perf dwarf-regs: Pass accurate disassembly machine to get_dwarf_regnum

Rather than pass 0/EM_NONE, use the value computed in the disasm
struct arch. Switch the EM_NONE case to EM_HOST, rewriting EM_NONE if
it were passed to get_dwarf_regnum. Pass a flags value as
architectures like csky need the flags to determine the ABI variant.

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Yang Jihong <yangjihong@bytedance.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Shenlin Liang <liangshenlin@eswincomputing.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Guilherme Amadio <amadio@gentoo.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Chen Pei <cp0613@linux.alibaba.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Aditya Gupta <adityag@linux.ibm.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Atish Patra <atishp@rivosinc.com>
Cc: Dima Kogan <dima@secretsauce.net>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: linux-csky@vger.kernel.org
Link: https://lore.kernel.org/r/20241108234606.429459-6-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Author: captain5050

tools/perf/util/annotate.c

@@ -2292,7 +2292,7 @@ static int extract_reg_offset(struct arch *arch, const char *str,
 	if (regname == NULL)
 		return -1;
 
-	op_loc->reg1 = get_dwarf_regnum(regname, 0);
+	op_loc->reg1 = get_dwarf_regnum(regname, arch->e_machine, arch->e_flags);
 	free(regname);
 
 	/* Get the second register */
@@ -2305,7 +2305,7 @@ static int extract_reg_offset(struct arch *arch, const char *str,
 		if (regname == NULL)
 			return -1;
 
-		op_loc->reg2 = get_dwarf_regnum(regname, 0);
+		op_loc->reg2 = get_dwarf_regnum(regname, arch->e_machine, arch->e_flags);
 		free(regname);
 	}
 	return 0;
@@ -2405,7 +2405,7 @@ int annotate_get_insn_location(struct arch *arch, struct disasm_line *dl,
 				return -1;
 
 			if (*s == arch->objdump.register_char)
-				op_loc->reg1 = get_dwarf_regnum(s, 0);
+				op_loc->reg1 = get_dwarf_regnum(s, arch->e_machine, arch->e_flags);
 			else if (*s == arch->objdump.imm_char) {
 				op_loc->offset = strtol(s + 1, &p, 0);
 				if (p && p != s + 1)

tools/perf/util/dwarf-regs.c

@@ -70,7 +70,7 @@ __weak int get_arch_regnum(const char *name __maybe_unused)
 }
 
 /* Return DWARF register number from architecture register name */
-int get_dwarf_regnum(const char *name, unsigned int machine)
+int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags __maybe_unused)
 {
 	char *regname = strdup(name);
 	int reg = -1;
@@ -84,8 +84,12 @@ int get_dwarf_regnum(const char *name, unsigned int machine)
 	if (p)
 		*p = '\0';
 
+	if (machine == EM_NONE) {
+		/* Generic arch - use host arch */
+		machine = EM_HOST;
+	}
 	switch (machine) {
-	case EM_NONE:	/* Generic arch - use host arch */
+	case EM_HOST:
 		reg = get_arch_regnum(regname);
 		break;
 	default:

tools/perf/util/include/dwarf-regs.h

@@ -103,12 +103,13 @@ int get_arch_regnum(const char *name);
  * name: architecture register name
  * machine: ELF machine signature (EM_*)
  */
-int get_dwarf_regnum(const char *name, unsigned int machine);
+int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags);
 
 #else /* HAVE_LIBDW_SUPPORT */
 
 static inline int get_dwarf_regnum(const char *name __maybe_unused,
-				   unsigned int machine __maybe_unused)
+				   unsigned int machine __maybe_unused,
+				   unsigned int flags __maybe_unused)
 {
 	return -1;
 }