runtime: fix syscall error returns on mips/mips64/ppc64

The linux syscall functions used in runtime are designed around the calling
convention of returning errors as negative numbers. On some other systems
(like mips and ppc) the actual syscalls signal errors in other ways. This
means that the assembly implementations of the syscall functions on these
platforms need to transform the return values in the error cases to match
the expected negative errno values. This was addressed for certain syscalls
in https://golang.org/cl/19455 and https://golang.org/cl/89235. This patch
handles the rest of the syscall functions in sys_linux_*.s that return any
value for mips/mips64/ppc64.

Fixes #23446

Change-Id: I302100261231f76d5850ab2c2ea080170d7dba72
GitHub-Last-Rev: e358e2b08c76897b13f917cfa12b5085e20337f9
GitHub-Pull-Request: golang/go#26606
Reviewed-on: https://go-review.googlesource.com/125895
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
index 9ce810a6b6c5ea9aebae3a37fbfb290bb57348df..8e64f1c562e642b621d6e6a767125d5f4d296ddf 100644 (file)
--- a/src/runtime/sys_linux_mips64x.s
+++ b/src/runtime/sys_linux_mips64x.s
@@ -218,6 +218,8 @@ TEXT runtime·rt_sigaction(SB),NOSPLIT|NOFRAME,$0-36
        MOVV    size+24(FP), R7
        MOVV    $SYS_rt_sigaction, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+32(FP)
        RET
 
@@ -299,6 +301,8 @@ TEXT runtime·futex(SB),NOSPLIT|NOFRAME,$0
        MOVW    val3+32(FP), R9
        MOVV    $SYS_futex, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+40(FP)
        RET
 
@@ -321,6 +325,8 @@ TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0
 
        MOVV    $SYS_clone, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
 
        // In parent, return.
        BEQ     R2, 3(PC)
@@ -383,6 +389,8 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT|NOFRAME,$0
        MOVV    buf+16(FP), R6
        MOVV    $SYS_sched_getaffinity, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+24(FP)
        RET
 
@@ -391,6 +399,8 @@ TEXT runtime·epollcreate(SB),NOSPLIT|NOFRAME,$0
        MOVW    size+0(FP), R4
        MOVV    $SYS_epoll_create, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+8(FP)
        RET
 
@@ -399,6 +409,8 @@ TEXT runtime·epollcreate1(SB),NOSPLIT|NOFRAME,$0
        MOVW    flags+0(FP), R4
        MOVV    $SYS_epoll_create1, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+8(FP)
        RET
 
@@ -424,6 +436,8 @@ TEXT runtime·epollwait(SB),NOSPLIT|NOFRAME,$0
        MOVV    $0, R8
        MOVV    $SYS_epoll_pwait, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_linux_mipsx.s b/src/runtime/sys_linux_mipsx.s
index 95f63678933336df0b418aba67e3968815eed279..a6bca3bebd8b076fb8ca23b487728e482a5b36e7 100644 (file)
--- a/src/runtime/sys_linux_mipsx.s
+++ b/src/runtime/sys_linux_mipsx.s
@@ -234,6 +234,8 @@ TEXT runtime·rt_sigaction(SB),NOSPLIT,$0-20
        MOVW    size+12(FP), R7
        MOVW    $SYS_rt_sigaction, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+16(FP)
        RET
 
@@ -320,6 +322,8 @@ TEXT runtime·futex(SB),NOSPLIT,$20-28
 
        MOVW    $SYS_futex, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+24(FP)
        RET
 
@@ -351,11 +355,11 @@ TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0-24
 
        MOVW    $SYS_clone, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
 
        // In parent, return.
-       BEQ     R2, 5(PC)
-       SUBU    R2, R0, R3
-       CMOVN   R7, R3, R2
+       BEQ     R2, 3(PC)
        MOVW    R2, ret+20(FP)
        RET
 
@@ -417,6 +421,8 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0-16
        MOVW    buf+8(FP), R6
        MOVW    $SYS_sched_getaffinity, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+12(FP)
        RET
 
@@ -425,6 +431,8 @@ TEXT runtime·epollcreate(SB),NOSPLIT,$0-8
        MOVW    size+0(FP), R4
        MOVW    $SYS_epoll_create, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+4(FP)
        RET
 
@@ -433,6 +441,8 @@ TEXT runtime·epollcreate1(SB),NOSPLIT,$0-8
        MOVW    flags+0(FP), R4
        MOVW    $SYS_epoll_create1, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+4(FP)
        RET
 
@@ -456,6 +466,8 @@ TEXT runtime·epollwait(SB),NOSPLIT,$0-20
        MOVW    timeout+12(FP), R7
        MOVW    $SYS_epoll_wait, R2
        SYSCALL
+       BEQ     R7, 2(PC)
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+16(FP)
        RET
 

diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index b7d34b00daaf7ec1f4180dc68d0d1538ff97b333..483cb8ef9aefd72f039fc7e78341f6b927ba8de6 100644 (file)
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -193,6 +193,8 @@ TEXT runtime·rt_sigaction(SB),NOSPLIT|NOFRAME,$0-36
        MOVD    old+16(FP), R5
        MOVD    size+24(FP), R6
        SYSCALL $SYS_rt_sigaction
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+32(FP)
        RET
 
@@ -388,6 +390,8 @@ TEXT runtime·futex(SB),NOSPLIT|NOFRAME,$0
        MOVD    addr2+24(FP), R7
        MOVW    val3+32(FP), R8
        SYSCALL $SYS_futex
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+40(FP)
        RET
 
@@ -409,6 +413,8 @@ TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0
        MOVD    R7, -32(R4)
 
        SYSCALL $SYS_clone
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
 
        // In parent, return.
        CMP     R3, $0
@@ -472,6 +478,8 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT|NOFRAME,$0
        MOVD    len+8(FP), R4
        MOVD    buf+16(FP), R5
        SYSCALL $SYS_sched_getaffinity
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+24(FP)
        RET
 
@@ -479,6 +487,8 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT|NOFRAME,$0
 TEXT runtime·epollcreate(SB),NOSPLIT|NOFRAME,$0
        MOVW    size+0(FP), R3
        SYSCALL $SYS_epoll_create
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+8(FP)
        RET
 
@@ -486,6 +496,8 @@ TEXT runtime·epollcreate(SB),NOSPLIT|NOFRAME,$0
 TEXT runtime·epollcreate1(SB),NOSPLIT|NOFRAME,$0
        MOVW    flags+0(FP), R3
        SYSCALL $SYS_epoll_create1
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+8(FP)
        RET
 
@@ -507,6 +519,8 @@ TEXT runtime·epollwait(SB),NOSPLIT|NOFRAME,$0
        MOVW    nev+16(FP), R5
        MOVW    timeout+20(FP), R6
        SYSCALL $SYS_epoll_wait
+       BVC     2(PC)
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+24(FP)
        RET