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 --- sysdeps/unix/sysv/linux/include/sys/shm.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/include/sys/shm.h (limited to 'sysdeps/unix/sysv/linux/include') diff --git a/sysdeps/unix/sysv/linux/include/sys/shm.h b/sysdeps/unix/sysv/linux/include/sys/shm.h new file mode 100644 index 0000000000..530a1cdfc9 --- /dev/null +++ b/sysdeps/unix/sysv/linux/include/sys/shm.h @@ -0,0 +1,17 @@ +#ifndef _SYS_SHM_H +#include + +#ifndef _ISOMAC + +# include + +# if __TIMESIZE == 64 +# define __shmctl64 __shmctl +# else +extern int __shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf); +libc_hidden_proto (__shmctl64); +# endif + +#endif /* _ISOMAC */ + +#endif /* _SYS_SHM_H */ -- cgit v1.2.3-70-g09d2