6 files changed, 63 insertions, 12 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 98c4713c1b09..0ad5cc70ecbe 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -880,3 +880,15 @@ unsigned int arch_reloc_size(struct reloc *reloc)
 		return 8;
 	}
 }
+
+bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc)
+{
+	switch (reloc_type(reloc)) {
+	case R_X86_64_32:
+	case R_X86_64_32S:
+	case R_X86_64_64:
+		return true;
+	default:
+		return false;
+	}
+}
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 80239843e9f0..0f6b197cfcb0 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -87,6 +87,7 @@ static const struct option check_options[] = {
 	OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"),
 	OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),
 	OPT_BOOLEAN(0  , "cfi", &opts.cfi, "annotate kernel control flow integrity (kCFI) function preambles"),
+	OPT_BOOLEAN(0  , "noabs", &opts.noabs, "reject absolute references in allocatable sections"),
 	OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),
 
 	OPT_GROUP("Options:"),
@@ -162,6 +163,7 @@ static bool opts_valid(void)
 	    opts.hack_noinstr		||
 	    opts.ibt			||
 	    opts.mcount			||
+	    opts.noabs			||
 	    opts.noinstr		||
 	    opts.orc			||
 	    opts.retpoline		||
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index d14f20ef1db1..a72059fcbc83 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2453,16 +2453,6 @@ static bool is_profiling_func(const char *name)
 	if (!strncmp(name, "__sanitizer_cov_", 16))
 		return true;
 
-	/*
-	 * Some compilers currently do not remove __tsan_func_entry/exit nor
-	 * __tsan_atomic_signal_fence (used for barrier instrumentation) with
-	 * the __no_sanitize_thread attribute, remove them. Once the kernel's
-	 * minimum Clang version is 14.0, this can be removed.
-	 */
-	if (!strncmp(name, "__tsan_func_", 12) ||
-	    !strcmp(name, "__tsan_atomic_signal_fence"))
-		return true;
-
 	return false;
 }
 
@@ -3564,7 +3554,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 		if (func && insn_func(insn) && func != insn_func(insn)->pfunc) {
 			/* Ignore KCFI type preambles, which always fall through */
 			if (!strncmp(func->name, "__cfi_", 6) ||
-			    !strncmp(func->name, "__pfx_", 6))
+			    !strncmp(func->name, "__pfx_", 6) ||
+			    !strncmp(func->name, "__pi___cfi_", 11) ||
+			    !strncmp(func->name, "__pi___pfx_", 11))
 				return 0;
 
 			if (file->ignore_unreachables)
@@ -4644,6 +4636,47 @@ static void disas_warned_funcs(struct objtool_file *file)
 		disas_funcs(funcs);
 }
 
+__weak bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc)
+{
+	unsigned int type = reloc_type(reloc);
+	size_t sz = elf_addr_size(elf);
+
+	return (sz == 8) ? (type == R_ABS64) : (type == R_ABS32);
+}
+
+static int check_abs_references(struct objtool_file *file)
+{
+	struct section *sec;
+	struct reloc *reloc;
+	int ret = 0;
+
+	for_each_sec(file, sec) {
+		/* absolute references in non-loadable sections are fine */
+		if (!(sec->sh.sh_flags & SHF_ALLOC))
+			continue;
+
+		/* section must have an associated .rela section */
+		if (!sec->rsec)
+			continue;
+
+		/*
+		 * Special case for compiler generated metadata that is not
+		 * consumed until after boot.
+		 */
+		if (!strcmp(sec->name, "__patchable_function_entries"))
+			continue;
+
+		for_each_reloc(sec->rsec, reloc) {
+			if (arch_absolute_reloc(file->elf, reloc)) {
+				WARN("section %s has absolute relocation at offset 0x%lx",
+				     sec->name, reloc_offset(reloc));
+				ret++;
+			}
+		}
+	}
+	return ret;
+}
+
 struct insn_chunk {
 	void *addr;
 	struct insn_chunk *next;
@@ -4777,6 +4810,9 @@ int check(struct objtool_file *file)
 			goto out;
 	}
 
+	if (opts.noabs)
+		warnings += check_abs_references(file);
+
 	if (opts.orc && nr_insns) {
 		ret = orc_create(file);
 		if (ret)
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index 01ef6f415adf..be33c7b43180 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -97,6 +97,7 @@ bool arch_is_embedded_insn(struct symbol *sym);
 int arch_rewrite_retpolines(struct objtool_file *file);
 
 bool arch_pc_relative_reloc(struct reloc *reloc);
+bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc);
 
 unsigned int arch_reloc_size(struct reloc *reloc);
 unsigned long arch_jump_table_sym_offset(struct reloc *reloc, struct reloc *table);
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
index 6b08666fa69d..ab22673862e1 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -26,6 +26,7 @@ struct opts {
 	bool uaccess;
 	int prefix;
 	bool cfi;
+	bool noabs;
 
 	/* options: */
 	bool backtrace;
diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h
index 6a922d046b8e..802895fae3ca 100644
--- a/tools/objtool/noreturns.h
+++ b/tools/objtool/noreturns.h
@@ -45,7 +45,6 @@ NORETURN(rewind_stack_and_make_dead)
 NORETURN(rust_begin_unwind)
 NORETURN(rust_helper_BUG)
 NORETURN(sev_es_terminate)
-NORETURN(snp_abort)
 NORETURN(start_kernel)
 NORETURN(stop_this_cpu)
 NORETURN(usercopy_abort)