1 files changed, 71 insertions, 4 deletions

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 01237d167223..6604f5d038aa 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -178,6 +178,52 @@ static bool is_sibling_call(struct instruction *insn)
 }
 
 /*
+ * Checks if a string ends with another.
+ */
+static bool str_ends_with(const char *s, const char *sub)
+{
+	const int slen = strlen(s);
+	const int sublen = strlen(sub);
+
+	if (sublen > slen)
+		return 0;
+
+	return !memcmp(s + slen - sublen, sub, sublen);
+}
+
+/*
+ * Checks if a function is a Rust "noreturn" one.
+ */
+static bool is_rust_noreturn(const struct symbol *func)
+{
+	/*
+	 * If it does not start with "_R", then it is not a Rust symbol.
+	 */
+	if (strncmp(func->name, "_R", 2))
+		return false;
+
+	/*
+	 * These are just heuristics -- we do not control the precise symbol
+	 * name, due to the crate disambiguators (which depend on the compiler)
+	 * as well as changes to the source code itself between versions (since
+	 * these come from the Rust standard library).
+	 */
+	return str_ends_with(func->name, "_4core5sliceSp15copy_from_slice17len_mismatch_fail")		||
+	       str_ends_with(func->name, "_4core6option13unwrap_failed")				||
+	       str_ends_with(func->name, "_4core6result13unwrap_failed")				||
+	       str_ends_with(func->name, "_4core9panicking5panic")					||
+	       str_ends_with(func->name, "_4core9panicking9panic_fmt")					||
+	       str_ends_with(func->name, "_4core9panicking14panic_explicit")				||
+	       str_ends_with(func->name, "_4core9panicking14panic_nounwind")				||
+	       str_ends_with(func->name, "_4core9panicking18panic_bounds_check")			||
+	       str_ends_with(func->name, "_4core9panicking19assert_failed_inner")			||
+	       str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference")	||
+	       strstr(func->name, "_4core9panicking11panic_const24panic_const_")			||
+	       (strstr(func->name, "_4core5slice5index24slice_") &&
+		str_ends_with(func->name, "_fail"));
+}
+
+/*
  * This checks to see if the given function is a "noreturn" function.
  *
  * For global functions which are outside the scope of this object file, we
@@ -202,10 +248,14 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 	if (!func)
 		return false;
 
-	if (func->bind == STB_GLOBAL || func->bind == STB_WEAK)
+	if (func->bind == STB_GLOBAL || func->bind == STB_WEAK) {
+		if (is_rust_noreturn(func))
+			return true;
+
 		for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
 			if (!strcmp(func->name, global_noreturns[i]))
 				return true;
+	}
 
 	if (func->bind == STB_WEAK)
 		return false;
@@ -2993,10 +3043,27 @@ static int update_cfi_state(struct instruction *insn,
 				break;
 			}
 
-			if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) {
+			if (op->dest.reg == CFI_BP && op->src.reg == CFI_SP &&
+			    insn->sym->frame_pointer) {
+				/* addi.d fp,sp,imm on LoongArch */
+				if (cfa->base == CFI_SP && cfa->offset == op->src.offset) {
+					cfa->base = CFI_BP;
+					cfa->offset = 0;
+				}
+				break;
+			}
 
-				/* lea disp(%rbp), %rsp */
-				cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset);
+			if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) {
+				/* addi.d sp,fp,imm on LoongArch */
+				if (cfa->base == CFI_BP && cfa->offset == 0) {
+					if (insn->sym->frame_pointer) {
+						cfa->base = CFI_SP;
+						cfa->offset = -op->src.offset;
+					}
+				} else {
+					/* lea disp(%rbp), %rsp */
+					cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset);
+				}
 				break;
 			}