glibc/sysdeps/unix/sysv/linux/struct_kernel_msqid64_ds.h

/* Analogous to kernel struct msqid64_ds used on msgctl.  It is only used
   for 32-bit architectures on 64-bit time_t msgctl64 implementation.  */
struct kernel_msqid64_ds
{
  struct ipc_perm msg_perm;
  unsigned long int msg_stime;
  unsigned long int msg_stime_high;
  unsigned long int msg_rtime;
  unsigned long int msg_rtime_high;
  unsigned long int msg_ctime;
  unsigned long int msg_ctime_high;
  unsigned long int msg_cbytes;
  unsigned long int msg_qnum;
  unsigned long int msg_qbytes;
  __pid_t msg_lspid;
  __pid_t msg_lrpid;
  unsigned long int __unused4;
  unsigned long int __unused5;
};
sysv: linux: Add 64-bit time_t variant for msgctl To provide a y2038 safe interface a new symbol __msgctl64 is added and __msgctl is change to call it instead (it adds some extra buffer coping for the 32 bit time_t implementation). Two new structures are added: 1. kernel_msqid64_ds: used internally only on 32-bit architectures to issue the syscall. A handful of architectures (hppa, i386, mips, powerpc32, and sparc32) require specific implementations due to their kernel ABI. 2. msqid_ds64: this is only for __TIMESIZE != 64 to use along with the 64-bit msgctl. It is different than the kernel struct because the exported 64-bit time_t might require different alignment depending on the architecture ABI. So the resulting implementation does: 1. For 64-bit architectures it assumes msqid_ds already contains 64-bit time_t fields and will result in just the __msgctl symbol using the __msgctl64 code. The msgid_ds argument is passed as-is to the syscall. 2. For 32-bit architectures with default 64-bit time_t (newer ABIs such riscv32 or arc), it will also result in only one exported symbol but with the required high/low time handling. 3. Finally for 32-bit architecture with both 32-bit and 64-bit time_t support we follow the already set way to provide one symbol with 64-bit time_t support and implement the 32-bit time_t support using the 64-bit time_t. The default 32-bit symbol will allocate and copy the msqid_ds over multiple buffers, but this should be deprecated in favor of the __msgctl64 anyway. Checked on i686-linux-gnu and x86_64-linux-gnu. I also did some sniff tests on powerpc, powerpc64, mips, mips64, armhf, sparcv9, and sparc64. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Tested-by: Alistair Francis <alistair.francis@wdc.com> 2020-06-30 12:20:48 +00:00			`/* Analogous to kernel struct msqid64_ds used on msgctl. It is only used`
			`for 32-bit architectures on 64-bit time_t msgctl64 implementation. */`
			`struct kernel_msqid64_ds`
			`{`
			`struct ipc_perm msg_perm;`
			`unsigned long int msg_stime;`
			`unsigned long int msg_stime_high;`
			`unsigned long int msg_rtime;`
			`unsigned long int msg_rtime_high;`
			`unsigned long int msg_ctime;`
			`unsigned long int msg_ctime_high;`
			`unsigned long int msg_cbytes;`
			`unsigned long int msg_qnum;`
			`unsigned long int msg_qbytes;`
			`__pid_t msg_lspid;`
			`__pid_t msg_lrpid;`
			`unsigned long int __unused4;`
			`unsigned long int __unused5;`
			`};`