[PATCH v3 06/20] perf dwarf-regs: Pass ELF flags to get_dwarf_regstr

Ian Rogers
2024-10-17T02:01:06Z

Pass a flags value as architectures like csky need the flags to
determine the ABI variant.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/dwarf-regs.c | 3 ++-
tools/perf/util/include/dwarf-regs.h | 11 ++++++-----
tools/perf/util/probe-finder.c | 13 +++++++------
tools/perf/util/probe-finder.h | 3 ++-
4 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
index 1321387f6948..86b3ef638fbb 100644
--- a/tools/perf/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs.c
@@ -29,7 +29,8 @@
#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)

/* Return architecture dependent register string (for kprobe-tracer) */
-const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
+ unsigned int flags __maybe_unused)
{
switch (machine) {
case EM_NONE: /* Generic arch - use host arch */
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index ee0a734564c7..925525405e2d 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -80,12 +80,13 @@

#ifdef HAVE_LIBDW_SUPPORT
const char *get_arch_regstr(unsigned int n);
-/*
- * get_dwarf_regstr - Returns ftrace register string from DWARF regnum
- * n: DWARF register number
- * machine: ELF machine signature (EM_*)
+/**
+ * get_dwarf_regstr() - Returns ftrace register string from DWARF regnum.
+ * @n: DWARF register number.
+ * @machine: ELF machine signature (EM_*).
+ * @flags: ELF flags for things like ABI differences.
*/
-const char *get_dwarf_regstr(unsigned int n, unsigned int machine);
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags);

int get_arch_regnum(const char *name);
/*
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 8ea15a2a4397..8a932cc2f63d 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -56,7 +56,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
*/
static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
- unsigned int machine,
+ const struct probe_finder *pf,
struct probe_trace_arg *tvar)
{
Dwarf_Attribute attr;
@@ -166,7 +166,7 @@ static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
if (!tvar)
return ret2;

- regs = get_dwarf_regstr(regn, machine);
+ regs = get_dwarf_regstr(regn, pf->e_machine, pf->e_flags);
if (!regs) {
/* This should be a bug in DWARF or this tool */
pr_warning("Mapping for the register number %u "
@@ -451,7 +451,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
dwarf_diename(vr_die));

ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
- &pf->sp_die, pf->machine, pf->tvar);
+ &pf->sp_die, pf, pf->tvar);
if (ret == -ENOENT && pf->skip_empty_arg)
/* This can be found in other place. skip it */
return 0;
@@ -1134,7 +1134,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
if (gelf_getehdr(elf, &ehdr) == NULL)
return -EINVAL;

- pf->machine = ehdr.e_machine;
+ pf->e_machine = ehdr.e_machine;
+ pf->e_flags = ehdr.e_flags;

do {
GElf_Shdr shdr;
@@ -1171,7 +1172,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
(tag == DW_TAG_variable && vf->vars)) {
if (convert_variable_location(die_mem, vf->pf->addr,
vf->pf->fb_ops, &pf->sp_die,
- pf->machine, NULL) == 0) {
+ pf, /*tvar=*/NULL) == 0) {
vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
if (vf->args[vf->nargs].var == NULL) {
vf->ret = -ENOMEM;
@@ -1402,7 +1403,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
tag == DW_TAG_variable) {
ret = convert_variable_location(die_mem, af->pf.addr,
af->pf.fb_ops, &af->pf.sp_die,
- af->pf.machine, NULL);
+ &af->pf, /*tvar=*/NULL);
if (ret == 0 || ret == -ERANGE) {
int ret2;
bool externs = !af->child;
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index dfcf8cdd9e8d..be7b46ea2460 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -68,7 +68,8 @@ struct probe_finder {
/* Call Frame Information from .debug_frame. Not owned. */
Dwarf_CFI *cfi_dbg;
Dwarf_Op *fb_ops; /* Frame base attribute */
- unsigned int machine; /* Target machine arch */
+ unsigned int e_machine; /* ELF target machine arch */
+ unsigned int e_flags; /* ELF target machine flags */
struct perf_probe_arg *pvar; /* Current target variable */
struct probe_trace_arg *tvar; /* Current result variable */
bool skip_empty_arg; /* Skip non-exist args */