runtime: check for ARM syscall failures

    While we are at it, also update some comments.
    Tested on Linux/ARM builder.

R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/5696047

diff --git a/src/pkg/runtime/sys_linux_arm.s b/src/pkg/runtime/sys_linux_arm.s
index fed963f0dc311014535e9b6621efe6c29887e581..26101d7123be48421cb9f972a29bee6b8a93cb1c 100644 (file)
--- a/src/pkg/runtime/sys_linux_arm.s
+++ b/src/pkg/runtime/sys_linux_arm.s
@@ -8,10 +8,7 @@
 
 #include "zasm_GOOS_GOARCH.h"
 
-// OABI
-//#define SYS_BASE 0x00900000
-
-// EABI
+// for EABI, as we don't support OABI
 #define SYS_BASE 0x0
 
 #define SYS_exit (SYS_BASE + 1)
@@ -40,6 +37,11 @@
 #define ARM_BASE (SYS_BASE + 0x0f0000)
 #define SYS_ARM_cacheflush (ARM_BASE + 2)
 
+TEXT notok<>(SB),7,$0
+       MOVW    $0, R9
+       MOVW    R9, (R9)
+       B       0(PC)
+
 TEXT runtime·open(SB),7,$0
        MOVW    0(FP), R0
        MOVW    4(FP), R1
@@ -104,6 +106,9 @@ TEXT runtime·mmap(SB),7,$0
        MOVW    20(FP), R5
        MOVW    $SYS_mmap2, R7
        SWI     $0
+       MOVW    $0xfffff001, R6
+       CMP             R6, R0
+       RSB.HI  $0, R0
        RET
 
 TEXT runtime·munmap(SB),7,$0
@@ -111,6 +116,9 @@ TEXT runtime·munmap(SB),7,$0
        MOVW    4(FP), R1
        MOVW    $SYS_munmap, R7
        SWI     $0
+       MOVW    $0xfffff001, R6
+       CMP     R6, R0
+       BL.HI   notok<>(SB)
        RET
 
 TEXT runtime·madvise(SB),7,$0
@@ -119,6 +127,9 @@ TEXT runtime·madvise(SB),7,$0
        MOVW    8(FP), R2
        MOVW    $SYS_madvise, R7
        SWI     $0
+       MOVW    $0xfffff001, R6
+       CMP     R6, R0
+       BL.HI   notok<>(SB)
        RET
 
 TEXT runtime·setitimer(SB),7,$0
@@ -270,6 +281,9 @@ TEXT runtime·sigaltstack(SB),7,$0
        MOVW    4(FP), R1
        MOVW    $SYS_sigaltstack, R7
        SWI     $0
+       MOVW    $0xfffff001, R6
+       CMP     R6, R0
+       BL.HI   notok<>(SB)
        RET
 
 TEXT runtime·sigtramp(SB),7,$24
@@ -333,8 +347,8 @@ TEXT runtime·usleep(SB),7,$12
        SWI     $0
        RET
 
-// Use kernel version instead of native armcas in ../../arm.s.
-// See ../../../sync/atomic/asm_linux_arm.s for details.
+// Use kernel version instead of native armcas in asm_arm.s.
+// See ../sync/atomic/asm_linux_arm.s for details.
 TEXT cas<>(SB),7,$0
        MOVW    $0xffff0fc0, PC