bnd: Drop bnd prefix for relaxed short jmp instructions

Reverted the redundant branch instruction patterns for bnd prefix.
And when a relaxed jmp instruction becomes a short (Jb) form,
bnd prefix is not needed because it does not initialize bnd registers.
So in that case, bnd prefix is silently dropped.

BND JMP foo       -> drops bnd prefix
BND JMP short foo -> shows an explicit error

Signed-off-by: Jin Kyu Song <jin.kyu.song@intel.com>

diff --git a/assemble.c b/assemble.c
index a09b964..0667ef7 100644 (file)
--- a/assemble.c
+++ b/assemble.c
@@ -361,6 +361,7 @@ static bool jmp_match(int32_t segment, int64_t offset, int bits,
     int64_t isize;
     const uint8_t *code = temp->code;
     uint8_t c = code[0];
+    bool is_byte;
 
     if (((c & ~1) != 0370) || (ins->oprs[0].type & STRICT))
         return false;
@@ -379,7 +380,14 @@ static bool jmp_match(int32_t segment, int64_t offset, int bits,
         return false;
 
     isize = ins->oprs[0].offset - offset - isize; /* isize is delta */
-    return (isize >= -128 && isize <= 127); /* is it byte size? */
+    is_byte = (isize >= -128 && isize <= 127); /* is it byte size? */
+
+    if (is_byte && c == 0371 && ins->prefixes[PPS_REP] == P_BND) {
+        /* jmp short (opcode eb) cannot be used with bnd prefix. */
+        ins->prefixes[PPS_REP] = P_none;
+    }
+
+    return is_byte;
 }
 
 int64_t assemble(int32_t segment, int64_t offset, int bits, iflags_t cp,
@@ -684,6 +692,9 @@ int64_t assemble(int32_t segment, int64_t offset, int bits, iflags_t cp,
             error(ERR_NONFATAL, "instruction not supported in %d-bit mode",
                   bits);
             break;
+        case MERR_BADBND:
+            error(ERR_NONFATAL, "bnd prefix is not allowed");
+            break;
         default:
             error(ERR_NONFATAL,
                   "invalid combination of opcode and operands");

diff --git a/insns.dat b/insns.dat
index edf7db8..5464f93 100644 (file)
--- a/insns.dat
+++ b/insns.dat
@@ -245,18 +245,18 @@ BTS               reg64,reg64                     [mr:    o64 0f ab /r]                           X64
 BTS            rm16,imm                        [mi:    hle o16 0f ba /5 ib,u]                  386,SB,LOCK
 BTS            rm32,imm                        [mi:    hle o32 0f ba /5 ib,u]                  386,SB,LOCK
 BTS            rm64,imm                        [mi:    hle o64 0f ba /5 ib,u]                  X64,SB,LOCK
-CALL           imm                             [i:     odf e8 rel]                             8086
-CALL           imm|near                        [i:     odf e8 rel]                             8086,ND
+CALL           imm                             [i:     odf e8 rel]                             8086,BND
+CALL           imm|near                        [i:     odf e8 rel]                             8086,ND,BND
 CALL           imm|far                         [i:     odf 9a iwd seg]                         8086,ND,NOLONG
 ; Call/jmp near imm/reg/mem is always 64-bit in long mode.
-CALL           imm16                           [i:     o16 e8 rel]                             8086,NOLONG
-CALL           imm16|near                      [i:     o16 e8 rel]                             8086,ND,NOLONG
+CALL           imm16                           [i:     o16 e8 rel]                             8086,NOLONG,BND
+CALL           imm16|near                      [i:     o16 e8 rel]                             8086,ND,NOLONG,BND
 CALL           imm16|far                       [i:     o16 9a iwd seg]                         8086,ND,NOLONG
-CALL           imm32                           [i:     o32 e8 rel]                             386,NOLONG
-CALL           imm32|near                      [i:     o32 e8 rel]                             386,ND,NOLONG
+CALL           imm32                           [i:     o32 e8 rel]                             386,NOLONG,BND
+CALL           imm32|near                      [i:     o32 e8 rel]                             386,ND,NOLONG,BND
 CALL           imm32|far                       [i:     o32 9a iwd seg]                         386,ND,NOLONG
-CALL           imm64                           [i:     o64nw e8 rel]                           X64
-CALL           imm64|near                      [i:     o64nw e8 rel]                           X64,ND
+CALL           imm64                           [i:     o64nw e8 rel]                           X64,BND
+CALL           imm64|near                      [i:     o64nw e8 rel]                           X64,ND,BND
 CALL           imm:imm                         [ji:    odf 9a iwd iw]                          8086,NOLONG
 CALL           imm16:imm                       [ji:    o16 9a iw iw]                           8086,NOLONG
 CALL           imm:imm16                       [ji:    o16 9a iw iw]                           8086,NOLONG
@@ -267,31 +267,14 @@ CALL              mem|far                         [m:     o64 ff /3]                              X64
 CALL           mem16|far                       [m:     o16 ff /3]                              8086
 CALL           mem32|far                       [m:     o32 ff /3]                              386
 CALL           mem64|far                       [m:     o64 ff /3]                              X64
-CALL           mem|near                        [m:     odf ff /2]                              8086,ND
-CALL           rm16|near                       [m:     o16 ff /2]                              8086,NOLONG,ND
-CALL           rm32|near                       [m:     o32 ff /2]                              386,NOLONG,ND
-CALL           rm64|near                       [m:     o64nw ff /2]                            X64,ND
-CALL           mem                             [m:     odf ff /2]                              8086
-CALL           rm16                            [m:     o16 ff /2]                              8086,NOLONG
-CALL           rm32                            [m:     o32 ff /2]                              386,NOLONG
-CALL           rm64                            [m:     o64nw ff /2]                            X64
-; BND + CALL
-CALL           imm                             [i:     odf e8 rel]                             8086,MPX,BND
-CALL           imm|near                        [i:     odf e8 rel]                             8086,ND,MPX,BND
-CALL           imm16                           [i:     o16 e8 rel]                             8086,NOLONG,MPX,BND
-CALL           imm16|near                      [i:     o16 e8 rel]                             8086,ND,NOLONG,MPX,BND
-CALL           imm32                           [i:     o32 e8 rel]                             386,NOLONG,MPX,BND
-CALL           imm32|near                      [i:     o32 e8 rel]                             386,ND,NOLONG,MPX,BND
-CALL           imm64                           [i:     o64nw e8 rel]                           X64,MPX,BND
-CALL           imm64|near                      [i:     o64nw e8 rel]                           X64,ND,MPX,BND
-CALL           mem|near                        [m:     odf ff /2]                              8086,ND,MPX,BND
-CALL           rm16|near                       [m:     o16 ff /2]                              8086,NOLONG,ND,MPX,BND
-CALL           rm32|near                       [m:     o32 ff /2]                              386,NOLONG,ND,MPX,BND
-CALL           rm64|near                       [m:     o64nw ff /2]                            X64,ND,MPX,BND
-CALL           mem                             [m:     odf ff /2]                              8086,MPX,BND
-CALL           rm16                            [m:     o16 ff /2]                              8086,NOLONG,MPX,BND
-CALL           rm32                            [m:     o32 ff /2]                              386,NOLONG,MPX,BND
-CALL           rm64                            [m:     o64nw ff /2]                            X64,MPX,BND
+CALL           mem|near                        [m:     odf ff /2]                              8086,ND,BND
+CALL           rm16|near                       [m:     o16 ff /2]                              8086,NOLONG,ND,BND
+CALL           rm32|near                       [m:     o32 ff /2]                              386,NOLONG,ND,BND
+CALL           rm64|near                       [m:     o64nw ff /2]                            X64,ND,BND
+CALL           mem                             [m:     odf ff /2]                              8086,BND
+CALL           rm16                            [m:     o16 ff /2]                              8086,NOLONG,BND
+CALL           rm32                            [m:     o32 ff /2]                              386,NOLONG,BND
+CALL           rm64                            [m:     o64nw ff /2]                            X64,BND
 
 CBW            void                            [       o16 98]                                 8086
 CDQ            void                            [       o32 99]                                 386
@@ -696,18 +679,18 @@ JECXZ             imm                             [i:     a32 e3 rel8]                            386
 JRCXZ          imm                             [i:     a64 e3 rel8]                            X64
 JMP            imm|short                       [i:     eb rel8]                                8086
 JMP            imm                             [i:     jmp8 eb rel8]                           8086,ND
-JMP            imm                             [i:     odf e9 rel]                             8086
-JMP            imm|near                        [i:     odf e9 rel]                             8086,ND
+JMP            imm                             [i:     odf e9 rel]                             8086,BND
+JMP            imm|near                        [i:     odf e9 rel]                             8086,ND,BND
 JMP            imm|far                         [i:     odf ea iwd seg]                         8086,ND,NOLONG
 ; Call/jmp near imm/reg/mem is always 64-bit in long mode.
-JMP            imm16                           [i:     o16 e9 rel]                             8086,NOLONG
-JMP            imm16|near                      [i:     o16 e9 rel]                             8086,ND,NOLONG
+JMP            imm16                           [i:     o16 e9 rel]                             8086,NOLONG,BND
+JMP            imm16|near                      [i:     o16 e9 rel]                             8086,ND,NOLONG,BND
 JMP            imm16|far                       [i:     o16 ea iwd seg]                         8086,ND,NOLONG
-JMP            imm32                           [i:     o32 e9 rel]                             386,NOLONG
-JMP            imm32|near                      [i:     o32 e9 rel]                             386,ND,NOLONG
+JMP            imm32                           [i:     o32 e9 rel]                             386,NOLONG,BND
+JMP            imm32|near                      [i:     o32 e9 rel]                             386,ND,NOLONG,BND
 JMP            imm32|far                       [i:     o32 ea iwd seg]                         386,ND,NOLONG
-JMP            imm64                           [i:     o64nw e9 rel]                           X64
-JMP            imm64|near                      [i:     o64nw e9 rel]                           X64,ND
+JMP            imm64                           [i:     o64nw e9 rel]                           X64,BND
+JMP            imm64|near                      [i:     o64nw e9 rel]                           X64,ND,BND
 JMP            imm:imm                         [ji:    odf ea iwd iw]                          8086,NOLONG
 JMP            imm16:imm                       [ji:    o16 ea iw iw]                           8086,NOLONG
 JMP            imm:imm16                       [ji:    o16 ea iw iw]                           8086,NOLONG
@@ -718,31 +701,14 @@ JMP               mem|far                         [m:     o64 ff /5]                              X64
 JMP            mem16|far                       [m:     o16 ff /5]                              8086
 JMP            mem32|far                       [m:     o32 ff /5]                              386
 JMP            mem64|far                       [m:     o64 ff /5]                              X64
-JMP            mem|near                        [m:     odf ff /4]                              8086,ND
-JMP            rm16|near                       [m:     o16 ff /4]                              8086,NOLONG,ND
-JMP            rm32|near                       [m:     o32 ff /4]                              386,NOLONG,ND
-JMP            rm64|near                       [m:     o64nw ff /4]                            X64,ND
-JMP            mem                             [m:     odf ff /4]                              8086
-JMP            rm16                            [m:     o16 ff /4]                              8086,NOLONG
-JMP            rm32                            [m:     o32 ff /4]                              386,NOLONG
-JMP            rm64                            [m:     o64nw ff /4]                            X64
-; BND + JMP
-JMP            imm                             [i:     odf e9 rel]                             8086,MPX,BND
-JMP            imm|near                        [i:     odf e9 rel]                             8086,ND,MPX,BND
-JMP            imm16                           [i:     o16 e9 rel]                             8086,NOLONG,MPX,BND
-JMP            imm16|near                      [i:     o16 e9 rel]                             8086,ND,NOLONG,MPX,BND
-JMP            imm32                           [i:     o32 e9 rel]                             386,NOLONG,MPX,BND
-JMP            imm32|near                      [i:     o32 e9 rel]                             386,ND,NOLONG,MPX,BND
-JMP            imm64                           [i:     o64nw e9 rel]                           X64,MPX,BND
-JMP            imm64|near                      [i:     o64nw e9 rel]                           X64,ND,MPX,BND
-JMP            mem|near                        [m:     odf ff /4]                              8086,ND,MPX,BND
-JMP            rm16|near                       [m:     o16 ff /4]                              8086,NOLONG,ND,MPX,BND
-JMP            rm32|near                       [m:     o32 ff /4]                              386,NOLONG,ND,MPX,BND
-JMP            rm64|near                       [m:     o64nw ff /4]                            X64,ND,MPX,BND
-JMP            mem                             [m:     odf ff /4]                              8086,MPX,BND
-JMP            rm16                            [m:     o16 ff /4]                              8086,NOLONG,MPX,BND
-JMP            rm32                            [m:     o32 ff /4]                              386,NOLONG,MPX,BND
-JMP            rm64                            [m:     o64nw ff /4]                            X64,MPX,BND
+JMP            mem|near                        [m:     odf ff /4]                              8086,ND,BND
+JMP            rm16|near                       [m:     o16 ff /4]                              8086,NOLONG,ND,BND
+JMP            rm32|near                       [m:     o32 ff /4]                              386,NOLONG,ND,BND
+JMP            rm64|near                       [m:     o64nw ff /4]                            X64,ND,BND
+JMP            mem                             [m:     odf ff /4]                              8086,BND
+JMP            rm16                            [m:     o16 ff /4]                              8086,NOLONG,BND
+JMP            rm32                            [m:     o32 ff /4]                              386,NOLONG,BND
+JMP            rm64                            [m:     o64nw ff /4]                            X64,BND
 
 JMPE           imm                             [i:     odf 0f b8 rel]                          IA64
 JMPE           imm16                           [i:     o16 0f b8 rel]                          IA64
@@ -1149,17 +1115,12 @@ RDMSR           void                            [       0f 32]                                  PENT,PRIV
 RDPMC          void                            [       0f 33]                                  P6
 RDTSC          void                            [       0f 31]                                  PENT
 RDTSCP         void                            [       0f 01 f9]                               X86_64
-RET            void                            [       c3]                                     8086
-RET            imm                             [i:     c2 iw]                                  8086,SW
+RET            void                            [       c3]                                     8086,BND
+RET            imm                             [i:     c2 iw]                                  8086,SW,BND
 RETF           void                            [       cb]                                     8086
 RETF           imm                             [i:     ca iw]                                  8086,SW
-RETN           void                            [       c3]                                     8086
-RETN           imm                             [i:     c2 iw]                                  8086,SW
-; BND + RET
-RET            void                            [       c3]                                     8086,MPX,BND
-RET            imm                             [i:     c2 iw]                                  8086,SW,MPX,BND
-RETN           void                            [       c3]                                     8086,MPX,BND
-RETN           imm                             [i:     c2 iw]                                  8086,SW,MPX,BND
+RETN           void                            [       c3]                                     8086,BND
+RETN           imm                             [i:     c2 iw]                                  8086,SW,BND
 
 ROL            rm8,unity                       [m-:    d0 /0]                                  8086
 ROL            rm8,reg_cl                      [m-:    d2 /0]                                  8086
@@ -1518,25 +1479,15 @@ CMOVcc          reg32,mem                       [rm:    o32 0f 40+c /r]                         P6,SM
 CMOVcc         reg32,reg32                     [rm:    o32 0f 40+c /r]                         P6
 CMOVcc         reg64,mem                       [rm:    o64 0f 40+c /r]                         X64,SM
 CMOVcc         reg64,reg64                     [rm:    o64 0f 40+c /r]                         X64
-Jcc            imm|near                        [i:     odf 0f 80+c rel]                        386
-Jcc            imm16|near                      [i:     o16 0f 80+c rel]                        386,NOLONG
-Jcc            imm32|near                      [i:     o32 0f 80+c rel]                        386,NOLONG
-Jcc            imm64|near                      [i:     o64nw 0f 80+c rel]                      X64
-Jcc            imm|short                       [i:     70+c rel8]                              8086,ND
-Jcc            imm                             [i:     jcc8 70+c rel8]                         8086,ND
-Jcc            imm                             [i:     0f 80+c rel]                            386,ND
-Jcc            imm                             [i:     71+c jlen e9 rel]                       8086,ND
-Jcc            imm                             [i:     70+c rel8]                              8086
-; BND + Jcc
-Jcc            imm|near                        [i:     odf 0f 80+c rel]                386,MPX,BND
-Jcc            imm16|near                      [i:     o16 0f 80+c rel]                386,NOLONG,MPX,BND
-Jcc            imm32|near                      [i:     o32 0f 80+c rel]                386,NOLONG,MPX,BND
-Jcc            imm64|near                      [i:     o64nw 0f 80+c rel]              X64,MPX,BND
-Jcc            imm|short                       [i:     70+c rel8]                      8086,ND,MPX,BND
-Jcc            imm                             [i:     jcc8 70+c rel8]                 8086,ND,MPX,BND
-Jcc            imm                             [i:     0f 80+c rel]                    386,ND,MPX,BND
-Jcc            imm                             [i:     71+c jlen e9 rel]               8086,ND,MPX,BND
-Jcc            imm                             [i:     70+c rel8]                      8086,MPX,BND
+Jcc            imm|near                        [i:     odf 0f 80+c rel]                        386,BND
+Jcc            imm16|near                      [i:     o16 0f 80+c rel]                        386,NOLONG,BND
+Jcc            imm32|near                      [i:     o32 0f 80+c rel]                        386,NOLONG,BND
+Jcc            imm64|near                      [i:     o64nw 0f 80+c rel]                      X64,BND
+Jcc            imm|short                       [i:     70+c rel8]                              8086,ND,BND
+Jcc            imm                             [i:     jcc8 70+c rel8]                         8086,ND,BND
+Jcc            imm                             [i:     0f 80+c rel]                            386,ND,BND
+Jcc            imm                             [i:     71+c jlen e9 rel]                       8086,ND,BND
+Jcc            imm                             [i:     70+c rel8]                              8086,BND
 
 SETcc          mem                             [m:     0f 90+c /0]                             386,SB
 SETcc          reg8                            [m:     0f 90+c /0]                             386

diff --git a/test/mpx-64.asm b/test/mpx-64.asm
index bc5e7d4..d177622 100644 (file)
--- a/test/mpx-64.asm
+++ b/test/mpx-64.asm
@@ -111,7 +111,10 @@ BITS 64
        ; bnd
        bnd ret
        bnd call      foo
-       bnd jmp       foo
+       bnd jmp       foo       ; when it becomes a Jb form - short jmp (eb),
+                               ; bnd prefix is silently dropped
+       bnd jmp       near 0    ; near jmp (opcode e9)
+;      bnd jmp       short 0   ; explicit short jmp (opcode eb) : error
        bnd jno       foo
 
 foo:   bnd ret

diff --git a/test/mpx.asm b/test/mpx.asm
index 24ffcc8..1fd5b1d 100644 (file)
--- a/test/mpx.asm
+++ b/test/mpx.asm
@@ -79,7 +79,10 @@ BITS 32
        ; bnd
        bnd ret
        bnd call      foo
-       bnd jmp       foo
+       bnd jmp       foo       ; when it becomes a Jb form - short jmp (eb),
+                               ; bnd prefix is silently dropped
+       bnd jmp       near 0    ; near jmp (opcode e9)
+;      bnd jmp       short 0   ; explicit short jmp (opcode eb) : error
        bnd jno       foo
 
 foo:   bnd ret