1 files changed, 195 insertions, 0 deletions
diff --git a/libc/sanitize.c b/libc/sanitize.c
new file mode 100644
index 0000000..d4eed01
--- /dev/null
+++ b/libc/sanitize.c
@@ -0,0 +1,195 @@
+// MIT License, Copyright (c) 2021 Marvin Borner
+// Detect stack overflows and other bugs
+
+#include <def.h>
+#include <print.h>
+
+/**
+ * Stack protector
+ */
+
+#define STACK_CHK_GUARD 0xdeadbeef
+
+u32 __stack_chk_guard = STACK_CHK_GUARD;
+
+void __stack_chk_fail(void);
+void __stack_chk_fail(void)
+{
+	panic("FATAL: Stack smashing detected\n");
+}
+
+void __stack_chk_fail_local(void);
+void __stack_chk_fail_local(void)
+{
+	panic("FATAL: Local stack smashing detected\n");
+}
+
+/**
+ * UBSan
+ */
+
+#define is_aligned(value, alignment) !(value & (alignment - 1))
+
+struct source_location {
+	const char *file;
+	u32 line;
+	u32 column;
+};
+
+struct type_descriptor {
+	u16 kind;
+	u16 info;
+	char name[];
+};
+
+struct type_mismatch {
+	struct source_location location;
+	struct type_descriptor *type;
+	u32 alignment;
+	u8 type_check_kind;
+};
+
+struct overflow {
+	struct source_location location;
+	struct type_descriptor *type;
+};
+
+struct out_of_bounds {
+	struct source_location location;
+	struct type_descriptor *left_type;
+	struct type_descriptor *right_type;
+};
+
+void __ubsan_handle_load_invalid_value(void);
+void __ubsan_handle_load_invalid_value(void)
+{
+	panic("UBSAN: load-invalid-value\n");
+}
+
+void __ubsan_handle_nonnull_arg(void);
+void __ubsan_handle_nonnull_arg(void)
+{
+	panic("UBSAN: nonnull-arg\n");
+}
+
+void __ubsan_handle_nullability_arg(void);
+void __ubsan_handle_nullability_arg(void)
+{
+	panic("UBSAN: nullability-arg\n");
+}
+
+void __ubsan_handle_nonnull_return_v1(void);
+void __ubsan_handle_nonnull_return_v1(void)
+{
+	panic("UBSAN: nonnull-return-v1\n");
+}
+
+void __ubsan_handle_nullability_return_v1(void);
+void __ubsan_handle_nullability_return_v1(void)
+{
+	panic("UBSAN: nullability-return-v1\n");
+}
+
+void __ubsan_handle_vla_bound_not_positive(void);
+void __ubsan_handle_vla_bound_not_positive(void)
+{
+	panic("UBSAN: vla-bound-not-positive\n");
+}
+
+void __ubsan_handle_add_overflow(void);
+void __ubsan_handle_add_overflow(void)
+{
+	panic("UBSAN: add-overflow\n");
+}
+
+void __ubsan_handle_sub_overflow(void);
+void __ubsan_handle_sub_overflow(void)
+{
+	panic("UBSAN: sub-overflow\n");
+}
+
+void __ubsan_handle_negate_overflow(void);
+void __ubsan_handle_negate_overflow(void)
+{
+	panic("UBSAN: negate-overflow\n");
+}
+
+void __ubsan_handle_mul_overflow(void);
+void __ubsan_handle_mul_overflow(void)
+{
+	panic("UBSAN: mul-overflow\n");
+}
+
+void __ubsan_handle_shift_out_of_bounds(void);
+void __ubsan_handle_shift_out_of_bounds(void)
+{
+	panic("UBSAN: shift-out-of-bounds\n");
+}
+
+void __ubsan_handle_divrem_overflow(struct overflow *data, void *left, void *right);
+void __ubsan_handle_divrem_overflow(struct overflow *data, void *left, void *right)
+{
+	UNUSED(left);
+	UNUSED(right);
+	struct source_location *loc = &data->location;
+	panic("%s:%d: UBSAN: divrem-overflow\n", loc->file, loc->line);
+}
+
+void __ubsan_handle_out_of_bounds(struct out_of_bounds *data, void *value);
+void __ubsan_handle_out_of_bounds(struct out_of_bounds *data, void *value)
+{
+	UNUSED(value);
+	struct source_location *loc = &data->location;
+	panic("%s:%d: UBSAN: out-of-bounds\n", loc->file, loc->line);
+}
+
+void __ubsan_handle_type_mismatch_v1(struct type_mismatch *data, u32 ptr);
+void __ubsan_handle_type_mismatch_v1(struct type_mismatch *data, u32 ptr)
+{
+	struct source_location *loc = &data->location;
+	const char *msg = "";
+	if (ptr == 0) {
+		msg = "Null pointer access";
+	} else if (data->alignment != 0 && is_aligned(ptr, data->alignment))
+		msg = "Misaligned memory access";
+	else
+		msg = "Insufficient space";
+	panic("%s:%d: UBSAN: type-mismatch-v1: %s [type: %s]\n", loc->file, loc->line, msg,
+	      data->type->name);
+}
+
+void __ubsan_handle_alignment_assumption(void);
+void __ubsan_handle_alignment_assumption(void)
+{
+	panic("UBSAN: alignment-assumption\n");
+}
+
+void __ubsan_handle_builtin_unreachable(void);
+void __ubsan_handle_builtin_unreachable(void)
+{
+	panic("UBSAN: builtin-unreachable\n");
+}
+
+void __ubsan_handle_missing_return(void);
+void __ubsan_handle_missing_return(void)
+{
+	panic("UBSAN: missing-return\n");
+}
+
+void __ubsan_handle_implicit_conversion(void);
+void __ubsan_handle_implicit_conversion(void)
+{
+	panic("UBSAN: implicit-conversion\n");
+}
+
+void __ubsan_handle_invalid_builtin(void);
+void __ubsan_handle_invalid_builtin(void)
+{
+	panic("UBSAN: invalid-builtin\n");
+}
+
+void __ubsan_handle_pointer_overflow(void);
+void __ubsan_handle_pointer_overflow(void)
+{
+	panic("UBSAN: pointer-overflow\n");
+}