proc: Improved prologue detection for big stackframes (#690)

Improved prologue detection for big stackframes and added references to
the function of the compiler that inserts the prologue.
This commit is contained in:
Alessandro Arzilli
2017-01-05 20:39:34 +01:00
committed by Derek Parker
parent 464d6c2783
commit fd1df948fa

View File

@ -117,13 +117,30 @@ func (thread *Thread) resolveCallArg(inst *ArchInst, currentGoroutine bool, regs
type instrseq []x86asm.Op
var windowsPrologue = instrseq{x86asm.MOV, x86asm.MOV, x86asm.LEA, x86asm.CMP, x86asm.JBE}
var windowsPrologue2 = instrseq{x86asm.MOV, x86asm.MOV, x86asm.CMP, x86asm.JBE}
var windowsPrologue3 = instrseq{x86asm.MOV, x86asm.MOV, x86asm.MOV, x86asm.CMP, x86asm.JE}
var unixPrologue = instrseq{x86asm.MOV, x86asm.LEA, x86asm.CMP, x86asm.JBE}
var unixPrologue2 = instrseq{x86asm.MOV, x86asm.CMP, x86asm.JBE}
var unixPrologue3 = instrseq{x86asm.MOV, x86asm.MOV, x86asm.CMP, x86asm.JE}
var prologues = []instrseq{windowsPrologue, windowsPrologue2, windowsPrologue3, unixPrologue, unixPrologue2, unixPrologue3}
// Possible stacksplit prologues are inserted by stacksplit in
// $GOROOT/src/cmd/internal/obj/x86/obj6.go.
// The stacksplit prologue will always begin with loading curg in CX, this
// instruction is added by load_g_cx in the same file and is either 1 or 2
// MOVs.
var prologues []instrseq
func init() {
var tinyStacksplit = instrseq{x86asm.CMP, x86asm.JBE}
var smallStacksplit = instrseq{x86asm.LEA, x86asm.CMP, x86asm.JBE}
var bigStacksplit = instrseq{x86asm.MOV, x86asm.CMP, x86asm.JE, x86asm.LEA, x86asm.SUB, x86asm.CMP, x86asm.JBE}
var unixGetG = instrseq{x86asm.MOV}
var windowsGetG = instrseq{x86asm.MOV, x86asm.MOV}
prologues = make([]instrseq, 0, 2*3)
for _, getG := range []instrseq{unixGetG, windowsGetG} {
for _, stacksplit := range []instrseq{tinyStacksplit, smallStacksplit, bigStacksplit} {
prologue := make(instrseq, 0, len(getG)+len(stacksplit))
prologue = append(prologue, getG...)
prologue = append(prologue, stacksplit...)
prologues = append(prologues, prologue)
}
}
}
// FirstPCAfterPrologue returns the address of the first instruction after the prologue for function fn
// If sameline is set FirstPCAfterPrologue will always return an address associated with the same line as fn.Entry
@ -156,8 +173,9 @@ func (dbp *Process) FirstPCAfterPrologue(fn *gosym.Func, sameline bool) (uint64,
}
func checkPrologue(s []AsmInstruction, prologuePattern instrseq) bool {
line := s[0].Loc.Line
for i, op := range prologuePattern {
if s[i].Inst.Op != op {
if s[i].Inst.Op != op || s[i].Loc.Line != line {
return false
}
}