Using this helper allows us to avoid the in-kernel call to the sys_personality() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_personality().
Since ksys_personality is trivial, it is implemented directly in <linux/syscalls.h>, as we do for ksys_close() and friends. This helper is necessary to enable conversion of arm64's syscall handling to use pt_regs wrappers. Signed-off-by: Mark Rutland <[email protected]> Cc: Al Viro <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dave Martin <[email protected]> Cc: Dominik Brodowski <[email protected]> --- include/linux/syscalls.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 70fcda1a9049..652e166deb64 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -79,6 +79,7 @@ union bpf_attr; #include <linux/unistd.h> #include <linux/quota.h> #include <linux/key.h> +#include <linux/personality.h> #include <trace/syscall.h> #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER @@ -1268,4 +1269,14 @@ static inline long ksys_truncate(const char __user *pathname, loff_t length) return do_sys_truncate(pathname, length); } +static inline unsigned int ksys_personality(unsigned int personality) +{ + unsigned int old = current->personality; + + if (personality != 0xffffffff) + set_personality(personality); + + return old; +} + #endif -- 2.11.0
