From 9afc5eee65ca7d717a99d6fe8f4adfe32a40940a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 13 Jul 2018 12:52:28 +0200 Subject: y2038: globally rename compat_time to old_time32 Christoph Hellwig suggested a slightly different path for handling backwards compatibility with the 32-bit time_t based system calls: Rather than simply reusing the compat_sys_* entry points on 32-bit architectures unchanged, we get rid of those entry points and the compat_time types by renaming them to something that makes more sense on 32-bit architectures (which don't have a compat mode otherwise), and then share the entry points under the new name with the 64-bit architectures that use them for implementing the compatibility. The following types and interfaces are renamed here, and moved from linux/compat_time.h to linux/time32.h: old new --- --- compat_time_t old_time32_t struct compat_timeval struct old_timeval32 struct compat_timespec struct old_timespec32 struct compat_itimerspec struct old_itimerspec32 ns_to_compat_timeval() ns_to_old_timeval32() get_compat_itimerspec64() get_old_itimerspec32() put_compat_itimerspec64() put_old_itimerspec32() compat_get_timespec64() get_old_timespec32() compat_put_timespec64() put_old_timespec32() As we already have aliases in place, this patch addresses only the instances that are relevant to the system call interface in particular, not those that occur in device drivers and other modules. Those will get handled separately, while providing the 64-bit version of the respective interfaces. I'm not renaming the timex, rusage and itimerval structures, as we are still debating what the new interface will look like, and whether we will need a replacement at all. This also doesn't change the names of the syscall entry points, which can be done more easily when we actually switch over the 32-bit architectures to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix. Suggested-by: Christoph Hellwig Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/ Signed-off-by: Arnd Bergmann --- include/linux/compat.h | 96 +++++++++++++++++++++++++------------------------- 1 file changed, 48 insertions(+), 48 deletions(-) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index 1a3c4f37e908..0e058792ecf6 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -7,7 +7,7 @@ */ #include -#include +#include #include #include /* for HZ */ @@ -116,13 +116,13 @@ struct compat_sel_arg_struct; struct rusage; struct compat_utimbuf { - compat_time_t actime; - compat_time_t modtime; + old_time32_t actime; + old_time32_t modtime; }; struct compat_itimerval { - struct compat_timeval it_interval; - struct compat_timeval it_value; + struct old_timeval32 it_interval; + struct old_timeval32 it_value; }; struct itimerval; @@ -146,7 +146,7 @@ struct compat_timex { compat_long_t constant; compat_long_t precision; compat_long_t tolerance; - struct compat_timeval time; + struct old_timeval32 time; compat_long_t tick; compat_long_t ppsfreq; compat_long_t jitter; @@ -307,8 +307,8 @@ struct compat_rlimit { }; struct compat_rusage { - struct compat_timeval ru_utime; - struct compat_timeval ru_stime; + struct old_timeval32 ru_utime; + struct old_timeval32 ru_stime; compat_long_t ru_maxrss; compat_long_t ru_ixrss; compat_long_t ru_idrss; @@ -457,8 +457,8 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr int get_compat_sigevent(struct sigevent *event, const struct compat_sigevent __user *u_event); -static inline int compat_timeval_compare(struct compat_timeval *lhs, - struct compat_timeval *rhs) +static inline int old_timeval32_compare(struct old_timeval32 *lhs, + struct old_timeval32 *rhs) { if (lhs->tv_sec < rhs->tv_sec) return -1; @@ -467,8 +467,8 @@ static inline int compat_timeval_compare(struct compat_timeval *lhs, return lhs->tv_usec - rhs->tv_usec; } -static inline int compat_timespec_compare(struct compat_timespec *lhs, - struct compat_timespec *rhs) +static inline int old_timespec32_compare(struct old_timespec32 *lhs, + struct old_timespec32 *rhs) { if (lhs->tv_sec < rhs->tv_sec) return -1; @@ -552,12 +552,12 @@ asmlinkage long compat_sys_io_getevents(compat_aio_context_t ctx_id, compat_long_t min_nr, compat_long_t nr, struct io_event __user *events, - struct compat_timespec __user *timeout); + struct old_timespec32 __user *timeout); asmlinkage long compat_sys_io_pgetevents(compat_aio_context_t ctx_id, compat_long_t min_nr, compat_long_t nr, struct io_event __user *events, - struct compat_timespec __user *timeout, + struct old_timespec32 __user *timeout, const struct __compat_aio_sigset __user *usig); /* fs/cookies.c */ @@ -642,11 +642,11 @@ asmlinkage long compat_sys_sendfile64(int out_fd, int in_fd, asmlinkage long compat_sys_pselect6(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp, compat_ulong_t __user *exp, - struct compat_timespec __user *tsp, + struct old_timespec32 __user *tsp, void __user *sig); asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds, unsigned int nfds, - struct compat_timespec __user *tsp, + struct old_timespec32 __user *tsp, const compat_sigset_t __user *sigmask, compat_size_t sigsetsize); @@ -671,15 +671,15 @@ asmlinkage long compat_sys_newfstat(unsigned int fd, /* fs/timerfd.c */ asmlinkage long compat_sys_timerfd_gettime(int ufd, - struct compat_itimerspec __user *otmr); + struct old_itimerspec32 __user *otmr); asmlinkage long compat_sys_timerfd_settime(int ufd, int flags, - const struct compat_itimerspec __user *utmr, - struct compat_itimerspec __user *otmr); + const struct old_itimerspec32 __user *utmr, + struct old_itimerspec32 __user *otmr); /* fs/utimes.c */ asmlinkage long compat_sys_utimensat(unsigned int dfd, const char __user *filename, - struct compat_timespec __user *t, + struct old_timespec32 __user *t, int flags); /* kernel/exit.c */ @@ -691,7 +691,7 @@ asmlinkage long compat_sys_waitid(int, compat_pid_t, /* kernel/futex.c */ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val, - struct compat_timespec __user *utime, u32 __user *uaddr2, + struct old_timespec32 __user *utime, u32 __user *uaddr2, u32 val3); asmlinkage long compat_sys_set_robust_list(struct compat_robust_list_head __user *head, @@ -701,8 +701,8 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, compat_size_t __user *len_ptr); /* kernel/hrtimer.c */ -asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp, - struct compat_timespec __user *rmtp); +asmlinkage long compat_sys_nanosleep(struct old_timespec32 __user *rqtp, + struct old_timespec32 __user *rmtp); /* kernel/itimer.c */ asmlinkage long compat_sys_getitimer(int which, @@ -722,19 +722,19 @@ asmlinkage long compat_sys_timer_create(clockid_t which_clock, struct compat_sigevent __user *timer_event_spec, timer_t __user *created_timer_id); asmlinkage long compat_sys_timer_gettime(timer_t timer_id, - struct compat_itimerspec __user *setting); + struct old_itimerspec32 __user *setting); asmlinkage long compat_sys_timer_settime(timer_t timer_id, int flags, - struct compat_itimerspec __user *new, - struct compat_itimerspec __user *old); + struct old_itimerspec32 __user *new, + struct old_itimerspec32 __user *old); asmlinkage long compat_sys_clock_settime(clockid_t which_clock, - struct compat_timespec __user *tp); + struct old_timespec32 __user *tp); asmlinkage long compat_sys_clock_gettime(clockid_t which_clock, - struct compat_timespec __user *tp); + struct old_timespec32 __user *tp); asmlinkage long compat_sys_clock_getres(clockid_t which_clock, - struct compat_timespec __user *tp); + struct old_timespec32 __user *tp); asmlinkage long compat_sys_clock_nanosleep(clockid_t which_clock, int flags, - struct compat_timespec __user *rqtp, - struct compat_timespec __user *rmtp); + struct old_timespec32 __user *rqtp, + struct old_timespec32 __user *rmtp); /* kernel/ptrace.c */ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, @@ -748,7 +748,7 @@ asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len, compat_ulong_t __user *user_mask_ptr); asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid, - struct compat_timespec __user *interval); + struct old_timespec32 __user *interval); /* kernel/signal.c */ asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr, @@ -768,7 +768,7 @@ asmlinkage long compat_sys_rt_sigpending(compat_sigset_t __user *uset, compat_size_t sigsetsize); asmlinkage long compat_sys_rt_sigtimedwait(compat_sigset_t __user *uthese, struct compat_siginfo __user *uinfo, - struct compat_timespec __user *uts, compat_size_t sigsetsize); + struct old_timespec32 __user *uts, compat_size_t sigsetsize); asmlinkage long compat_sys_rt_sigqueueinfo(compat_pid_t pid, int sig, struct compat_siginfo __user *uinfo); /* No generic prototype for rt_sigreturn */ @@ -782,9 +782,9 @@ asmlinkage long compat_sys_setrlimit(unsigned int resource, asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru); /* kernel/time.c */ -asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv, +asmlinkage long compat_sys_gettimeofday(struct old_timeval32 __user *tv, struct timezone __user *tz); -asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv, +asmlinkage long compat_sys_settimeofday(struct old_timeval32 __user *tv, struct timezone __user *tz); asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp); @@ -798,11 +798,11 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name, asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, compat_size_t msg_len, unsigned int msg_prio, - const struct compat_timespec __user *u_abs_timeout); + const struct old_timespec32 __user *u_abs_timeout); asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, compat_size_t msg_len, unsigned int __user *u_msg_prio, - const struct compat_timespec __user *u_abs_timeout); + const struct old_timespec32 __user *u_abs_timeout); asmlinkage long compat_sys_mq_notify(mqd_t mqdes, const struct compat_sigevent __user *u_notification); asmlinkage long compat_sys_mq_getsetattr(mqd_t mqdes, @@ -819,7 +819,7 @@ asmlinkage long compat_sys_msgsnd(int msqid, compat_uptr_t msgp, /* ipc/sem.c */ asmlinkage long compat_sys_semctl(int semid, int semnum, int cmd, int arg); asmlinkage long compat_sys_semtimedop(int semid, struct sembuf __user *tsems, - unsigned nsems, const struct compat_timespec __user *timeout); + unsigned nsems, const struct old_timespec32 __user *timeout); /* ipc/shm.c */ asmlinkage long compat_sys_shmctl(int first, int second, void __user *uptr); @@ -876,7 +876,7 @@ asmlinkage long compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, struct compat_siginfo __user *uinfo); asmlinkage long compat_sys_recvmmsg(int fd, struct compat_mmsghdr __user *mmsg, unsigned vlen, unsigned int flags, - struct compat_timespec __user *timeout); + struct old_timespec32 __user *timeout); asmlinkage long compat_sys_wait4(compat_pid_t pid, compat_uint_t __user *stat_addr, int options, struct compat_rusage __user *ru); @@ -928,7 +928,7 @@ asmlinkage long compat_sys_pwritev64v2(unsigned long fd, asmlinkage long compat_sys_open(const char __user *filename, int flags, umode_t mode); asmlinkage long compat_sys_utimes(const char __user *filename, - struct compat_timeval __user *t); + struct old_timeval32 __user *t); /* __ARCH_WANT_SYSCALL_NO_FLAGS */ asmlinkage long compat_sys_signalfd(int ufd, @@ -942,15 +942,15 @@ asmlinkage long compat_sys_newlstat(const char __user *filename, struct compat_stat __user *statbuf); /* __ARCH_WANT_SYSCALL_DEPRECATED */ -asmlinkage long compat_sys_time(compat_time_t __user *tloc); +asmlinkage long compat_sys_time(old_time32_t __user *tloc); asmlinkage long compat_sys_utime(const char __user *filename, struct compat_utimbuf __user *t); asmlinkage long compat_sys_futimesat(unsigned int dfd, const char __user *filename, - struct compat_timeval __user *t); + struct old_timeval32 __user *t); asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp, compat_ulong_t __user *exp, - struct compat_timeval __user *tvp); + struct old_timeval32 __user *tvp); asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u32); asmlinkage long compat_sys_recv(int fd, void __user *buf, compat_size_t len, unsigned flags); @@ -983,7 +983,7 @@ asmlinkage long compat_sys_sigaction(int sig, #endif /* obsolete: kernel/time/time.c */ -asmlinkage long compat_sys_stime(compat_time_t __user *tptr); +asmlinkage long compat_sys_stime(old_time32_t __user *tptr); /* obsolete: net/socket.c */ asmlinkage long compat_sys_socketcall(int call, u32 __user *args); @@ -1002,15 +1002,15 @@ static inline bool in_compat_syscall(void) { return is_compat_task(); } #endif /** - * ns_to_compat_timeval - Compat version of ns_to_timeval + * ns_to_old_timeval32 - Compat version of ns_to_timeval * @nsec: the nanoseconds value to be converted * - * Returns the compat_timeval representation of the nsec parameter. + * Returns the old_timeval32 representation of the nsec parameter. */ -static inline struct compat_timeval ns_to_compat_timeval(s64 nsec) +static inline struct old_timeval32 ns_to_old_timeval32(s64 nsec) { struct timeval tv; - struct compat_timeval ctv; + struct old_timeval32 ctv; tv = ns_to_timeval(nsec); ctv.tv_sec = tv.tv_sec; -- cgit v1.2.3 From fb3739759474d150a9927b920a80ea2afb4c2a51 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 18 Apr 2018 22:01:26 +0200 Subject: asm-generic: Move common compat types to asm-generic/compat.h While converting compat system call handlers to work on 32-bit architectures, I found a number of types used in those handlers that are identical between all architectures. Let's move all the identical ones into asm-generic/compat.h to avoid having to add even more identical definitions of those types. For unknown reasons, mips defines __compat_gid32_t, __compat_uid32_t and compat_caddr_t as signed, while all others have them unsigned. This seems to be a mistake, but I'm leaving it alone here. The other types all differ by size or alignment on at least on architecture. compat_aio_context_t is currently defined in linux/compat.h but also needed for compat_sys_io_getevents(), so let's move it into the same place. While we still have not decided whether the 32-bit time handling will always use the compat syscalls, or in which form, I think this is a useful cleanup that we can merge regardless. Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- include/linux/compat.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index 0e058792ecf6..d376fa8be00d 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -110,8 +110,6 @@ typedef struct compat_sigaltstack { typedef __compat_uid32_t compat_uid_t; typedef __compat_gid32_t compat_gid_t; -typedef compat_ulong_t compat_aio_context_t; - struct compat_sel_arg_struct; struct rusage; -- cgit v1.2.3 From 4faea239e529d1d6b3b93fbf08d5e90427961a41 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 17 Apr 2018 12:03:19 +0200 Subject: y2038: utimes: Rework #ifdef guards for compat syscalls After changing over to 64-bit time_t syscalls, many architectures will want compat_sys_utimensat() but not respective handlers for utime(), utimes() and futimesat(). This adds a new __ARCH_WANT_SYS_UTIME32 to complement __ARCH_WANT_SYS_UTIME. For now, all 64-bit architectures that support CONFIG_COMPAT set it, but future 64-bit architectures will not (tile would not have needed it either, but got removed). As older 32-bit architectures get converted to using CONFIG_64BIT_TIME, they will have to use __ARCH_WANT_SYS_UTIME32 instead of __ARCH_WANT_SYS_UTIME. Architectures using the generic syscall ABI don't need either of them as they never had a utime syscall. Since the compat_utimbuf structure is now required outside of CONFIG_COMPAT, I'm moving it into compat_time.h. Signed-off-by: Arnd Bergmann --- changed from last version: - renamed __ARCH_WANT_COMPAT_SYS_UTIME to __ARCH_WANT_SYS_UTIME32 --- include/linux/compat.h | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index d376fa8be00d..6fb5abdb87be 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -113,11 +113,6 @@ typedef __compat_gid32_t compat_gid_t; struct compat_sel_arg_struct; struct rusage; -struct compat_utimbuf { - old_time32_t actime; - old_time32_t modtime; -}; - struct compat_itimerval { struct old_timeval32 it_interval; struct old_timeval32 it_value; @@ -942,7 +937,7 @@ asmlinkage long compat_sys_newlstat(const char __user *filename, /* __ARCH_WANT_SYSCALL_DEPRECATED */ asmlinkage long compat_sys_time(old_time32_t __user *tloc); asmlinkage long compat_sys_utime(const char __user *filename, - struct compat_utimbuf __user *t); + struct old_utimbuf32 __user *t); asmlinkage long compat_sys_futimesat(unsigned int dfd, const char __user *filename, struct old_timeval32 __user *t); -- cgit v1.2.3 From 22839869f21ab3850fbbac9b425ccc4c0023926f Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 5 Sep 2018 15:34:42 +0100 Subject: signal: Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack The sigaltstack(2) system call fails with -ENOMEM if the new alternative signal stack is found to be smaller than SIGMINSTKSZ. On architectures such as arm64, where the native value for SIGMINSTKSZ is larger than the compat value, this can result in an unexpected error being reported to a compat task. See, for example: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904385 This patch fixes the problem by extending do_sigaltstack to take the minimum signal stack size as an additional parameter, allowing the native and compat system call entry code to pass in their respective values. COMPAT_SIGMINSTKSZ is just defined as SIGMINSTKSZ if it has not been defined by the architecture. Cc: Arnd Bergmann Cc: Dominik Brodowski Cc: "Eric W. Biederman" Cc: Andrew Morton Cc: Al Viro Cc: Oleg Nesterov Reported-by: Steve McIntyre Tested-by: Steve McIntyre <93sam@debian.org> Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- include/linux/compat.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index 1a3c4f37e908..de0c13bdcd2c 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -103,6 +103,9 @@ typedef struct compat_sigaltstack { compat_size_t ss_size; } compat_stack_t; #endif +#ifndef COMPAT_MINSIGSTKSZ +#define COMPAT_MINSIGSTKSZ MINSIGSTKSZ +#endif #define compat_jiffies_to_clock_t(x) \ (((unsigned long)(x) * COMPAT_USER_HZ) / HZ) -- cgit v1.2.3 From ae7795bc6187a15ec51cf258abae656a625f9980 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 25 Sep 2018 11:27:20 +0200 Subject: signal: Distinguish between kernel_siginfo and siginfo Linus recently observed that if we did not worry about the padding member in struct siginfo it is only about 48 bytes, and 48 bytes is much nicer than 128 bytes for allocating on the stack and copying around in the kernel. The obvious thing of only adding the padding when userspace is including siginfo.h won't work as there are sigframe definitions in the kernel that embed struct siginfo. So split siginfo in two; kernel_siginfo and siginfo. Keeping the traditional name for the userspace definition. While the version that is used internally to the kernel and ultimately will not be padded to 128 bytes is called kernel_siginfo. The definition of struct kernel_siginfo I have put in include/signal_types.h A set of buildtime checks has been added to verify the two structures have the same field offsets. To make it easy to verify the change kernel_siginfo retains the same size as siginfo. The reduction in size comes in a following change. Signed-off-by: "Eric W. Biederman" --- include/linux/compat.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index 1a3c4f37e908..4565d65b1776 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -452,8 +452,8 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, unsigned long bitmap_size); long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, unsigned long bitmap_size); -int copy_siginfo_from_user32(siginfo_t *to, const struct compat_siginfo __user *from); -int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *from); +int copy_siginfo_from_user32(kernel_siginfo_t *to, const struct compat_siginfo __user *from); +int copy_siginfo_to_user32(struct compat_siginfo __user *to, const kernel_siginfo_t *from); int get_compat_sigevent(struct sigevent *event, const struct compat_sigevent __user *u_event); -- cgit v1.2.3 From 89976005536c47a788bdd6cef5a4e9fef3c0de32 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 30 Oct 2018 15:05:49 -0700 Subject: include/linux/compat.h: mark expected switch fall-throughs In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Link: http://lkml.kernel.org/r/20181013115048.GA3262@embeddedor.com Signed-off-by: Gustavo A. R. Silva Acked-by: Kees Cook Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/compat.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index d30e4dbd4be2..06e77473f175 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -488,8 +488,11 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set, compat_sigset_t v; switch (_NSIG_WORDS) { case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3]; + /* fall through */ case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2]; + /* fall through */ case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1]; + /* fall through */ case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0]; } return copy_to_user(compat, &v, size) ? -EFAULT : 0; -- cgit v1.2.3 From a846446b1914d1e3d996d657754f43fde89bab51 Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Fri, 12 Oct 2018 14:42:52 +0100 Subject: x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT The result of in_compat_syscall() can be pictured as: x86 platform: --------------------------------------------------- | Arch\syscall | 64-bit | ia32 | x32 | |-------------------------------------------------| | x86_64 | false | true | true | |-------------------------------------------------| | i686 | | | | --------------------------------------------------- Other platforms: ------------------------------------------- | Arch\syscall | 64-bit | compat | |-----------------------------------------| | 64-bit | false | true | |-----------------------------------------| | 32-bit(?) | | | ------------------------------------------- As seen, the result of in_compat_syscall() on generic 32-bit platform differs from i686. There is no reason for in_compat_syscall() == true on native i686. It also easy to misread code if the result on native 32-bit platform differs between arches. Because of that non arch-specific code has many places with: if (IS_ENABLED(CONFIG_COMPAT) && in_compat_syscall()) in different variations. It looks-like the only non-x86 code which uses in_compat_syscall() not under CONFIG_COMPAT guard is in amd/amdkfd. But according to the commit a18069c132cb ("amdkfd: Disable support for 32-bit user processes"), it actually should be disabled on native i686. Rename in_compat_syscall() to in_32bit_syscall() for x86-specific code and make in_compat_syscall() false under !CONFIG_COMPAT. A follow on patch will clean up generic users which were forced to check IS_ENABLED(CONFIG_COMPAT) with in_compat_syscall(). Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Reviewed-by: Andy Lutomirski Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Ard Biesheuvel Cc: "David S. Miller" Cc: Herbert Xu Cc: "H. Peter Anvin" Cc: John Stultz Cc: "Kirill A. Shutemov" Cc: Oleg Nesterov Cc: Steffen Klassert Cc: Stephen Boyd Cc: Steven Rostedt Cc: linux-efi@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lkml.kernel.org/r/20181012134253.23266-2-dima@arista.com --- include/linux/compat.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index d30e4dbd4be2..f1ef24c68fcc 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -1029,9 +1029,9 @@ int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, #else /* !CONFIG_COMPAT */ #define is_compat_task() (0) -#ifndef in_compat_syscall +/* Ensure no one redefines in_compat_syscall() under !CONFIG_COMPAT */ +#define in_compat_syscall in_compat_syscall static inline bool in_compat_syscall(void) { return false; } -#endif #endif /* CONFIG_COMPAT */ -- cgit v1.2.3