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-rw-r--r--tools/objtool/check.c52
1 files changed, 51 insertions, 1 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 01237d167223..d086f207a3d3 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;