[release-branch.go1.21] cmd/internal/obj/arm64: fix frame pointer restore in epilogue
For leaf but nonzero-frame functions.
Currently we're not restoring it properly. We also need to restore
it before popping the stack frame, so that the frame won't get
clobbered by a signal handler in the meantime.
For #63830
Fixes #65449
Needs a test, but I'm not at all sure how we would actually do that. Leaving for inspiration.
Change-Id: I273a25f2a838f05a959c810145cccc5428eaf164
Reviewed-on: https://go-review.googlesource.com/c/go/+/538635
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Eric Fang <eric.fang@arm.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
(cherry picked from commit c9888bdfe2cdd85d14d7d184863d2e8bc42ff73c)
Reviewed-on: https://go-review.googlesource.com/c/go/+/560735
TryBot-Bypass: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/cmd/internal/obj/arm64/obj7.go b/src/cmd/internal/obj/arm64/obj7.go
index f963f62..f7cca30 100644
--- a/src/cmd/internal/obj/arm64/obj7.go
+++ b/src/cmd/internal/obj/arm64/obj7.go
@@ -826,21 +826,24 @@
p.To = obj.Addr{}
if c.cursym.Func().Text.Mark&LEAF != 0 {
if c.autosize != 0 {
+ // Restore frame pointer.
+ // ADD $framesize-8, RSP, R29
+ p.As = AADD
+ p.From.Type = obj.TYPE_CONST
+ p.From.Offset = int64(c.autosize) - 8
+ p.Reg = REGSP
+ p.To.Type = obj.TYPE_REG
+ p.To.Reg = REGFP
+
+ // Pop stack frame.
+ // ADD $framesize, RSP, RSP
+ p = obj.Appendp(p, c.newprog)
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(c.autosize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REGSP
p.Spadj = -c.autosize
-
- // Frame pointer.
- p = obj.Appendp(p, c.newprog)
- p.As = ASUB
- p.From.Type = obj.TYPE_CONST
- p.From.Offset = 8
- p.Reg = REGSP
- p.To.Type = obj.TYPE_REG
- p.To.Reg = REGFP
}
} else {
aoffset := c.autosize
