code review 7543043: runtime: faster & safer hash function

src/pkg/runtime/vdso_linux_amd64.c

 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "runtime.h"
 
+#define AT_RANDOM 25
 #define AT_SYSINFO_EHDR 33
 #define AT_NULL 0    /* End of vector */
 #define PT_LOAD 1    /* Loadable program segment */
 #define PT_DYNAMIC 2 /* Dynamic linking information */
 #define DT_NULL 0    /* Marks end of dynamic section */
 #define DT_STRTAB 5  /* Address of string table */
 #define DT_SYMTAB 6  /* Address of symbol table */
 #define DT_VERSYM 0x6ffffff0
 #define DT_VERDEF 0x6ffffffc
 
@@ skipping 295 matching lines @@
         // skip NULL separator
         p++;
 
         // now, p points to auxv
         Elf64_auxv_t *elf_auxv = (Elf64_auxv_t*) p;
 
         for(int32 i=0; elf_auxv[i].a_type!=AT_NULL; i++) {
                 if(elf_auxv[i].a_type == AT_SYSINFO_EHDR) {
                         if(elf_auxv[i].a_un.a_val == 0) {
                                 // Something went wrong
-                                return;
+                                continue;
                         }
                         vdso_init_from_sysinfo_ehdr(&vdso_info, (Elf64_Ehdr*)elf_auxv[i].a_un.a_val);
                         vdso_parse_symbols(&vdso_info, vdso_find_version(&vdso_info, &linux26));
-                        return;
+                        continue;
+                }
+                if(elf_auxv[i].a_type == AT_RANDOM) {
+                        runtime·startup_random_data = (byte*)elf_auxv[i].a_un.a_val;
+                        runtime·startup_random_data_len = 16;
+                        continue;
                 }
         }
 }
 
 void (*runtime·sysargs)(int32, uint8**) = runtime·linux_setup_vdso;