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| author | Russ Cox <rsc@golang.org> | 2019-06-05 14:51:57 -0400 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2019-06-06 19:56:53 +0000 |
| commit | 7d65e3a8533c90e5a3ec3d73734891a18b057fed (patch) | |
| tree | 461b62764aa6344486ed30ee928d53cc31979ac2 /src/runtime/sys_darwin_amd64.s | |
| parent | 47df542fefc355d65659278761d06cb9d5eba235 (diff) | |
| download | go-7d65e3a8533c90e5a3ec3d73734891a18b057fed.tar.gz go-7d65e3a8533c90e5a3ec3d73734891a18b057fed.zip | |
runtime: document, fix libc error checks on macOS
It matters whether we are calling a function that would
return a 32-bit or 64-bit -1 on error. A few sites were wrong
and this key detail was omitted from syscall/syscallX docs.
Change-Id: I48a421b6cc4d2d2b5e58f790cc947e3cb2f98940
Reviewed-on: https://go-review.googlesource.com/c/go/+/180841
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/runtime/sys_darwin_amd64.s')
| -rw-r--r-- | src/runtime/sys_darwin_amd64.s | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s index 016b056eb3..bbe6bc14bf 100644 --- a/src/runtime/sys_darwin_amd64.s +++ b/src/runtime/sys_darwin_amd64.s @@ -369,7 +369,7 @@ TEXT runtime·kevent_trampoline(SB),NOSPLIT,$0 MOVQ 40(DI), R9 // arg 6 ts MOVL 0(DI), DI // arg 1 kq CALL libc_kevent(SB) - CMPQ AX, $-1 + CMPL AX, $-1 JNE ok CALL libc_error(SB) MOVLQSX (AX), AX // errno @@ -556,6 +556,9 @@ TEXT runtime·pthread_cond_signal_trampoline(SB),NOSPLIT,$0 // } // syscall must be called on the g0 stack with the // C calling convention (use libcCall). +// +// syscall expects a 32-bit result and tests for 32-bit -1 +// to decide there was an error. TEXT runtime·syscall(SB),NOSPLIT,$0 PUSHQ BP MOVQ SP, BP @@ -603,6 +606,9 @@ ok: // } // syscallX must be called on the g0 stack with the // C calling convention (use libcCall). +// +// syscallX is like syscall but expects a 64-bit result +// and tests for 64-bit -1 to decide there was an error. TEXT runtime·syscallX(SB),NOSPLIT,$0 PUSHQ BP MOVQ SP, BP @@ -689,6 +695,9 @@ ok: // } // syscall6 must be called on the g0 stack with the // C calling convention (use libcCall). +// +// syscall6 expects a 32-bit result and tests for 32-bit -1 +// to decide there was an error. TEXT runtime·syscall6(SB),NOSPLIT,$0 PUSHQ BP MOVQ SP, BP @@ -739,6 +748,9 @@ ok: // } // syscall6X must be called on the g0 stack with the // C calling convention (use libcCall). +// +// syscall6X is like syscall6 but expects a 64-bit result +// and tests for 64-bit -1 to decide there was an error. TEXT runtime·syscall6X(SB),NOSPLIT,$0 PUSHQ BP MOVQ SP, BP |