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runtime: adjust frame pointer on stack copy on ARM64

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Frame pointer is enabled on ARM64. When copying stacks, the
saved frame pointers need to be adjusted.

Updates #39524, #40044.
Fixes #58432.

Change-Id: I73651fdfd1a6cccae26a5ce02e7e86f6c2fb9bf7
Reviewed-on: https://go-review.googlesource.com/c/go/+/241158
Reviewed-by: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
This commit is contained in:
Cherry Zhang 2020-07-06 16:03:33 -04:00 • committed by Cherry Mui
parent 1064335047
commit a41a29ad19
5 changed files with 96 additions and 4 deletions
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26
src/runtime/stack.go
View file

@ -537,7 +537,7 @@ var ptrnames = []string{
// +------------------+ <- frame->argp
// | return address |
// +------------------+
// | caller's BP (*) | (*) if framepointer_enabled && varp < sp
// | caller's BP (*) | (*) if framepointer_enabled && varp > sp
// +------------------+ <- frame->varp
// | locals |
// +------------------+
@ -549,6 +549,8 @@ var ptrnames = []string{
// | args from caller |
// +------------------+ <- frame->argp
// | caller's retaddr |
// +------------------+
// | caller's FP (*) | (*) on ARM64, if framepointer_enabled && varp > sp
// +------------------+ <- frame->varp
// | locals |
// +------------------+
@ -556,6 +558,9 @@ var ptrnames = []string{
// +------------------+
// | return address |
// +------------------+ <- frame->sp
//
// varp > sp means that the function has a frame;
// varp == sp means frameless function.
type adjustinfo struct {
old stack
@ -673,9 +678,8 @@ func adjustframe(frame *stkframe, adjinfo *adjustinfo) {
adjustpointers(unsafe.Pointer(frame.varp-size), &locals, adjinfo, f)
}
// Adjust saved base pointer if there is one.
// TODO what about arm64 frame pointer adjustment?
if goarch.ArchFamily == goarch.AMD64 && frame.argp-frame.varp == 2*goarch.PtrSize {
// Adjust saved frame pointer if there is one.
if (goarch.ArchFamily == goarch.AMD64 || goarch.ArchFamily == goarch.ARM64) && frame.argp-frame.varp == 2*goarch.PtrSize {
if stackDebug >= 3 {
print(" saved bp\n")
}
@ -689,6 +693,10 @@ func adjustframe(frame *stkframe, adjinfo *adjustinfo) {
throw("bad frame pointer")
}
}
// On AMD64, this is the caller's frame pointer saved in the current
// frame.
// On ARM64, this is the frame pointer of the caller's caller saved
// by the caller in its frame (one word below its SP).
adjustpointer(adjinfo, unsafe.Pointer(frame.varp))
}
@ -750,7 +758,17 @@ func adjustctxt(gp *g, adjinfo *adjustinfo) {
throw("bad top frame pointer")
}
}
oldfp := gp.sched.bp
adjustpointer(adjinfo, unsafe.Pointer(&gp.sched.bp))
if GOARCH == "arm64" {
// On ARM64, the frame pointer is saved one word *below* the SP,
// which is not copied or adjusted in any frame. Do it explicitly
// here.
if oldfp == gp.sched.sp-goarch.PtrSize {
memmove(unsafe.Pointer(gp.sched.bp), unsafe.Pointer(oldfp), goarch.PtrSize)
adjustpointer(adjinfo, unsafe.Pointer(gp.sched.bp))
}
}
}
func adjustdefers(gp *g, adjinfo *adjustinfo) {