commit e2dec0ff9b1e071779bee2c4e6fc82f8194b1c1d

Author: Mark Wielaard <mark@klomp.org>

Date:   Sun Jul 26 21:17:23 2020 +0200

    Handle REX prefixed JMP instruction.

    The NET Core runtime might generate a JMP with a REX prefix.

    For Jv (32bit offset) and Jb (8bit offset) this is valid.

    Prefixes that change operand size are ignored for such JMPs.

    So remove the check for sz == 4 and force sz = 4 for Jv.

    https://bugs.kde.org/show_bug.cgi?id=422174

diff --git a/VEX/priv/guest_amd64_toIR.c b/VEX/priv/guest_amd64_toIR.c

index fadf47d41..7888132eb 100644

--- a/VEX/priv/guest_amd64_toIR.c

+++ b/VEX/priv/guest_amd64_toIR.c

@@ -21392,8 +21392,8 @@ Long dis_ESC_NONE (

    case 0xE9: /* Jv (jump, 16/32 offset) */

       if (haveF3(pfx)) goto decode_failure;

-      if (sz != 4) 

-         goto decode_failure; /* JRS added 2004 July 11 */

+      sz = 4; /* Prefixes that change operand size are ignored for this

+                 instruction. Operand size is forced to 32bit. */

       if (haveF2(pfx)) DIP("bnd ; "); /* MPX bnd prefix. */

       d64 = (guest_RIP_bbstart+delta+sz) + getSDisp(sz,delta); 

       delta += sz;

@@ -21404,8 +21404,7 @@ Long dis_ESC_NONE (

    case 0xEB: /* Jb (jump, byte offset) */

       if (haveF3(pfx)) goto decode_failure;

-      if (sz != 4) 

-         goto decode_failure; /* JRS added 2004 July 11 */

+      /* Prefixes that change operand size are ignored for this instruction. */

       if (haveF2(pfx)) DIP("bnd ; "); /* MPX bnd prefix. */

       d64 = (guest_RIP_bbstart+delta+1) + getSDisp8(delta); 

       delta++;