x86")) {
+ /* FIXME: Handle other segment registers */
+ if (!strncmp(str, "%gs:", 4))
+ op_loc->segment = INSN_SEG_X86_GS;
+ }
+
while (*str && !isdigit(*str) &&
*str != arch->objdump.memory_ref_char)
str++;
@@ -3653,8 +3659,19 @@ int annotate_get_insn_location(struct arch *arch, struct disasm_line *dl,
op_loc->multi_regs = multi_regs;
extract_reg_offset(arch, insn_str, op_loc);
} else {
- char *s = strdup(insn_str);
+ char *s;
+
+ if (arch__is(arch, "x86")) {
+ /* FIXME: Handle other segment registers */
+ if (!strncmp(insn_str, "%gs:", 4)) {
+ op_loc->segment = INSN_SEG_X86_GS;
+ op_loc->offset = strtol(insn_str + 4,
+ NULL, 0);
+ continue;
+ }
+ }

+ s = strdup(insn_str);
if (s) {
op_loc->reg1 = get_dwarf_regnum(s, 0);
free(s);
@@ -3875,7 +3892,7 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
.op = op_loc,
};

- if (!op_loc->mem_ref)
+ if (!op_loc->mem_ref && op_loc->segment == INSN_SEG_NONE)
continue;

/* Recalculate IP because of LOCK prefix or insn fusion */
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index b460785111a1..2bd654620de3 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -446,6 +446,7 @@ int annotate_check_args(void);
* @reg1: First register in the operand
* @reg2: Second register in the operand
* @offset: Memory access offset in the operand
+ * @segment: Segment selector register
* @mem_ref: Whether the operand accesses memory
* @multi_regs: Whether the second register is used
*/
@@ -453,6 +454,7 @@ struct annotated_op_loc {
int reg1;
int reg2;
int offset;
+ u8 segment;
bool mem_ref;
bool multi_regs;
};
@@ -464,6 +466,17 @@ enum annotated_insn_ops {
INSN_OP_MAX,
};

+enum annotated_x86_segment {
+ INSN_SEG_NONE = 0,
+
+ INSN_SEG_X86_CS,
+ INSN_SEG_X86_DS,
+ INSN_SEG_X86_ES,
+ INSN_SEG_X86_FS,
+ INSN_SEG_X86_GS,
+ INSN_SEG_X86_SS,
+};
+
/**
* struct annotated_insn_loc - Location info of instruction
* @ops: Array of location info for source and target operands
--
2.44.0.rc0.258.g7320e95886-goog