From 26a453fb5637907a538d6ea5ef23651142811e15 Mon Sep 17 00:00:00 2001
From: Alexandre Chartre <alexandre.chartre@oracle.com>
Date: Fri, 21 Nov 2025 10:53:22 +0100
Subject: objtool: Improve register reporting during function validation

When tracing function validation, instruction state changes can
report changes involving registers. These registers are reported
with the name "r<num>" (e.g. "r3"). Print the CPU specific register
name instead of a generic name (e.g. print "rbx" instead of "r3"
on x86).

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-13-alexandre.chartre@oracle.com
---
 tools/objtool/arch/loongarch/decode.c | 11 +++++++++++
 tools/objtool/arch/powerpc/decode.c   | 12 ++++++++++++
 tools/objtool/arch/x86/decode.c       |  8 ++++++++
 3 files changed, 31 insertions(+)

(limited to 'tools/objtool/arch')

diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
index 1de86ebb637d..6cd288150f49 100644
--- a/tools/objtool/arch/loongarch/decode.c
+++ b/tools/objtool/arch/loongarch/decode.c
@@ -8,6 +8,17 @@
 #include <linux/objtool_types.h>
 #include <arch/elf.h>
 
+const char *arch_reg_name[CFI_NUM_REGS] = {
+	"zero", "ra", "tp", "sp",
+	"a0", "a1", "a2", "a3",
+	"a4", "a5", "a6", "a7",
+	"t0", "t1", "t2", "t3",
+	"t4", "t5", "t6", "t7",
+	"t8", "u0", "fp", "s0",
+	"s1", "s2", "s3", "s4",
+	"s5", "s6", "s7", "s8"
+};
+
 int arch_ftrace_match(const char *name)
 {
 	return !strcmp(name, "_mcount");
diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
index 4f68b402e785..e534ac1123b3 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -9,6 +9,18 @@
 #include <objtool/warn.h>
 #include <objtool/builtin.h>
 
+const char *arch_reg_name[CFI_NUM_REGS] = {
+	"r0",  "sp",  "r2",  "r3",
+	"r4",  "r5",  "r6",  "r7",
+	"r8",  "r9",  "r10", "r11",
+	"r12", "r13", "r14", "r15",
+	"r16", "r17", "r18", "r19",
+	"r20", "r21", "r22", "r23",
+	"r24", "r25", "r26", "r27",
+	"r28", "r29", "r30", "r31",
+	"ra"
+};
+
 int arch_ftrace_match(const char *name)
 {
 	return !strcmp(name, "_mcount");
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 83e9c604ce10..f4af82508228 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -23,6 +23,14 @@
 #include <objtool/builtin.h>
 #include <arch/elf.h>
 
+const char *arch_reg_name[CFI_NUM_REGS] = {
+	"rax", "rcx", "rdx", "rbx",
+	"rsp", "rbp", "rsi", "rdi",
+	"r8",  "r9",  "r10", "r11",
+	"r12", "r13", "r14", "r15",
+	"ra"
+};
+
 int arch_ftrace_match(const char *name)
 {
 	return !strcmp(name, "__fentry__");
-- 
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