hurd: Make read and pread64 cancellable

and add _nocancel variants.

* sysdeps/mach/hurd/pread64.c (__libc_pread64):  Call __pread64_nocancel
surrounded by enabling async cancel, to replace implementation moved to...
* sysdeps/mach/hurd/pread64_nocancel.c (__pread64_nocancel): ... here.
* sysdeps/mach/hurd/read.c (__libc_read): Call __read_nocancel surrounded by
enabling async cancel, to replace implementation moved to...
* sysdeps/mach/hurd/read_nocancel.c (__read_nocancel): ... here.
* sysdeps/mach/hurd/Makefile (sysdep_routines): Add read_nocancel and
pread64_nocancel.
* sysdeps/mach/hurd/not-cancel.h (__read_nocancel, __pread64_nocancel):
Replace macros with prototypes with a hidden proto on libc.

* sysdeps/mach/hurd/dl-sysdep.c: Include <not-cancel.h>.
(__pread64_nocancel): New alias, check that it is not hidden.
(__read_nocancel): New alias, check that it is not hidden.

* sysdeps/mach/hurd/Versions (libc.GLIBC_PRIVATE): Add __read_nocancel and
__pread64_nocancel.
(ld.GLIBC_2.1): Add __pread64.
(ld.GLIBC_PRIVATE): Add __read_nocancel and __pread64_nocancel.
* sysdeps/mach/hurd/i386/ld.abilist (__pread64): Add symbol.
* sysdeps/mach/hurd/i386/localplt.data (__read_nocancel, __pread64,
__pread64_nocancel): Add references.

1 files changed, 7 insertions, 5 deletions

diff --git a/sysdeps/mach/hurd/read.c b/sysdeps/mach/hurd/read.c
index 2e8f92a542..00e574e6d1 100644
--- a/sysdeps/mach/hurd/read.c
+++ b/sysdeps/mach/hurd/read.c
@@ -15,16 +15,18 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <unistd.h>
-#include <hurd/fd.h>
+#include <sysdep-cancel.h>
+#include <not-cancel.h>
 
 /* Read NBYTES into BUF from FD.  Return the number read or -1.  */
 ssize_t
 __libc_read (int fd, void *buf, size_t nbytes)
 {
-  error_t err = HURD_FD_USE (fd, _hurd_fd_read (descriptor, buf, &nbytes, -1));
-  return err ? __hurd_dfail (fd, err) : nbytes;
+  ssize_t ret;
+  int cancel_oldtype = LIBC_CANCEL_ASYNC();
+  ret = __read_nocancel (fd, buf, nbytes);
+  LIBC_CANCEL_RESET (cancel_oldtype);
+  return ret;
 }
 libc_hidden_def (__libc_read)
 weak_alias (__libc_read, __read)