[glibc] hurd: Fix build after __pread64 usage in the dynamic loader

[Florian Weimer <fw at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=3007ad2140256e83918ce531435385fa003e9fce

commit 3007ad2140256e83918ce531435385fa003e9fce
Author: Florian Weimer <fweimer@redhat.com>
Date:   Thu Oct 24 15:51:29 2019 +0200

    hurd: Fix build after __pread64 usage in the dynamic loader
    
    Commit 95c1056962a3f2297c94ce47f0eaf0c5b6563231 ("elf: Use nocancel
    pread64() instead of lseek()+read()") added calls to __pread64 to
    the dynamic loader.  On Hurd, this needs an implementation in the
    dynamic loader because the rtld-pread64 rebuild pulls in too many
    symbols.
    
    Fixes: 95c1056962a3f2297c94ce47f0eaf0c5b6563231
    Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

Diff:
---
 sysdeps/mach/hurd/dl-sysdep.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
index 219475a..719d603 100644
--- a/sysdeps/mach/hurd/dl-sysdep.c
+++ b/sysdeps/mach/hurd/dl-sysdep.c
@@ -357,9 +357,9 @@ __close (int fd)
   return 0;
 }
 
-check_no_hidden(__read);
+check_no_hidden(__pread64);
 __ssize_t weak_function
-__read (int fd, void *buf, size_t nbytes)
+__pread64 (int fd, void *buf, size_t nbytes, off64_t offset)
 {
   error_t err;
   char *data;
@@ -367,7 +367,7 @@ __read (int fd, void *buf, size_t nbytes)
 
   data = buf;
   nread = nbytes;
-  err = __io_read ((mach_port_t) fd, &data, &nread, -1, nbytes);
+  err = __io_read ((mach_port_t) fd, &data, &nread, offset, nbytes);
   if (err)
     return __hurd_fail (err);
 
@@ -379,6 +379,14 @@ __read (int fd, void *buf, size_t nbytes)
 
   return nread;
 }
+libc_hidden_weak (__pread64)
+
+check_no_hidden(__read);
+__ssize_t weak_function
+__read (int fd, void *buf, size_t nbytes)
+{
+  return __pread64 (fd, buf, nbytes, -1);
+}
 libc_hidden_weak (__read)
 
 check_no_hidden(__write);