[Bug libfortran/98129] Failure on reading big chunk of /dev/urandom

["tkoenig at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98129

--- Comment #2 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
The problem seems to be related to an early return from the read system call:

strace -e trace=open,read,close ./a.out
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\0\v\2\0\0\0\0\0"...,
832) = 832
close(3)                                = 0
close(3)                                = 0
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\217\0\0\0\0\0\0"...,
832) = 832
close(3)                                = 0
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260/\0\0\0\0\0\0"...,
832) = 832
close(3)                                = 0
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0@*\0\0\0\0\0\0"..., 832)
= 832
close(3)                                = 0
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0`D\2\0\0\0\0\0"..., 832)
= 832
close(3)                                = 0
read(3,
":\312\275\302\373|\204[c`\20\275\230\205\326@\255Mj\263-qd\336\30\300\2G\326\215\333J"...,
40000000) = 33554431
At line 9 of file read.f90
Fortran runtime error: End of file

Error termination. Backtrace:
close(5)                                = 0
close(5)                                = 0
close(6)                                = 0
close(5)                                = 0
close(5)                                = 0
close(5)                                = 0
close(6)                                = 0
close(5)                                = 0
close(6)                                = 0
close(5)                                = 0
#0  0x7fd9847c572f in read_block_direct
        at ../../../trunk/libgfortran/io/transfer.c:664
#1  0x7fd9847c572f in unformatted_read
        at ../../../trunk/libgfortran/io/transfer.c:1127
#2  0x400bf3 in ???
#3  0x400c9c in ???
#4  0x7fd983a46349 in __libc_start_main
        at ../csu/libc-start.c:308
#5  0x400909 in ???
        at ../sysdeps/x86_64/start.S:120
#6  0xffffffffffffffff in ???
close(4)                                = 0
close(3)                                = 0
+++ exited with 2 +++