From 826fa3e515b46237ae61329bad1ba7da3cf28b51 Mon Sep 17 00:00:00 2001 From: Than McIntosh Date: Mon, 13 Mar 2023 12:02:36 -0400 Subject: [release-branch.go1.19] cmd/link/internal/arm: fix off-by-1 in trampoline reachability computation Tweak the code in trampoline generation that determines if a given call branch will reach, changing the lower limit guard from "x < -0x800000" to "x <= -0x800000". This is to resolve linking failures when the computed displacement is exactly -0x800000, which results in errors of the form .../ld.gold: internal error in arm_branch_common, at ../../gold/arm.cc:4079 when using the Gold linker, and ...:(.text+0x...): relocation truncated to fit: R_ARM_CALL against `runtime.morestack_noctxt' when using the bfd linker. Fixes #59058. Updates #59034. Updates #58425. Change-Id: I8a76986b38727df1b961654824c2af23f06b9fcf Reviewed-on: https://go-review.googlesource.com/c/go/+/475957 Run-TryBot: Than McIntosh TryBot-Result: Gopher Robot Reviewed-by: Cherry Mui (cherry picked from commit f26bf203ac67fd917f2eb992baa1cb2d01edf3c8) Reviewed-on: https://go-review.googlesource.com/c/go/+/476935 --- src/cmd/link/internal/arm/asm.go | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/cmd/link/internal/arm/asm.go b/src/cmd/link/internal/arm/asm.go index 6110916fa9..cc61287b0b 100644 --- a/src/cmd/link/internal/arm/asm.go +++ b/src/cmd/link/internal/arm/asm.go @@ -417,7 +417,7 @@ func trampoline(ctxt *ld.Link, ldr *loader.Loader, ri int, rs, s loader.Sym) { t = (ldr.SymValue(rs) + int64(signext24(r.Add()&0xffffff)*4) - (ldr.SymValue(s) + int64(r.Off()))) / 4 } } - if t > 0x7fffff || t < -0x800000 || ldr.SymValue(rs) == 0 || (*ld.FlagDebugTramp > 1 && ldr.SymPkg(s) != ldr.SymPkg(rs)) { + if t > 0x7fffff || t <= -0x800000 || ldr.SymValue(rs) == 0 || (*ld.FlagDebugTramp > 1 && ldr.SymPkg(s) != ldr.SymPkg(rs)) { // direct call too far, need to insert trampoline. // look up existing trampolines first. if we found one within the range // of direct call, we can reuse it. otherwise create a new one. -- cgit v1.2.1