[PATCH v3 07/20] perf dwarf-regs: Move x86 dwarf-regs out of arch

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

Move arch/x86/util/dwarf-regs.c to util/dwarf-regs-x86.c and compile
in unconditionally. To avoid get_arch_regnum being duplicated, rename
to get_x86_regnum and add to get_dwarf_regnum switch.

For get_arch_regstr, this was unused on x86 unless the machine type
was EM_NONE. Map that case to EM_HOST and remove get_arch_regstr from
dwarf-regs-x86.c.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/arch/x86/util/Build | 3 ---
tools/perf/util/Build | 1 +
.../dwarf-regs.c => util/dwarf-regs-x86.c} | 24 +------------------
tools/perf/util/dwarf-regs.c | 17 +++++++++++++
tools/perf/util/include/dwarf-regs.h | 8 +++++++
5 files changed, 27 insertions(+), 26 deletions(-)
rename tools/perf/{arch/x86/util/dwarf-regs.c => util/dwarf-regs-x86.c} (77%)

diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build
index 9705cda4f240..70af491a6dd7 100644
--- a/tools/perf/arch/x86/util/Build
+++ b/tools/perf/arch/x86/util/Build
@@ -12,9 +12,6 @@ perf-util-y += evsel.o
perf-util-y += iostat.o
perf-util-y += env.o

-perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
-perf-util-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
-
perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 1eedead5f2f2..4c615611b9d7 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -203,6 +203,7 @@ endif
perf-util-$(CONFIG_LIBDW) += probe-finder.o
perf-util-$(CONFIG_LIBDW) += dwarf-aux.o
perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
+perf-util-$(CONFIG_LIBDW) += dwarf-regs-x86.o
perf-util-$(CONFIG_LIBDW) += debuginfo.o
perf-util-$(CONFIG_LIBDW) += annotate-data.o

diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/util/dwarf-regs-x86.c
similarity index 77%
rename from tools/perf/arch/x86/util/dwarf-regs.c
rename to tools/perf/util/dwarf-regs-x86.c
index 530905118cd4..7a55c65e8da6 100644
--- a/tools/perf/arch/x86/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs-x86.c
@@ -11,28 +11,6 @@
#include <linux/kernel.h> /* for ARRAY_SIZE */
#include <dwarf-regs.h>

-#define DEFINE_DWARF_REGSTR_TABLE 1
-#include "dwarf-regs-table.h"
-
-/* Return architecture dependent register string (for kprobe-tracer) */
-const char *get_arch_regstr(unsigned int n)
-{
-#if defined(__i386__)
- size_t len = ARRAY_SIZE(x86_32_regstr_tbl);
-#else
- size_t len = ARRAY_SIZE(x86_64_regstr_tbl);
-#endif
-
- if (n >= len)
- return NULL;
-
-#if defined(__i386__)
- return x86_32_regstr_tbl[n];
-#else
- return x86_64_regstr_tbl[n];
-#endif
-}
-
struct dwarf_regs_idx {
const char *name;
int idx;
@@ -58,7 +36,7 @@ static const struct dwarf_regs_idx x86_regidx_table[] = {
{ "rip", DWARF_REG_PC },
};

-int get_arch_regnum(const char *name)
+int get_x86_regnum(const char *name)
{
unsigned int i;

diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
index 86b3ef638fbb..eac99a246737 100644
--- a/tools/perf/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs.c
@@ -32,9 +32,17 @@
const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
unsigned int flags __maybe_unused)
{
+#if EM_HOST == EM_X86_64 || EM_HOST == EM_386
+ if (machine == EM_NONE) {
+ /* Generic arch - use host arch */
+ machine = EM_HOST;
+ }
+#endif
switch (machine) {
+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
case EM_NONE: /* Generic arch - use host arch */
return get_arch_regstr(n);
+#endif
case EM_386:
return __get_dwarf_regstr(x86_32_regstr_tbl, n);
case EM_X86_64:
@@ -65,10 +73,12 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
return NULL;
}

+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
__weak int get_arch_regnum(const char *name __maybe_unused)
{
return -ENOTSUP;
}
+#endif

/* Return DWARF register number from architecture register name */
int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags __maybe_unused)
@@ -90,9 +100,16 @@ int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags
machine = EM_HOST;
}
switch (machine) {
+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
case EM_HOST:
reg = get_arch_regnum(regname);
break;
+#endif
+ case EM_X86_64:
+ fallthrough;
+ case EM_386:
+ reg = get_x86_regnum(regname);
+ break;
default:
pr_err("ELF MACHINE %x is not supported.\n", machine);
}
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index 925525405e2d..062623aefd5a 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -79,7 +79,10 @@
#define DWARF_REG_FB 0xd3affb /* random number */

#ifdef HAVE_LIBDW_SUPPORT
+#if !defined(__x86_64__) && !defined(__i386__)
const char *get_arch_regstr(unsigned int n);
+#endif
+
/**
* get_dwarf_regstr() - Returns ftrace register string from DWARF regnum.
* @n: DWARF register number.
@@ -88,7 +91,12 @@ const char *get_arch_regstr(unsigned int n);
*/
const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags);

+int get_x86_regnum(const char *name);
+
+#if !defined(__x86_64__) && !defined(__i386__)
int get_arch_regnum(const char *name);
+#endif
+
/*
* get_dwarf_regnum - Returns DWARF regnum from register name
* name: architecture register name