From: Ian Lance Taylor <iant@golang.org>
Date: Sun, 22 Mar 2020 19:57:36 +0000 (-0700)
Subject: [release-branch.go1.14] runtime: negate errno value for mips pipe/pipe2
X-Git-Tag: go1.14.2~12
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=21f453b848405dee74e5d1d8863d28a3db4758f2;p=gostls13.git

[release-branch.go1.14] runtime: negate errno value for mips pipe/pipe2

The callers expect negative errno values, so negate them when necessary.

No test because there is no reasonable way to make pipe/pipe2 fail.
This was reported on a system on which pipe2 returned ENOSYS.

For #37997
Fixes #38005

Change-Id: I3ad6cbbc2521cf495f8df6ec991a3f781122b508
Reviewed-on: https://go-review.googlesource.com/c/go/+/224592
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
(cherry picked from commit 20b46c7c697ce9d833141abe9aa0ea6101f00ae2)
Reviewed-on: https://go-review.googlesource.com/c/go/+/225419
---

diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
index 723cfe43d9..6668a0fd86 100644
--- a/src/runtime/sys_linux_mips64x.s
+++ b/src/runtime/sys_linux_mips64x.s
@@ -117,6 +117,8 @@ TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
 	MOVV	R0, R5
 	MOVV	$SYS_pipe2, R2
 	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
 	MOVW	R2, errno+8(FP)
 	RET
 
@@ -126,6 +128,8 @@ TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
 	MOVW	flags+0(FP), R5
 	MOVV	$SYS_pipe2, R2
 	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
 	MOVW	R2, errno+16(FP)
 	RET
 
diff --git a/src/runtime/sys_linux_mipsx.s b/src/runtime/sys_linux_mipsx.s
index 15893a7a28..fab2ab3892 100644
--- a/src/runtime/sys_linux_mipsx.s
+++ b/src/runtime/sys_linux_mipsx.s
@@ -118,6 +118,7 @@ TEXT runtime·pipe(SB),NOSPLIT,$0-12
 	MOVW	$-1, R1
 	MOVW	R1, r+0(FP)
 	MOVW	R1, w+4(FP)
+	SUBU	R2, R0, R2	// caller expects negative errno
 	MOVW	R2, errno+8(FP)
 	RET
 pipeok:
@@ -132,6 +133,8 @@ TEXT runtime·pipe2(SB),NOSPLIT,$0-16
 	MOVW	flags+0(FP), R5
 	MOVW	$SYS_pipe2, R2
 	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBU	R2, R0, R2	// caller expects negative errno
 	MOVW	R2, errno+12(FP)
 	RET