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>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 404be44..e482574 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6600,10 +6600,10 @@
typedef abi_long to_flock64_fn(abi_ulong target_addr, const struct flock64 *fl);
#if defined(TARGET_ARM) && TARGET_ABI_BITS == 32
-static inline abi_long copy_from_user_eabi_flock64(struct flock64 *fl,
+static inline abi_long copy_from_user_oabi_flock64(struct flock64 *fl,
abi_ulong target_flock_addr)
{
- struct target_eabi_flock64 *target_fl;
+ struct target_oabi_flock64 *target_fl;
short l_type;
if (!lock_user_struct(VERIFY_READ, target_fl, target_flock_addr, 1)) {
@@ -6620,10 +6620,10 @@
return 0;
}
-static inline abi_long copy_to_user_eabi_flock64(abi_ulong target_flock_addr,
+static inline abi_long copy_to_user_oabi_flock64(abi_ulong target_flock_addr,
const struct flock64 *fl)
{
- struct target_eabi_flock64 *target_fl;
+ struct target_oabi_flock64 *target_fl;
short l_type;
if (!lock_user_struct(VERIFY_WRITE, target_fl, target_flock_addr, 0)) {
@@ -11629,9 +11629,9 @@
to_flock64_fn *copyto = copy_to_user_flock64;
#ifdef TARGET_ARM
- if (((CPUARMState *)cpu_env)->eabi) {
- copyfrom = copy_from_user_eabi_flock64;
- copyto = copy_to_user_eabi_flock64;
+ if (!((CPUARMState *)cpu_env)->eabi) {
+ copyfrom = copy_from_user_oabi_flock64;
+ copyto = copy_to_user_oabi_flock64;
}
#endif
