From 7f254c5cb80bc478794a4c3d7fe5d503b033be13 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 2 May 2018 23:57:30 +0200 Subject: 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 <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 #define __USE_LARGEFILE64 #include 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 Reviewed-by: Richard Henderson Message-Id: <20180502215730.28162-1-laurent@vivier.eu> --- include/exec/user/abitypes.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/exec/user') diff --git a/include/exec/user/abitypes.h b/include/exec/user/abitypes.h index ba188608c2..743b8bb9ea 100644 --- a/include/exec/user/abitypes.h +++ b/include/exec/user/abitypes.h @@ -15,7 +15,7 @@ #define ABI_LLONG_ALIGNMENT 2 #endif -#if defined(TARGET_I386) && !defined(TARGET_X86_64) +#if (defined(TARGET_I386) && !defined(TARGET_X86_64)) || defined(TARGET_SH4) #define ABI_LLONG_ALIGNMENT 4 #endif -- cgit v1.2.3-55-g7522