From 71aadfb8aef6e2c944fbcbc3c9646e08bfb2fb08 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 13 Jul 2020 09:13:12 -0300 Subject: linux: Consolidate xstat{64} The LFS support is implemented on xstat64.c, instead of xstat.c for 64-bit architectures. The xstat.c implements the non-LFS it is no-op for !XSTAT_IS_XSTAT64. The generic non-LFS implementation handle two cases: 1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and nios): it issues __NR_fstat64 plus handle the overflow on st_ino, st_size, or st_blocks. It only handles _STAT_VER_KERNEL. 2. Old KABIs with old non-LFS support (arm, i386, hppa, m68k, microblaze, s390, sh, powerpc, and sparc32). For _STAT_VER_KERNEL it issues __NR_stat, otherwise it issues __NR_stat64 and convert to non-LFS stat struct handling possible overflows on st_ino, st_size, or st_blocks. Also the non-LFS mips is an outlier and it has its own implementation since _STAT_VER_LINUX requires a different conversion function (it uses the kernel_stat as the syscall argument since its exported ABI is different than the kernel one for both non-LFS and LFS implementation). The generic LFS implementation handles multiple cases: 1. XSTAT_IS_XSTAT64 being 1: 1.1. Old 64-bit kABI (ia64, powerpc64*, s390x, x86_64): it issues __NR_stat for _STAT_VER_KERNEL or _STAT_VER_LINUX. 1.2. Old 64-bit kABI with defines __NR_stat64 instead of __NR_stat (sparc64): it issues __NR_stat for _STAT_VER_KERNEL or __NR_stat64 and convert to struct stat64. 1.3. New kABIs which uses generic 64-bit Linux ABI (aarch64 and riscv64): it issues __NR_newfstatat and only for _STAT_VER_KERNEL. 1.4. New 32-bit kABIs with only 64-bit time_t support (arc and riscv32): it issues __NR_statx and covert to struct stat64. 2. Old ABIs with XSTAT_IS_XSTAT64 being 0: 2.1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and nios2): it issues __NR_fstatat64 for _STAT_VER_KERNEL. 2.2. Old kABIs with old non-LFS support (arm, i386, hppa, m68k, microblaze, s390, sh, mips32, powerpc32, and sparc32): it issues __NR_stat64. Also, two special cases requires specific LFS implementations: 1. alpha: it requires to handle _STAT_VER_KERNEL64 to call __NR_stat64 or use the kernel_stat with __NR_stat otherwise. 2. mips64: as for non-LFS implementation its ABIs differ from glibc exported one, which requires an specific conversion function to handle the kernel_stat. Checked with a build for all affected ABIs. I also checked on x86_64, i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x. Reviewed-by: Lukasz Majewski --- sysdeps/unix/sysv/linux/xstatover.h | 67 +++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/xstatover.h (limited to 'sysdeps/unix/sysv/linux/xstatover.h') diff --git a/sysdeps/unix/sysv/linux/xstatover.h b/sysdeps/unix/sysv/linux/xstatover.h new file mode 100644 index 0000000000..20178114f9 --- /dev/null +++ b/sysdeps/unix/sysv/linux/xstatover.h @@ -0,0 +1,67 @@ +/* Overflow tests for stat, statfs, and lseek functions. + 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 + . */ + +#include +#include + +/* Test for overflows of structures where we ask the kernel to fill them + in with standard 64-bit syscalls but return them through APIs that + only expose the low 32 bits of some fields. */ + +static inline off_t lseek_overflow (loff_t res) +{ + off_t retval = (off_t) res; + if (retval == res) + return retval; + + __set_errno (EOVERFLOW); + return (off_t) -1; +} + +static inline int stat_overflow (struct stat *buf) +{ +#if defined __INO_T_MATCHES_INO64_T || !STAT_IS_KERNEL_STAT + return 0; +#else + if (buf->__st_ino_pad == 0 && buf->__st_size_pad == 0 + && buf->__st_blocks_pad == 0) + return 0; + + __set_errno (EOVERFLOW); + return -1; +#endif +} + +/* Note that f_files and f_ffree may validly be a sign-extended -1. */ +static inline int statfs_overflow (struct statfs *buf) +{ +#if __STATFS_MATCHES_STATFS64 || !STAT_IS_KERNEL_STAT + return 0; +#else + if (buf->__f_blocks_pad == 0 && buf->__f_bfree_pad == 0 + && buf->__f_bavail_pad == 0 + && (buf->__f_files_pad == 0 + || (buf->f_files == -1U && buf->__f_files_pad == -1)) + && (buf->__f_ffree_pad == 0 + || (buf->f_ffree == -1U && buf->__f_ffree_pad == -1))) + return 0; + + __set_errno (EOVERFLOW); + return -1; +#endif +} -- cgit v1.2.3-70-g09d2