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From: Kees Cook <keescook@chromium.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Youling Tang <tangyouling@loongson.cn>,
	Jinyang He <hejinyang@loongson.cn>,
	Huacai Chen <chenhuacai@kernel.org>,
	Tiezhu Yang <yangtiezhu@loongson.cn>,
	linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: [PATCH] objtool: Provide origin hint for elf_init_reloc_text_sym() errors
Date: Tue, 30 Apr 2024 16:51:07 -0700
Message-Id: <20240430235106.work.680-kees@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

An error report from elf_init_reloc_text_sym() doesn't say what list of
symbols it is working on. Include this on the caller's side so it can be
reported when pathological conditions are encountered.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
I added this to confirm debugging of
https://lore.kernel.org/lkml/202308301532.d7acf63e-oliver.sang@intel.com/
---
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Youling Tang <tangyouling@loongson.cn>
Cc: Jinyang He <hejinyang@loongson.cn>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 tools/objtool/arch/loongarch/orc.c  |  3 ++-
 tools/objtool/arch/x86/orc.c        |  3 ++-
 tools/objtool/check.c               | 21 +++++++++++++--------
 tools/objtool/elf.c                 |  7 ++++---
 tools/objtool/include/objtool/elf.h |  3 ++-
 5 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/tools/objtool/arch/loongarch/orc.c b/tools/objtool/arch/loongarch/orc.c
index 873536d009d9..5ed9c1bb2de3 100644
--- a/tools/objtool/arch/loongarch/orc.c
+++ b/tools/objtool/arch/loongarch/orc.c
@@ -110,7 +110,8 @@ int write_orc_entry(struct elf *elf, struct section *orc_sec,
 	memcpy(orc, o, sizeof(*orc));
 
 	/* populate reloc for ip */
-	if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx,
+	if (!elf_init_reloc_text_sym("orc_list", elf, ip_sec,
+				     idx * sizeof(int), idx,
 				     insn_sec, insn_off))
 		return -1;
 
diff --git a/tools/objtool/arch/x86/orc.c b/tools/objtool/arch/x86/orc.c
index b6cd943e87f9..68a78ad0d99e 100644
--- a/tools/objtool/arch/x86/orc.c
+++ b/tools/objtool/arch/x86/orc.c
@@ -111,7 +111,8 @@ int write_orc_entry(struct elf *elf, struct section *orc_sec,
 	orc->bp_offset = bswap_if_needed(elf, orc->bp_offset);
 
 	/* populate reloc for ip */
-	if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx,
+	if (!elf_init_reloc_text_sym("orc_list", elf, ip_sec,
+				     idx * sizeof(int), idx,
 				     insn_sec, insn_off))
 		return -1;
 
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 0a33d9195b7a..e7f7300ba88b 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -701,7 +701,7 @@ static int create_static_call_sections(struct objtool_file *file)
 	list_for_each_entry(insn, &file->static_call_list, call_node) {
 
 		/* populate reloc for 'addr' */
-		if (!elf_init_reloc_text_sym(file->elf, sec,
+		if (!elf_init_reloc_text_sym("static_call_list", file->elf, sec,
 					     idx * sizeof(*site), idx * 2,
 					     insn->sec, insn->offset))
 			return -1;
@@ -782,7 +782,8 @@ static int create_retpoline_sites_sections(struct objtool_file *file)
 	idx = 0;
 	list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
 
-		if (!elf_init_reloc_text_sym(file->elf, sec,
+		if (!elf_init_reloc_text_sym("retpoline_call_list",
+					     file->elf, sec,
 					     idx * sizeof(int), idx,
 					     insn->sec, insn->offset))
 			return -1;
@@ -820,7 +821,8 @@ static int create_return_sites_sections(struct objtool_file *file)
 	idx = 0;
 	list_for_each_entry(insn, &file->return_thunk_list, call_node) {
 
-		if (!elf_init_reloc_text_sym(file->elf, sec,
+		if (!elf_init_reloc_text_sym("return_thunk_list",
+					     file->elf, sec,
 					     idx * sizeof(int), idx,
 					     insn->sec, insn->offset))
 			return -1;
@@ -874,7 +876,8 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)
 		     !strcmp(sym->name, "cleanup_module")))
 			WARN("%s(): not an indirect call target", sym->name);
 
-		if (!elf_init_reloc_text_sym(file->elf, sec,
+		if (!elf_init_reloc_text_sym("endbr_list",
+					     file->elf, sec,
 					     idx * sizeof(int), idx,
 					     insn->sec, insn->offset))
 			return -1;
@@ -922,7 +925,7 @@ static int create_cfi_sections(struct objtool_file *file)
 		if (strncmp(sym->name, "__cfi_", 6))
 			continue;
 
-		if (!elf_init_reloc_text_sym(file->elf, sec,
+		if (!elf_init_reloc_text_sym(".cfi_sites", file->elf, sec,
 					     idx * sizeof(unsigned int), idx,
 					     sym->sec, sym->offset))
 			return -1;
@@ -966,8 +969,10 @@ static int create_mcount_loc_sections(struct objtool_file *file)
 
 		struct reloc *reloc;
 
-		reloc = elf_init_reloc_text_sym(file->elf, sec, idx * addr_size, idx,
-					       insn->sec, insn->offset);
+		reloc = elf_init_reloc_text_sym("mcount_loc_list",
+						file->elf, sec,
+						idx * addr_size, idx,
+						insn->sec, insn->offset);
 		if (!reloc)
 			return -1;
 
@@ -1007,7 +1012,7 @@ static int create_direct_call_sections(struct objtool_file *file)
 	idx = 0;
 	list_for_each_entry(insn, &file->call_list, call_node) {
 
-		if (!elf_init_reloc_text_sym(file->elf, sec,
+		if (!elf_init_reloc_text_sym("call_list", file->elf, sec,
 					     idx * sizeof(unsigned int), idx,
 					     insn->sec, insn->offset))
 			return -1;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 3d27983dc908..8615672e2ff9 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -881,7 +881,8 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec,
 	return reloc;
 }
 
-struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec,
+struct reloc *elf_init_reloc_text_sym(const char *origin,
+				      struct elf *elf, struct section *sec,
 				      unsigned long offset,
 				      unsigned int reloc_idx,
 				      struct section *insn_sec,
@@ -891,8 +892,8 @@ struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec,
 	int addend = insn_off;
 
 	if (!(insn_sec->sh.sh_flags & SHF_EXECINSTR)) {
-		WARN("bad call to %s() for data symbol %s",
-		     __func__, sym->name);
+		WARN("bad call to %s() for %s symbol %s",
+		     __func__, origin, sym->name);
 		return NULL;
 	}
 
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index 2b8a69de4db8..d026e707806d 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -115,7 +115,8 @@ struct section *elf_create_section_pair(struct elf *elf, const char *name,
 
 struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size);
 
-struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec,
+struct reloc *elf_init_reloc_text_sym(const char *origin,
+				      struct elf *elf, struct section *sec,
 				      unsigned long offset,
 				      unsigned int reloc_idx,
 				      struct section *insn_sec,
-- 
2.34.1