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> --- linux-user/arm/target_structs.h | 7 +++++++ linux-user/syscall.c | 14 +++++++------- linux-user/syscall_defs.h | 25 ++++--------------------- 3 files changed, 18 insertions(+), 28 deletions(-) (limited to 'linux-user') diff --git a/linux-user/arm/target_structs.h b/linux-user/arm/target_structs.h index 0bf034cc25..9a3dbce03d 100644 --- a/linux-user/arm/target_structs.h +++ b/linux-user/arm/target_structs.h @@ -49,4 +49,11 @@ struct target_shmid_ds { abi_ulong __unused5; }; +struct target_oabi_flock64 { + abi_short l_type; + abi_short l_whence; + abi_llong l_start; + abi_llong l_len; + abi_int l_pid; +} QEMU_PACKED; #endif diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 404be44ad5..e4825747f9 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6600,10 +6600,10 @@ typedef abi_long from_flock64_fn(struct flock64 *fl, abi_ulong target_addr); 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 @@ static inline abi_long copy_from_user_eabi_flock64(struct flock64 *fl, 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 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, 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 diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h index 23f5bccf0e..361bb83a29 100644 --- a/linux-user/syscall_defs.h +++ b/linux-user/syscall_defs.h @@ -2649,29 +2649,12 @@ struct target_flock { }; struct target_flock64 { - short l_type; - short l_whence; -#if defined(TARGET_PPC) || defined(TARGET_X86_64) || defined(TARGET_MIPS) \ - || defined(TARGET_SPARC) || defined(TARGET_HPPA) \ - || defined(TARGET_MICROBLAZE) || defined(TARGET_TILEGX) \ - || defined(TARGET_XTENSA) - int __pad; -#endif - abi_llong l_start; - abi_llong l_len; - int l_pid; -} QEMU_PACKED; - -#ifdef TARGET_ARM -struct target_eabi_flock64 { - short l_type; - short l_whence; - int __pad; + abi_short l_type; + abi_short l_whence; abi_llong l_start; abi_llong l_len; - int l_pid; -} QEMU_PACKED; -#endif + abi_int l_pid; +}; struct target_f_owner_ex { int type; /* Owner type of ID. */ -- cgit v1.2.1