fundamental: Add overflow-safe math helpers

ADD_SAFE/SUB_SAFE/MUL_SAFE do addition/subtraction/multiplication respectively with an overflow check. If an overflow occurs these return false, otherwise true. Example: (c = a + b) would become ADD_SAFE(&c, a, b) INC_SAFE/DEC_SAFE/MUL_ASSIGN_SAFE are like above but they also reassign the first argument. Example: (a += b) would become INC_SAFE(&a, b)
2024-02-13 13:08:20 -05:00
parent 6d55e3a364
commit a7a67dfd9d
6 changed files with 179 additions and 8 deletions
@@ -540,7 +540,7 @@ static int module_callback(Dwfl_Module *mod, void **userdata, const char *name,
                        continue;

                /* Check that the end of segment is a valid address. */
-                if (__builtin_add_overflow(program_header->p_vaddr, program_header->p_memsz, &end_of_segment)) {
+                if (!ADD_SAFE(&end_of_segment, program_header->p_vaddr, program_header->p_memsz)) {
                        log_error("Abort due to corrupted core dump, end of segment address %#zx + %#zx overflows", (size_t)program_header->p_vaddr, (size_t)program_header->p_memsz);
                        return DWARF_CB_ABORT;
                }