[hurd,commited 2/5] hurd: Make read and pread64 cancellable

[Samuel Thibault]

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.
---
 sysdeps/mach/hurd/Makefile           |  3 ++-
 sysdeps/mach/hurd/Versions           |  6 +++++
 sysdeps/mach/hurd/dl-sysdep.c        |  5 ++++
 sysdeps/mach/hurd/i386/ld.abilist    |  1 +
 sysdeps/mach/hurd/i386/localplt.data |  5 +++-
 sysdeps/mach/hurd/not-cancel.h       | 14 +++++++----
 sysdeps/mach/hurd/pread64.c          | 16 ++++++-------
 sysdeps/mach/hurd/pread64_nocancel.c | 35 ++++++++++++++++++++++++++++
 sysdeps/mach/hurd/read.c             | 12 ++++++----
 sysdeps/mach/hurd/read_nocancel.c    | 30 ++++++++++++++++++++++++
 10 files changed, 106 insertions(+), 21 deletions(-)
 create mode 100644 sysdeps/mach/hurd/pread64_nocancel.c
 create mode 100644 sysdeps/mach/hurd/read_nocancel.c

diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile
index 039bcfc041..bf741058f5 100644
--- a/sysdeps/mach/hurd/Makefile
+++ b/sysdeps/mach/hurd/Makefile
@@ -196,7 +196,8 @@ sysdep_routines += cthreads
 endif
 
 ifeq (io, $(subdir))
-sysdep_routines += f_setlk close_nocancel_nostatus
+sysdep_routines += f_setlk close_nocancel_nostatus read_nocancel \
+                  pread64_nocancel
 endif
 
 ifeq ($(subdir),sunrpc)
diff --git a/sysdeps/mach/hurd/Versions b/sysdeps/mach/hurd/Versions
index 1d6633f782..ce873f33f6 100644
--- a/sysdeps/mach/hurd/Versions
+++ b/sysdeps/mach/hurd/Versions
@@ -10,6 +10,7 @@ libc {
   GLIBC_PRIVATE {
     # Functions shared with the dynamic linker
     __access; __access_noerrno; __libc_read; __libc_write; __libc_lseek64;
+    __read_nocancel; __pread64_nocancel;
     __libc_lock_self0; __getcwd;
 
     _dl_init_first;
@@ -32,6 +33,10 @@ ld {
     _exit; _hurd_intr_rpc_mach_msg;
     abort;
   }
+  GLIBC_2.1 {
+    # functions that must be shared with libc
+    __pread64;
+  }
   GLIBC_2.2 {
     # functions that must be shared with libc
     __open64;
@@ -45,6 +50,7 @@ ld {
 
     # functions that must be shared with libc
     __access; __access_noerrno; __libc_read; __libc_write; __libc_lseek64;
+    __read_nocancel; __pread64_nocancel;
     __libc_lock_self0; __getcwd;
   }
 }
diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
index 574e252836..1626cd5928 100644
--- a/sysdeps/mach/hurd/dl-sysdep.c
+++ b/sysdeps/mach/hurd/dl-sysdep.c
@@ -47,6 +47,7 @@
 
 #include <dl-tunables.h>
 #include <not-errno.h>
+#include <not-cancel.h>
 
 extern void __mach_init (void);
 
@@ -359,6 +360,7 @@ __close (int fd)
 }
 
 check_no_hidden(__pread64);
+check_no_hidden(__pread64_nocancel);
 __ssize_t weak_function
 __pread64 (int fd, void *buf, size_t nbytes, off64_t offset)
 {
@@ -381,14 +383,17 @@ __pread64 (int fd, void *buf, size_t nbytes, off64_t 
offset)
   return nread;
 }
 libc_hidden_weak (__pread64)
+weak_alias (__pread64, __pread64_nocancel)
 
 check_no_hidden(__read);
+check_no_hidden(__read_nocancel);
 __ssize_t weak_function
 __read (int fd, void *buf, size_t nbytes)
 {
   return __pread64 (fd, buf, nbytes, -1);
 }
 libc_hidden_weak (__read)
+weak_alias (__read, __read_nocancel)
 
 check_no_hidden(__write);
 __ssize_t weak_function
diff --git a/sysdeps/mach/hurd/i386/ld.abilist 
b/sysdeps/mach/hurd/i386/ld.abilist
index b2be75cbff..b4fce5e5f5 100644
--- a/sysdeps/mach/hurd/i386/ld.abilist
+++ b/sysdeps/mach/hurd/i386/ld.abilist
@@ -6,6 +6,7 @@ GLIBC_2.2.6 __libc_stack_end D 0x4
 GLIBC_2.2.6 __mmap F
 GLIBC_2.2.6 __open F
 GLIBC_2.2.6 __open64 F
+GLIBC_2.2.6 __pread64 F
 GLIBC_2.2.6 __read F
 GLIBC_2.2.6 __sbrk F
 GLIBC_2.2.6 __strtoul_internal F
diff --git a/sysdeps/mach/hurd/i386/localplt.data 
b/sysdeps/mach/hurd/i386/localplt.data
index 541c3f32ae..c9f3ca66f9 100644
--- a/sysdeps/mach/hurd/i386/localplt.data
+++ b/sysdeps/mach/hurd/i386/localplt.data
@@ -19,7 +19,10 @@ ld.so: _dl_catch_exception + REL R_386_GLOB_DAT
 ld.so: __open ?
 ld.so: __open64
 ld.so: __close
-ld.so: __read
+ld.so: __read ?
+ld.so: __read_nocancel
+ld.so: __pread64
+ld.so: __pread64_nocancel
 ld.so: __write
 ld.so: __writev
 ld.so: __libc_lseek64
diff --git a/sysdeps/mach/hurd/not-cancel.h b/sysdeps/mach/hurd/not-cancel.h
index 15acfa3b92..8a8f5a9d3c 100644
--- a/sysdeps/mach/hurd/not-cancel.h
+++ b/sysdeps/mach/hurd/not-cancel.h
@@ -42,10 +42,12 @@
 
 void __close_nocancel_nostatus (int fd);
 
-#define __read_nocancel(fd, buf, n) \
-  __read (fd, buf, n)
-#define __pread64_nocancel(fd, buf, count, offset) \
-  __pread64 (fd, buf, count, offset)
+/* Non cancellable read syscall.  */
+__typeof (__read) __read_nocancel;
+
+/* Non cancellable pread syscall (LFS version).  */
+__typeof (__pread64) __pread64_nocancel;
+
 #define __write_nocancel(fd, buf, n) \
   __write (fd, buf, n)
 #define __writev_nocancel_nostatus(fd, iov, n) \
@@ -55,7 +57,9 @@ void __close_nocancel_nostatus (int fd);
 #define __fcntl64_nocancel(fd, cmd, ...) \
   __fcntl64 (fd, cmd, __VA_ARGS__)
 
-#if IS_IN (libc) || IS_IN (rtld)
+#if IS_IN (libc)
+hidden_proto (__read_nocancel)
+hidden_proto (__pread64_nocancel)
 hidden_proto (__close_nocancel_nostatus)
 #endif
 
diff --git a/sysdeps/mach/hurd/pread64.c b/sysdeps/mach/hurd/pread64.c
index 7683e29c99..e14416e63a 100644
--- a/sysdeps/mach/hurd/pread64.c
+++ b/sysdeps/mach/hurd/pread64.c
@@ -17,19 +17,17 @@
    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>
 
 ssize_t
 __libc_pread64 (int fd, void *buf, size_t nbytes, off64_t offset)
 {
-  error_t err;
-  if (offset < 0)
-    err = EINVAL;
-  else
-    err = HURD_FD_USE (fd, _hurd_fd_read (descriptor, buf, &nbytes, offset));
-  return err ? __hurd_dfail (fd, err) : nbytes;
+  ssize_t ret;
+  int cancel_oldtype = LIBC_CANCEL_ASYNC();
+  ret = __pread64_nocancel (fd, buf, nbytes, offset);
+  LIBC_CANCEL_RESET (cancel_oldtype);
+  return ret;
 }
 
 #ifndef __libc_pread64
diff --git a/sysdeps/mach/hurd/pread64_nocancel.c 
b/sysdeps/mach/hurd/pread64_nocancel.c
new file mode 100644
index 0000000000..f6bc5e62b4
--- /dev/null
+++ b/sysdeps/mach/hurd/pread64_nocancel.c
@@ -0,0 +1,35 @@
+/* Read block from given position in file without changing file pointer.
+   Hurd version.
+   Copyright (C) 2001-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   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 <not-cancel.h>
+
+ssize_t
+__pread64_nocancel (int fd, void *buf, size_t nbytes, off64_t offset)
+{
+  error_t err;
+  if (offset < 0)
+    err = EINVAL;
+  else
+    err = HURD_FD_USE (fd, _hurd_fd_read (descriptor, buf, &nbytes, offset));
+  return err ? __hurd_dfail (fd, err) : nbytes;
+}
+libc_hidden_weak (__pread64_nocancel)
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)
diff --git a/sysdeps/mach/hurd/read_nocancel.c 
b/sysdeps/mach/hurd/read_nocancel.c
new file mode 100644
index 0000000000..1aeae44d41
--- /dev/null
+++ b/sysdeps/mach/hurd/read_nocancel.c
@@ -0,0 +1,30 @@
+/* Copyright (C) 1993-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   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 <not-cancel.h>
+
+/* Read NBYTES into BUF from FD.  Return the number read or -1.  */
+ssize_t
+__read_nocancel (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;
+}
+libc_hidden_weak (__read_nocancel)
-- 
2.26.2