/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_HIGHUID_H #define _LINUX_HIGHUID_H #include <linux/types.h> /* * general notes: * * CONFIG_UID16 is defined if the given architecture needs to * support backwards compatibility for old system calls. * * kernel code should use uid_t and gid_t at all times when dealing with * kernel-private data. * * old_uid_t and old_gid_t should only be different if CONFIG_UID16 is * defined, else the platform should provide dummy typedefs for them * such that they are equivalent to __kernel_{u,g}id_t. * * uid16_t and gid16_t are used on all architectures. (when dealing * with structures hard coded to 16 bits, such as in filesystems) */ /* * This is the "overflow" UID and GID. They are used to signify uid/gid * overflow to old programs when they request uid/gid information but are * using the old 16 bit interfaces. * When you run a libc5 program, it will think that all highuid files or * processes are owned by this uid/gid. * The idea is that it's better to do so than possibly return 0 in lieu of * 65536, etc. */ extern int overflowuid; extern int overflowgid; extern void __bad_uid(void); extern void __bad_gid(void); #define DEFAULT_OVERFLOWUID … #define DEFAULT_OVERFLOWGID … #ifdef CONFIG_UID16 /* prevent uid mod 65536 effect by returning a default value for high UIDs */ #define high2lowuid(uid) … #define high2lowgid(gid) … /* * -1 is different in 16 bits than it is in 32 bits * these macros are used by chown(), setreuid(), ..., */ #define low2highuid(uid) … #define low2highgid(gid) … #define __convert_uid(size, uid) … #define __convert_gid(size, gid) … #else #define __convert_uid … #define __convert_gid … #endif /* !CONFIG_UID16 */ /* uid/gid input should be always 32bit uid_t */ #define SET_UID(var, uid) … #define SET_GID(var, gid) … /* * Everything below this line is needed on all architectures, to deal with * filesystems that only store 16 bits of the UID/GID, etc. */ /* * This is the UID and GID that will get written to disk if a filesystem * only supports 16-bit UIDs and the kernel has a high UID/GID to write */ extern int fs_overflowuid; extern int fs_overflowgid; #define DEFAULT_FS_OVERFLOWUID … #define DEFAULT_FS_OVERFLOWGID … /* * Since these macros are used in architectures that only need limited * 16-bit UID back compatibility, we won't use old_uid_t and old_gid_t */ #define fs_high2lowuid(uid) … #define fs_high2lowgid(gid) … #define low_16_bits(x) … #define high_16_bits(x) … #endif /* _LINUX_HIGHUID_H */
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