From dc651fe2e6b16087c519c0bd0bf943cb7c53c807 Mon Sep 17 00:00:00 2001 In-Reply-To: <20240423234355.2414567-1-Tony.Ambardar@gmail.com> References: <20240423234355.2414567-1-Tony.Ambardar@gmail.com> From: Tony Ambardar Date: Sat, 20 Apr 2024 21:30:13 -0700 Subject: [PATCH v3] add renameat2 linux syscall wrapper To: musl@lists.openwall.com Cc: Rich Felker This syscall is available since Linux 3.15 and also implemented in glibc from version 2.28. It is commonly used in filesystem or security contexts. Constants RENAME_NOREPLACE, RENAME_EXCHANGE, RENAME_WHITEOUT are guarded by _GNU_SOURCE as with glibc. Signed-off-by: Tony Ambardar --- v2 -> v3: * call SYS_renameat first if applicable * drop unneeded error code handling v1 -> v2: * align related constants * drop 'int' from 'unsigned int' * add fallback to SYS_renameat where applicable --- include/stdio.h | 7 +++++++ src/linux/renameat2.c | 11 +++++++++++ 2 files changed, 18 insertions(+) create mode 100644 src/linux/renameat2.c --- a/include/stdio.h +++ b/include/stdio.h @@ -158,6 +158,13 @@ char *ctermid(char *); #define L_ctermid 20 #endif +#if defined(_GNU_SOURCE) +#define RENAME_NOREPLACE (1 << 0) +#define RENAME_EXCHANGE (1 << 1) +#define RENAME_WHITEOUT (1 << 2) + +int renameat2(int, const char *, int, const char *, unsigned); +#endif #if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \ || defined(_BSD_SOURCE) --- /dev/null +++ b/src/linux/renameat2.c @@ -0,0 +1,11 @@ +#define _GNU_SOURCE +#include +#include "syscall.h" + +int renameat2(int oldfd, const char *old, int newfd, const char *new, unsigned flags) +{ +#ifdef SYS_renameat + if (!flags) return syscall(SYS_renameat, oldfd, old, newfd, new); +#endif + return syscall(SYS_renameat2, oldfd, old, newfd, new, flags); +}