| From ab1cbd8bcec15b016c96134abbf145cfbeca83ca Mon Sep 17 00:00:00 2001 |
| From: Miklos Szeredi <mszeredi@redhat.com> |
| Date: Thu, 14 May 2020 16:44:25 +0200 |
| Subject: [PATCH] BACKPORT: vfs: add faccessat2 syscall |
| |
| POSIX defines faccessat() as having a fourth "flags" argument, while the |
| linux syscall doesn't have it. Glibc tries to emulate AT_EACCESS and |
| AT_SYMLINK_NOFOLLOW, but AT_EACCESS emulation is broken. |
| |
| Add a new faccessat(2) syscall with the added flags argument and implement |
| both flags. |
| |
| The value of AT_EACCESS is defined in glibc headers to be the same as |
| AT_REMOVEDIR. Use this value for the kernel interface as well, together |
| with the explanatory comment. |
| |
| Also add AT_EMPTY_PATH support, which is not documented by POSIX, but can |
| be useful and is trivial to implement. |
| |
| Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> |
| [Adrian Ratiu: 4.14 linux-headers backport] |
| --- |
| arch/arm/tools/syscall.tbl | 1 + |
| arch/arm64/include/asm/unistd.h | 2 +- |
| arch/arm64/include/asm/unistd32.h | 2 ++ |
| arch/x86/entry/syscalls/syscall_32.tbl | 1 + |
| arch/x86/entry/syscalls/syscall_64.tbl | 1 + |
| include/linux/syscalls.h | 2 ++ |
| include/uapi/asm-generic/unistd.h | 5 ++++- |
| 7 files changed, 12 insertions(+), 2 deletions(-) |
| |
| diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl |
| index 9d87127f33e8..ea8846b73445 100644 |
| --- a/arch/arm/tools/syscall.tbl |
| +++ b/arch/arm/tools/syscall.tbl |
| @@ -435,3 +435,4 @@ |
| 423 common sched_rr_get_interval_time64 sys_sched_rr_get_interval |
| 425 common io_uring_setup sys_io_uring_setup |
| 426 common io_uring_enter sys_io_uring_enter |
| +439 common faccessat2 sys_faccessat2 |
| diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h |
| index 718b1962a1b8..0dd4a8025c08 100644 |
| --- a/arch/arm64/include/asm/unistd.h |
| +++ b/arch/arm64/include/asm/unistd.h |
| @@ -43,7 +43,7 @@ |
| #define __ARM_NR_compat_cacheflush (__ARM_NR_COMPAT_BASE+2) |
| #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE+5) |
| |
| -#define __NR_compat_syscalls 427 |
| +#define __NR_compat_syscalls 440 |
| #endif |
| |
| #define __ARCH_WANT_SYS_CLONE |
| diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h |
| index ba9554572592..27179bd921ff 100644 |
| --- a/arch/arm64/include/asm/unistd32.h |
| +++ b/arch/arm64/include/asm/unistd32.h |
| @@ -863,6 +863,8 @@ __SYSCALL(__NR_sched_rr_get_interval_time64, sys_sched_rr_get_interval) |
| __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) |
| #define __NR_io_uring_enter 426 |
| __SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) |
| +#define __NR_faccessat2 439 |
| +__SYSCALL(__NR_faccessat2, sys_faccessat2) |
| |
| /* |
| * Please add new compat syscalls above this comment and update |
| diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl |
| index b056050a44ba..7455df86745b 100644 |
| --- a/arch/x86/entry/syscalls/syscall_32.tbl |
| +++ b/arch/x86/entry/syscalls/syscall_32.tbl |
| @@ -414,3 +414,4 @@ |
| 423 i386 sched_rr_get_interval_time64 sys_sched_rr_get_interval __ia32_sys_sched_rr_get_interval |
| 425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup |
| 426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter |
| +439 i386 faccessat2 sys_faccessat2 |
| diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl |
| index 9e69bd2fd081..74a44ceb3e94 100644 |
| --- a/arch/x86/entry/syscalls/syscall_64.tbl |
| +++ b/arch/x86/entry/syscalls/syscall_64.tbl |
| @@ -341,6 +341,7 @@ |
| 332 common statx sys_statx |
| 425 common io_uring_setup __x64_sys_io_uring_setup |
| 426 common io_uring_enter __x64_sys_io_uring_enter |
| +439 common faccessat2 sys_faccessat2 |
| |
| # |
| # x32-specific system call numbers start at 512 to avoid cache impact |
| diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h |
| index a78186d826d7..4437b0dc619d 100644 |
| --- a/include/linux/syscalls.h |
| +++ b/include/linux/syscalls.h |
| @@ -809,6 +809,8 @@ asmlinkage long sys_renameat2(int olddfd, const char __user *oldname, |
| asmlinkage long sys_futimesat(int dfd, const char __user *filename, |
| struct timeval __user *utimes); |
| asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode); |
| +asmlinkage long sys_faccessat2(int dfd, const char __user *filename, int mode, |
| + int flags); |
| asmlinkage long sys_fchmodat(int dfd, const char __user * filename, |
| umode_t mode); |
| asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
| diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h |
| index d97d59ebf682..e1c762e2baa6 100644 |
| --- a/include/uapi/asm-generic/unistd.h |
| +++ b/include/uapi/asm-generic/unistd.h |
| @@ -781,8 +781,11 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) |
| #define __NR_io_uring_enter 426 |
| __SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) |
| |
| +#define __NR_faccessat2 439 |
| +__SYSCALL(__NR_faccessat2, sys_faccessat2) |
| + |
| #undef __NR_syscalls |
| -#define __NR_syscalls 427 |
| +#define __NR_syscalls 440 |
| |
| /* |
| * All syscalls below here should go away really, |
| -- |
| 2.31.1 |
| |
