Replace codepatch nopsleds with trapsleds.

ok sf@ mlarkin@
suggested by deraadt@

diff --git a/sys/arch/amd64/amd64/codepatch.c b/sys/arch/amd64/amd64/codepatch.c
index 3237044..a5bb847 100644 (file)
--- a/sys/arch/amd64/amd64/codepatch.c
+++ b/sys/arch/amd64/amd64/codepatch.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: codepatch.c,v 1.4 2017/07/01 19:38:41 sf Exp $    */
+/*      $OpenBSD: codepatch.c,v 1.5 2017/07/10 00:59:24 mortimer Exp $    */
 /*
  * Copyright (c) 2014-2015 Stefan Fritsch <sf@sfritsch.de>
  *
@@ -36,20 +36,6 @@ CTASSERT(sizeof(struct codepatch) % 8 == 0);
 extern struct codepatch codepatch_begin;
 extern struct codepatch codepatch_end;
 
-#define NOP_LEN_MAX    9
-
-static const unsigned char nops[][NOP_LEN_MAX] = {
-       { 0x90 },
-       { 0x66, 0x90 },
-       { 0x0F, 0x1F, 0x00 },
-       { 0x0F, 0x1F, 0x40, 0x00 },
-       { 0x0F, 0x1F, 0x44, 0x00, 0x00 },
-       { 0x66, 0x0F, 0x1F, 0x44, 0x00, 0x00 },
-       { 0x0F, 0x1F, 0x80, 0x00, 0x00, 0x00, 0x00 },
-       { 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 },
-       { 0x66, 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00},
-};
-
 void
 codepatch_fill_nop(void *caddr, uint16_t len)
 {
@@ -57,11 +43,21 @@ codepatch_fill_nop(void *caddr, uint16_t len)
        uint16_t nop_len;
 
        while (len > 0) {
-               if (len <= NOP_LEN_MAX)
-                       nop_len = len;
-               else
-                       nop_len = NOP_LEN_MAX;
-               memcpy(addr, nops[nop_len-1], nop_len);
+               nop_len = len < 127 ? len : 127;
+               switch (nop_len) {
+               case 1:
+                       addr[0] = 0x90;
+                       break;
+               case 2:
+                       addr[0] = 0x66;
+                       addr[1] = 0x90;
+                       break;
+               default:
+                       addr[0] = 0xEB;
+                       addr[1] = nop_len - 2;
+                       memset(addr + 2, 0xCC, nop_len - 2);
+                       break;
+               }
                addr += nop_len;
                len -= nop_len;
        }

diff --git a/sys/arch/i386/i386/codepatch.c b/sys/arch/i386/i386/codepatch.c
index 42c1889..cd44bc3 100644 (file)
--- a/sys/arch/i386/i386/codepatch.c
+++ b/sys/arch/i386/i386/codepatch.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: codepatch.c,v 1.3 2017/07/01 19:42:59 sf Exp $    */
+/*      $OpenBSD: codepatch.c,v 1.4 2017/07/10 00:59:24 mortimer Exp $    */
 /*
  * Copyright (c) 2014-2015 Stefan Fritsch <sf@sfritsch.de>
  *
@@ -35,20 +35,6 @@ struct codepatch {
 extern struct codepatch codepatch_begin;
 extern struct codepatch codepatch_end;
 
-#define NOP_LEN_MAX    9
-
-static const unsigned char nops[][NOP_LEN_MAX] = {
-       { 0x90 },
-       { 0x66, 0x90 },
-       { 0x0F, 0x1F, 0x00 },
-       { 0x0F, 0x1F, 0x40, 0x00 },
-       { 0x0F, 0x1F, 0x44, 0x00, 0x00 },
-       { 0x66, 0x0F, 0x1F, 0x44, 0x00, 0x00 },
-       { 0x0F, 0x1F, 0x80, 0x00, 0x00, 0x00, 0x00 },
-       { 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 },
-       { 0x66, 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00},
-};
-
 void
 codepatch_fill_nop(void *caddr, uint16_t len)
 {
@@ -78,11 +64,21 @@ codepatch_fill_nop(void *caddr, uint16_t len)
        }
 
        while (len > 0) {
-               if (len <= NOP_LEN_MAX)
-                       nop_len = len;
-               else
-                       nop_len = NOP_LEN_MAX;
-               memcpy(addr, nops[nop_len-1], nop_len);
+               nop_len = len < 127 ? len : 127;
+               switch (nop_len) {
+               case 1:
+                       addr[0] = 0x90;
+                       break;
+               case 2:
+                       addr[0] = 0x66;
+                       addr[1] = 0x90;
+                       break;
+               default:
+                       addr[0] = 0xEB;
+                       addr[1] = nop_len - 2;
+                       memset(addr + 2, 0xCC, nop_len - 2);
+                       break;
+               }
                addr += nop_len;
                len -= nop_len;
        }