On 05/01/2018 04:53 PM, Laurent Vivier wrote:
> Since commit 8efb2ed5ec ("linux-user: Correct signedness of
> target_flock l_start and l_len fields"), flock64 structure uses
> abi_llong for l_start and l_len in place of "unsigned long long"
> this should force them to be aligned accordingly to the target
> rules. So we can remove the padding field and the QEMU_PACKED
> attribute.
>
> I have compared the result of the following program before and
> after the change:
>
> cat -> flock64_dump <<EOF
> p/d sizeof(struct target_flock64)
> p/d &((struct target_flock64 *)0)->l_type
> p/d &((struct target_flock64 *)0)->l_whence
> p/d &((struct target_flock64 *)0)->l_start
> p/d &((struct target_flock64 *)0)->l_len
> p/d &((struct target_flock64 *)0)->l_pid
> quit
> EOF
>
> for file in build/all/*-linux-user/qemu-* ; do
> echo $file
> gdb -batch -nx -x flock64_dump $file 2> /dev/null
> done
>
> The sizeof() changes because we remove the QEMU_PACKED.
> The new size is 32 (except for i386 and m68k) and this is
> the real size of "struct flock64" on the target architecture.
>
> The following architectures differ:
> aarch64_be, aarch64, alpha, armeb, arm, cris, hppa, nios2, or1k,
> riscv32, riscv64, s390x.
>
> For a subset of these architectures, I have checked with the following
> program the new structure is the correct one:
>
> #include <stdio.h>
> #define __USE_LARGEFILE64
> #include <fcntl.h>
>
> int main(void)
> {
> printf("struct flock64 %d\n", sizeof(struct flock64));
> printf("l_type %d\n", &((struct flock64 *)0)->l_type);
> printf("l_whence %d\n", &((struct flock64 *)0)->l_whence);
> printf("l_start %d\n", &((struct flock64 *)0)->l_start);
> printf("l_len %d\n", &((struct flock64 *)0)->l_len);
> printf("l_pid %d\n", &((struct flock64 *)0)->l_pid);
> }
>
> [I have checked aarch64, alpha, arm, s390x]
>
> I have also fixed the alignment value for sh4 (to align llong on 4 bytes)
> (see c2e3dee6e0 "linux-user: Define target alignment size")
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
r~
