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| author | Clément Chigot <chigot.c@gmail.com> | 2019-11-14 15:43:55 +0100 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2019-12-09 16:41:15 +0000 |
| commit | a3a630b0d2829ab74ac623fc2ae92864bd61d391 (patch) | |
| tree | 85cb59865cae298963be0dfccc27443374d80e33 /src/runtime/os2_aix.go | |
| parent | 590052ba29a6853683533f916284db39f935e4e6 (diff) | |
| download | go-a3a630b0d2829ab74ac623fc2ae92864bd61d391.tar.gz go-a3a630b0d2829ab74ac623fc2ae92864bd61d391.zip | |
runtime: use mprotect in sysMap for aix/ppc64
AIX doesn't allow to mmap an already mmap address. The previous way to
deal with this behavior was to munmap before calling mmap again.
However, mprotect syscall is able to change protections on a memory
range. Thus, memory mapped by sysReserve can be remap using it. Note
that sysMap is always called with a non-nil pointer so mprotect is
always possible.
Updates: #35451
Change-Id: I1fd1e1363d9ed9eb5a8aa7c8242549bd6dad8cd0
Reviewed-on: https://go-review.googlesource.com/c/go/+/207237
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Diffstat (limited to 'src/runtime/os2_aix.go')
| -rw-r--r-- | src/runtime/os2_aix.go | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/runtime/os2_aix.go b/src/runtime/os2_aix.go index 7c3cb27223..31ac6ddf79 100644 --- a/src/runtime/os2_aix.go +++ b/src/runtime/os2_aix.go @@ -38,6 +38,7 @@ var ( //go:cgo_import_dynamic libc_madvise madvise "libc.a/shr_64.o" //go:cgo_import_dynamic libc_malloc malloc "libc.a/shr_64.o" //go:cgo_import_dynamic libc_mmap mmap "libc.a/shr_64.o" +//go:cgo_import_dynamic libc_mprotect mprotect "libc.a/shr_64.o" //go:cgo_import_dynamic libc_munmap munmap "libc.a/shr_64.o" //go:cgo_import_dynamic libc_open open "libc.a/shr_64.o" //go:cgo_import_dynamic libc_pipe pipe "libc.a/shr_64.o" @@ -77,6 +78,7 @@ var ( //go:linkname libc_madvise libc_madvise //go:linkname libc_malloc libc_malloc //go:linkname libc_mmap libc_mmap +//go:linkname libc_mprotect libc_mprotect //go:linkname libc_munmap libc_munmap //go:linkname libc_open libc_open //go:linkname libc_pipe libc_pipe @@ -118,6 +120,7 @@ var ( libc_madvise, libc_malloc, libc_mmap, + libc_mprotect, libc_munmap, libc_open, libc_pipe, @@ -459,6 +462,15 @@ func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) (un } //go:nosplit +func mprotect(addr unsafe.Pointer, n uintptr, prot int32) (unsafe.Pointer, int) { + r, err0 := syscall3(&libc_mprotect, uintptr(addr), uintptr(n), uintptr(prot)) + if r == ^uintptr(0) { + return nil, int(err0) + } + return unsafe.Pointer(r), int(err0) +} + +//go:nosplit func munmap(addr unsafe.Pointer, n uintptr) { r, err := syscall2(&libc_munmap, uintptr(addr), uintptr(n)) if int32(r) == -1 { |