pwrite does not work right under qemu-sh4

[Bruno Haible]

The pwrite system call has no effect when writing to a non-zero file position, in a program running under qemu-sh4 (version 2.9.0).

How to reproduce:
- Compile the program:
  sh4-linux-gnu-gcc-5 -O -Wall -static -o test-pwrite test-pwrite.c
- Set environment variable for using qemu-sh4 (actually not needed, since the program is statically linked here).
- ~/inst-qemu/2.9.0/bin/qemu-sh4 test-pwrite

Expected output:
buf = 01W3456789

Actual output:
buf = 0123456789
test-pwrite.c:56: assertion 'strcmp ("01W3456789",buf) == 0' failed
qemu: uncaught target signal 6 (Aborted) - core dumped

[Bruno Haible (bruno-clisp)]

In case it matters: My host platform is Linux/x86_64.

[Bruno Haible (bruno-clisp)]

The behaviour in qemu-2.10 is the same as in qemu-2.9.

[John Paul Adrian Glaubitz (glaubitz)]

This might be related to this fix:

> https://git.qemu.org/?p=qemu.git;a=commit;h=8bf8e9df4a7d82c7a47cc961c9cdee1615595de0

FWIW, if you're interested in sh4, please join #debian-ports on OFTC and subscribe to the debian-superh mailing list. We're doing lots of sh4 development and testing QEMU in Debian.

[Bruno Haible (bruno-clisp)]

Works fine in qemu-2.11:
$ ~/inst-qemu/2.11.0/bin/qemu-sh4 test-pwrite
buf = 01W3456789