diff options
| author | Ilya Tocar <ilya.tocar@intel.com> | 2015-10-20 14:52:08 +0300 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2015-10-20 15:48:49 +0000 |
| commit | 7d2c6eb3f53d4fa54587ff52ecb739bd4b13f9ab (patch) | |
| tree | 85e6a07df90bba7bd7900aa8cc57d2418579bcfd | |
| parent | 77b1fef27e736764395633413fc13c14d8fed712 (diff) | |
| download | go-7d2c6eb3f53d4fa54587ff52ecb739bd4b13f9ab.tar.xz | |
cmd/internal/obj/x86: align functions with trap instruction
Align functions with 0xCC (INT $3) - breakpoint instruction,
instead of 0x00, which can disassemble into valid instruction.
Change-Id: Ieda191886efc4aacb86f58bea1169fd1b3b57636
Reviewed-on: https://go-review.googlesource.com/16102
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Gregory Shimansky <gregory.shimansky@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
| -rw-r--r-- | src/cmd/internal/obj/x86/asm6.go | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go index f3be6cdfc7..8159e5934f 100644 --- a/src/cmd/internal/obj/x86/asm6.go +++ b/src/cmd/internal/obj/x86/asm6.go @@ -1754,7 +1754,16 @@ func span6(ctxt *obj.Link, s *obj.LSym) { c = naclpad(ctxt, s, c, -c&31) } - c += -c & (FuncAlign - 1) + // Pad functions with trap instruction, to catch invalid jumps + if c&(FuncAlign-1) != 0 { + v = -c & (FuncAlign - 1) + obj.Symgrow(ctxt, s, int64(c)+int64(v)) + for i := c; i < c+v; i++ { + // 0xCC is INT $3 - breakpoint instruction + s.P[i] = uint8(0xCC) + } + c += v + } s.Size = int64(c) if false { /* debug['a'] > 1 */ |