diff options
| -rw-r--r-- | lib/x86/arch-transform-dis.inc.h | 2 | ||||
| -rw-r--r-- | lib/x86/jump-patch.h | 2 | ||||
| -rwxr-xr-x | script/test-transform-dis.sh | 6 | ||||
| -rw-r--r-- | test/transform-dis-cases-i386.S | 10 |
4 files changed, 14 insertions, 6 deletions
diff --git a/lib/x86/arch-transform-dis.inc.h b/lib/x86/arch-transform-dis.inc.h index 6ec6c16..67390c9 100644 --- a/lib/x86/arch-transform-dis.inc.h +++ b/lib/x86/arch-transform-dis.inc.h @@ -76,7 +76,7 @@ static void transform_dis_branch(struct transform_dis_ctx *ctx, uint_tptr dpc, code += ctx->base.op_size; struct arch_dis_ctx arch; - uintptr_t source = ctx->pc_trampoline + 2; + uintptr_t source = ctx->pc_trampoline + ctx->base.op_size + 2; int size = jump_patch_size(source, dpc, arch, true); /* If not taken, jmp past the big jump - this is a bit suboptimal but not * that bad. diff --git a/lib/x86/jump-patch.h b/lib/x86/jump-patch.h index 8cd7d6f..ca7b16c 100644 --- a/lib/x86/jump-patch.h +++ b/lib/x86/jump-patch.h @@ -15,7 +15,7 @@ static inline int jump_patch_size(uint_tptr pc, uint_tptr dpc, static inline void make_jump_patch(void **codep, uint_tptr pc, uint_tptr dpc, UNUSED struct arch_dis_ctx arch) { - uint_tptr diff = pc - (dpc + 5); + uint_tptr diff = dpc - (pc + 5); void *code = *codep; if (diff == (uint_tptr) (int32_t) diff) { op8(&code, 0xe9); diff --git a/script/test-transform-dis.sh b/script/test-transform-dis.sh new file mode 100755 index 0000000..556746b --- /dev/null +++ b/script/test-transform-dis.sh @@ -0,0 +1,6 @@ +#!/bin/sh +set -xe +make out/transform-dis-cases-$1.bin out/test-transform-dis-$1 +out/test-transform-dis-$1 auto < out/transform-dis-cases-$1.bin + + diff --git a/test/transform-dis-cases-i386.S b/test/transform-dis-cases-i386.S index 57707cc..3e468d4 100644 --- a/test/transform-dis-cases-i386.S +++ b/test/transform-dis-cases-i386.S @@ -10,8 +10,10 @@ GIVEN jmp 0f; 0: nop EXPECT_ERR GIVEN jne .+0x1000 -/* we expect to generate an unnecessarily long jump, so hardcode it */ -EXPECT 2: .byte 0x0f, 0x85; .long 2; jmp 1f; 0: jmp 2b+0x1000; 1: +/* we expect to generate an unnecessarily long jump, so hardcode it the 0x10000 + * is because we pretend our trampoline is 0x10000 bytes before the original + * function */ +EXPECT 2: .byte 0x0f, 0x85; .long 2; jmp 1f; 0: jmp .+0x10000+0x1000-8; 1: -GIVEN loopne 0xdead0080 -EXPECT loopne 0f; jmp 1f; 0: jmp 0xdead1000; 1: +GIVEN loopne .+0x80 +EXPECT loopne 0f; jmp 1f; 0: jmp .+0x10000+0x80-4; 1: |