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QEMU main repository: Please see https://www.qemu.org/docs/master/devel/submitting-a-patch.html for how to submit changes to QEMU. Pull Requests are ignored. Please only use release tarballs from the QEMU website. http://www.qemu.org

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Laurent Vivier 7f254c5cb8 linux-user: remove useless padding in flock64 structure 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, hppa, s390x] For ARM, the target_flock64 becomes the EABI definition, so we need to define the OABI one in place of the EABI one and use it when it is needed. I have also fixed the alignment value for sh4 (to align llong on 4 bytes) (see `c2e3dee6e0` "linux-user: Define target alignment size") [We should check alignment properties for cris, nios2 and or1k] Signed-off-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20180502215730.28162-1-laurent@vivier.eu>	8 years ago
..
abitypes.h	linux-user: remove useless padding in flock64 structure	8 years ago
thunk.h	thunk: Rename args and fields in host-target bitmask conversion code	10 years ago

Laurent Vivier 7f254c5cb8 linux-user: remove useless padding in flock64 structure

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, hppa, s390x]

For ARM, the target_flock64 becomes the EABI definition, so we need to
define the OABI one in place of the EABI one and use it when it is
needed.

I have also fixed the alignment value for sh4 (to align llong on 4 bytes)
(see c2e3dee6e0 "linux-user: Define target alignment size")
[We should check alignment properties for cris, nios2 and or1k]

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180502215730.28162-1-laurent@vivier.eu>

8 years ago

abitypes.h linux-user: remove useless padding in flock64 structure 8 years ago

thunk.h thunk: Rename args and fields in host-target bitmask conversion code 10 years ago