On Sat, Oct 22, 2022 at 6:45 AM Sören Tempel <soe...@soeren-tempel.net> wrote:
>
> PING.
>
> soe...@soeren-tempel.net wrote:
> > From: Sören Tempel <soe...@soeren-tempel.net>
> >
> > On glibc-based systems, off_t is a 32-bit type on 32-bit systems and a
> > 64-bit type on 64-bit systems by default. However, on systems using musl
> > libc off_t is unconditionally a 64-bit type. As such, it is insufficient
> > to use a uintptr type for the mmap offset parameter.
> >
> > Presently, the (incorrect) mmap declaration causes a libgo run-time
> > failure on 32-bit musl systems (fatal error: runtime: cannot allocate
> > memory). This commit fixes this run-time error.
> >
> > Signed-off-by: Sören Tempel <soe...@soeren-tempel.net>
> > ---
> > This implements what has been proposed by Ian in a GitHub comment
> > https://github.com/golang/go/issues/51280#issuecomment-1046322011
> >
> > I don't have access to a 32-bit glibc system to test this on but
> > this does seem to work fine on 32-bit and 64-bit musl systems.
Thanks. Committed as follows using _libgo_off_t_type to avoid the
confusion between off_t and off64_t.
Sorry for the delay.
Ian
11a5fc0c76aedb100b5d7ecc7dd4bed33d850bb8
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 5b95b38a541..7e531c3f90b 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-6c188108858e3ae8c8ea8e4cc55427d8cf01bbc8
+5e658f4659c551330ea68f5667e4f951b218f32d
The first line of this file holds the git revision number of the last
merge done from the gofrontend repository.
diff --git a/libgo/go/runtime/mem_gccgo.go b/libgo/go/runtime/mem_gccgo.go
index fa3389d857e..1e84f4f5c56 100644
--- a/libgo/go/runtime/mem_gccgo.go
+++ b/libgo/go/runtime/mem_gccgo.go
@@ -15,7 +15,7 @@ import (
//go:linkname sysFree
//extern mmap
-func sysMmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off
uintptr) unsafe.Pointer
+func sysMmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off
_libgo_off_t_type) unsafe.Pointer
//extern munmap
func munmap(addr unsafe.Pointer, length uintptr) int32
@@ -38,7 +38,7 @@ func init() {
}
func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uintptr)
(unsafe.Pointer, int) {
- p := sysMmap(addr, n, prot, flags, fd, off)
+ p := sysMmap(addr, n, prot, flags, fd, _libgo_off_t_type(off))
if uintptr(p) == _MAP_FAILED {
return nil, errno()
}
@@ -47,6 +47,7 @@ func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd
int32, off uintptr) (u
// Don't split the stack as this method may be invoked without a valid G, which
// prevents us from allocating more stack.
+//
//go:nosplit
func sysAlloc(n uintptr, sysStat *sysMemStat) unsafe.Pointer {
p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE,
mmapFD, 0)
@@ -165,6 +166,7 @@ func sysHugePage(v unsafe.Pointer, n uintptr) {
// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
+//
//go:nosplit
func sysFree(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) {
sysStat.add(-int64(n))
