From ffd178c651b827f24acead02284abbb12f3f723b Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 30 Jun 2020 14:08:22 -0300 Subject: sysv: linux: Add 64-bit time_t variant for shmctl To provide a y2038 safe interface a new symbol __shmctl64 is added and __shmctl is change to call it instead (it adds some extra buffer copying for the 32 bit time_t implementation). Two new structures are added: 1. kernel_shmid64_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. shmid_ds64: this is only for __TIMESIZE != 64 to use along with the 64-bit shmctl. 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 shmid_ds already contains 64-bit time_t fields and will result in just the __shmctl symbol using the __shmctl64 code. The shmid_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 of the 64-bit one. The default 32-bit symbol will allocate and copy the shmid_ds over multiple buffers, but this should be deprecated in favor of the __shmctl64 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. Reviewed-by: Alistair Francis Tested-by: Alistair Francis Tested-by: Carlos O'Donell Reviewed-by: Carlos O'Donell --- .../unix/sysv/linux/bits/types/struct_shmid64_ds.h | 37 ++++++++++++++++++++++ .../unix/sysv/linux/bits/types/struct_shmid_ds.h | 6 ++-- 2 files changed, 40 insertions(+), 3 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/bits/types/struct_shmid64_ds.h (limited to 'sysdeps/unix/sysv/linux/bits') diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_shmid64_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_shmid64_ds.h new file mode 100644 index 0000000000..f71e0d28ff --- /dev/null +++ b/sysdeps/unix/sysv/linux/bits/types/struct_shmid64_ds.h @@ -0,0 +1,37 @@ +/* Generic implementation of the shared memory struct shmid_ds. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _SYS_SHM_H +# error "Never include directly; use instead." +#endif + +#if __TIMESIZE == 64 +# define __shmid64_ds shmid_ds +#else +struct __shmid64_ds +{ + struct ipc_perm shm_perm; /* operation permission struct */ + size_t shm_segsz; /* size of segment in bytes */ + __time64_t shm_atime; /* time of last shmat() */ + __time64_t shm_dtime; /* time of last shmdt() */ + __time64_t shm_ctime; /* time of last change by shmctl() */ + __pid_t shm_cpid; /* pid of creator */ + __pid_t shm_lpid; /* pid of last shmop */ + shmatt_t shm_nattch; /* number of current attaches */ +}; +#endif diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_shmid_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_shmid_ds.h index 61ed4a08c3..836a7d50e9 100644 --- a/sysdeps/unix/sysv/linux/bits/types/struct_shmid_ds.h +++ b/sysdeps/unix/sysv/linux/bits/types/struct_shmid_ds.h @@ -27,11 +27,11 @@ struct shmid_ds size_t shm_segsz; /* size of segment in bytes */ #if __TIMESIZE == 32 __time_t shm_atime; /* time of last shmat() */ - unsigned long int __glibc_reserved1; + unsigned long int __shm_atime_high; __time_t shm_dtime; /* time of last shmdt() */ - unsigned long int __glibc_reserved2; + unsigned long int __shm_dtime_high; __time_t shm_ctime; /* time of last change by shmctl() */ - unsigned long int __glibc_reserved3; + unsigned long int __shm_ctime_high; #else __time_t shm_atime; /* time of last shmat() */ __time_t shm_dtime; /* time of last shmdt() */ -- cgit 1.4.1