The MIPS n32 ABI is basically n64 with the address space (i.e. pointer
width) shrinked to 32 bits. Meanwhile the current code treats it as
o32-like based on TARGET_ABI_BITS, which causes problems with n32
syscalls utilizing 64-bit offsets, like pread64, affecting most (if not
all) recently built n32 binaries.
This partially solves issue #909 ("qemu-mipsn32(el) user mode emulator
fails to execute any recently built n32 binaries"); with this change
applied, the built qemu-mipsn32el is able to progress beyond the
pread64, and finish _dl_start_user for the "getting ld.so load libc.so"
case. The program later dies with SIGBUS, though, due to _dl_start_user
not maintaining stack alignment after removing ld.so itself from argv,
and qemu-user starting to enforce alignment recently, but that is
orthogonal to the issue here; the more common case of chrooting is
working, verified with my own-built Gentoo n32 sysroot. (Depending on
the exact ISA used, one may have to explicitly specify QEMU_CPU, which
is the case for my chroot.)
Buglink:https://gitlab.com/qemu-project/qemu/-/issues/909
Signed-off-by: WANG Xuerui<xen0n@gentoo.org>
Cc: Laurent Vivier<laurent@vivier.eu>
Cc: Philippe Mathieu-Daudé<f4bug@amsat.org>
Cc: Jiaxun Yang<jiaxun.yang@flygoat.com>
Cc: Andreas K. Hüttel<dilfridge@gentoo.org>