From: Tengda Wu <wutengda@huaweicloud.com>
To: Namhyung Kim <namhyung@kernel.org>,
james.clark@linaro.org, xueshuai@linux.alibaba.com,
Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
leo.yan@linux.dev, Li Huafei <lihuafei1@huawei.com>,
Ian Rogers <irogers@google.com>,
Kim Phillips <kim.phillips@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ingo Molnar <mingo@redhat.com>, Bill Wendling <morbo@google.com>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Zecheng Li <zli94@ncsu.edu>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
llvm@lists.linux.dev, Tengda Wu <wutengda@huaweicloud.com>
Subject: [PATCH v8 03/15] perf annotate-data: Add arch_get_reg_offset helper
Date: Tue, 20 Oct 2026 13:44:59 +0000 [thread overview]
Message-ID: <f22d02ca275d647abfa459bdccd89cb23e63019f.1792411435.git.wutengda@huaweicloud.com> (raw)
In-Reply-To: <cover.1792411435.git.wutengda@huaweicloud.com>
Add a helper to compute the effective offset from a base register
for instruction operands. Currently handles arm64 addressing modes
including post-indexed, single-register, SIB-style indexed with
shift/extension, and constant-offset register pairs.
Fallback to instruction's raw offset for other architectures.
Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
---
tools/perf/util/annotate-data.c | 115 ++++++++++++++++++++++++++------
tools/perf/util/annotate-data.h | 4 +-
2 files changed, 98 insertions(+), 21 deletions(-)
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 398795ba3694..24d82739b2ec 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -1241,6 +1241,74 @@ static void setup_stack_canary(struct data_loc_info *dloc)
}
}
+int arch_get_reg_offset(const struct arch *arch, struct annotated_op_loc *op_loc,
+ int breg, struct type_state *state, bool apply_index,
+ int *offset)
+{
+ if (arch__is_arm64(arch)) {
+ int reg2;
+
+ /* Post-indexed addressing: offset is 0 when not applying index */
+ if (op_loc->addr_mode == PERF_AAM_POST_INDEX && !apply_index) {
+ *offset = 0;
+ return 0;
+ }
+
+ /* Single-register addressing: return the stored offset directly */
+ if (!op_loc->multi_regs) {
+ *offset = op_loc->offset;
+ return 0;
+ }
+
+ /*
+ * SIB (Scale-Index-Base) style indexed addressing, e.g.:
+ * Array element load: ldr dst, [base, index, lsl #3]
+ * Array element load: ldr dst, [base, index, uxtw #3]
+ * Array address calc: add dst, base, index lsl #3
+ *
+ * The index reg only computes element offset without modifying
+ * the underlying data type; the dst type is inherited from base.
+ * Therefore, the base reg offset can be treated as 0.
+ */
+ if (op_loc->extend_type || op_loc->shift_type) {
+ /* A memory reference implies breg is a pointer. */
+ if (op_loc->mem_ref) {
+ *offset = 0;
+ return 0;
+ }
+ /*
+ * Otherwise, require breg to be a known pointer to avoid
+ * treating integer arithmetic as indexed address calculation.
+ */
+ if (has_reg_type(state, breg) && state->regs[breg].ok &&
+ (state->regs[breg].kind == TSR_KIND_POINTER ||
+ (state->regs[breg].kind == TSR_KIND_TYPE &&
+ dwarf_tag(&state->regs[breg].type) == DW_TAG_pointer_type))) {
+ *offset = 0;
+ return 0;
+ }
+ return -1;
+ }
+
+ /*
+ * For register-based addressing without shift/extension,
+ * reg2 may be a constant offset. Use its value as the offset
+ * from the base register.
+ */
+ reg2 = op_loc->reg1 == breg ? op_loc->reg2 : op_loc->reg1;
+ if (has_reg_type(state, reg2) && state->regs[reg2].ok &&
+ state->regs[reg2].kind == TSR_KIND_CONST) {
+ *offset = (s64)state->regs[reg2].imm_value;
+ return 0;
+ }
+
+ return -1;
+ }
+
+ *offset = op_loc->offset;
+ return 0;
+}
+
/*
* It's at the target address, check if it has a matching type.
* It returns PERF_TMR_BAIL_OUT when it looks up per-cpu variables which
@@ -1254,18 +1322,25 @@ static enum type_match_result check_matching_type(struct type_state *state,
{
u32 insn_offset = dl->al.offset;
int reg = dloc->op->reg1;
- int offset = dloc->op->offset;
- const char *offset_sign = "";
+ int offset;
+ const char *offset_sign;
bool retry = true;
- if (offset < 0) {
- offset = -offset;
- offset_sign = "-";
+again:
+ if (arch_get_reg_offset(dloc->arch, dloc->op, reg, state, false, &offset)) {
+ /*
+ * Fall back to the instruction's offset. This prevents the
+ * register type of the instruction from being completely lost.
+ * Compared to dropping this type inference entirely, providing
+ * a rough type hint is likely more useful.
+ */
+ offset = dloc->op->offset;
}
-again:
+ offset_sign = offset < 0 ? "-" : "";
+
pr_debug_dtp("chk [%x] reg%d offset=%s%#x ok=%d kind=%d ",
- insn_offset, reg, offset_sign, offset,
+ insn_offset, reg, offset_sign, abs(offset),
state->regs[reg].ok, state->regs[reg].kind);
if (!state->regs[reg].ok)
@@ -1288,7 +1363,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
*/
ptr_type = die_get_pointer_type(&state->regs[reg].type, &ptr_die);
if (!ptr_type) {
- if (dloc->op->offset < 0 && reg != state->stack_reg)
+ if (offset < 0 && reg != state->stack_reg)
goto check_kernel;
return PERF_TMR_NO_POINTER;
@@ -1298,7 +1373,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
if (__die_get_real_type(ptr_type, type_die) == NULL)
return PERF_TMR_NO_POINTER;
- dloc->type_offset = dloc->op->offset + state->regs[reg].offset;
+ dloc->type_offset = offset + state->regs[reg].offset;
if (dwarf_tag(type_die) == DW_TAG_typedef)
die_get_real_type(type_die, &sized_type);
@@ -1322,7 +1397,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
*/
*type_die = state->regs[reg].type;
- dloc->type_offset = dloc->op->offset + state->regs[reg].offset;
+ dloc->type_offset = offset + state->regs[reg].offset;
return check_type_offset(type_die, dloc->type_offset);
}
@@ -1336,7 +1411,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
*/
*type_die = state->regs[reg].type;
- dloc->type_offset = dloc->op->offset;
+ dloc->type_offset = offset;
if (check_type_offset(type_die, dloc->type_offset) != PERF_TMR_OK)
return PERF_TMR_BAIL_OUT;
@@ -1358,7 +1433,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
}
if (state->regs[reg].kind == TSR_KIND_PERCPU_BASE) {
- u64 var_addr = dloc->op->offset;
+ u64 var_addr = (s64) offset;
int var_offset;
pr_debug_dtp("percpu var");
@@ -1385,7 +1460,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
if (state->regs[reg].kind == TSR_KIND_CONST &&
dso__kernel(map__dso(dloc->ms->map))) {
- if (dloc->op->offset < 0 && reg != state->stack_reg && reg != dloc->fbreg)
+ if (offset < 0 && reg != state->stack_reg && reg != dloc->fbreg)
goto check_kernel;
}
check_non_register:
@@ -1394,7 +1469,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
pr_debug_dtp("%s", reg == dloc->fbreg ? "fbreg" : "stack");
- stack = find_stack_state(state, dloc->type_offset);
+ stack = find_stack_state(state, offset);
if (stack == NULL) {
if (retry) {
pr_debug_dtp(" : retry\n");
@@ -1417,7 +1492,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
*type_die = stack->type;
/* Update the type offset from the start of slot */
- dloc->type_offset -= stack->offset;
+ dloc->type_offset = offset - stack->offset;
return PERF_TMR_OK;
}
@@ -1435,7 +1510,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
if (reg != fbreg)
return PERF_TMR_NO_TYPE;
- stack = find_stack_state(state, dloc->type_offset - fboff);
+ stack = find_stack_state(state, offset - fboff);
if (stack == NULL) {
if (retry) {
pr_debug_dtp(" : retry\n");
@@ -1458,7 +1533,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
*type_die = stack->type;
/* Update the type offset from the start of slot */
- dloc->type_offset -= fboff + stack->offset;
+ dloc->type_offset = offset - fboff - stack->offset;
return PERF_TMR_OK;
}
@@ -1472,7 +1547,7 @@ static enum type_match_result check_matching_type(struct type_state *state,
arch__is_x86(dloc->arch)) {
pr_debug_dtp("this-cpu var");
- addr = dloc->op->offset;
+ addr = (s64) offset;
if (get_global_var_type(cu_die, dloc, dloc->ip, addr,
&offset, type_die)) {
@@ -1483,8 +1558,8 @@ static enum type_match_result check_matching_type(struct type_state *state,
}
/* Access to global variable like "-0x7dcf0500(,%rdx,8)" */
- if (dloc->op->offset < 0 && reg != state->stack_reg) {
- addr = (s64) dloc->op->offset;
+ if (offset < 0 && reg != state->stack_reg) {
+ addr = (s64) offset;
if (get_global_var_type(cu_die, dloc, dloc->ip, addr,
&offset, type_die)) {
diff --git a/tools/perf/util/annotate-data.h b/tools/perf/util/annotate-data.h
index d0dc056fb13a..453efdf6afa6 100644
--- a/tools/perf/util/annotate-data.h
+++ b/tools/perf/util/annotate-data.h
@@ -274,7 +274,9 @@ bool get_global_var_type(Dwarf_Die *cu_die, struct data_loc_info *dloc,
bool get_global_var_info(struct data_loc_info *dloc, u64 addr,
const char **var_name, int *var_offset);
void pr_debug_type_name(Dwarf_Die *die, enum type_state_kind kind);
-
+int arch_get_reg_offset(const struct arch *arch, struct annotated_op_loc *op_loc,
+ int breg, struct type_state *state, bool apply_index,
+ int *offset);
#else /* HAVE_LIBDW_SUPPORT */
static inline struct annotated_data_type *
--
2.34.1
next prev parent reply other threads:[~2026-10-20 13:46 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-20 13:44 [PATCH v8 00/15] perf annotate arm64: Support instruction tracking for data type profiling Tengda Wu
2026-10-20 13:44 ` [PATCH v8 01/15] perf annotate-data: Extract invalidate_reg_state() as a common helper Tengda Wu
2026-10-20 13:44 ` [PATCH v8 02/15] perf annotate-arm64: Enable instruction tracking support Tengda Wu
2026-10-20 13:44 ` Tengda Wu [this message]
2026-10-20 13:45 ` [PATCH v8 04/15] perf annotate-arm64: Track return type after call instructions Tengda Wu
2026-10-20 13:45 ` [PATCH v8 05/15] perf annotate-arm64: Support load instruction tracking Tengda Wu
2026-10-20 13:45 ` [PATCH v8 06/15] perf annotate-arm64: Support store " Tengda Wu
2026-10-20 13:45 ` [PATCH v8 07/15] perf annotate-data: Expand type_state_reg imm_value to u64 Tengda Wu
2026-10-20 13:45 ` [PATCH v8 08/15] perf annotate-data: Track imm_value for stack variables Tengda Wu
2026-10-20 13:45 ` [PATCH v8 09/15] perf annotate-x86: Delete stale stack state on store of untracked register Tengda Wu
2026-10-20 13:45 ` [PATCH v8 10/15] perf annotate-arm64: Support stack variable tracking Tengda Wu
2026-10-20 13:45 ` [PATCH v8 11/15] perf annotate-arm64: Support 'mov' instruction tracking Tengda Wu
2026-10-20 13:45 ` [PATCH v8 12/15] perf annotate-arm64: Support 'add' " Tengda Wu
2026-10-20 13:45 ` [PATCH v8 13/15] perf annotate-arm64: Support 'adrp' instruction to track global variables Tengda Wu
2026-10-20 13:45 ` [PATCH v8 14/15] perf annotate-arm64: Support per-cpu variable access tracking Tengda Wu
2026-10-20 13:45 ` [PATCH v8 15/15] perf annotate-arm64: Support 'mrs' instruction to track 'current' pointer Tengda Wu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f22d02ca275d647abfa459bdccd89cb23e63019f.1792411435.git.wutengda@huaweicloud.com \
--to=wutengda@huaweicloud.com \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=irogers@google.com \
--cc=james.clark@linaro.org \
--cc=kim.phillips@arm.com \
--cc=leo.yan@linux.dev \
--cc=lihuafei1@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=morbo@google.com \
--cc=namhyung@kernel.org \
--cc=nick.desaulniers+lkml@gmail.com \
--cc=peterz@infradead.org \
--cc=xueshuai@linux.alibaba.com \
--cc=zli94@ncsu.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®