arm64: 32-bit (compat) applications support

This patch adds support for 32-bit applications. The vectors page is a
binary blob mapped into the application user space at 0xffff0000 (the
AArch64 toolchain does not support compilation of AArch32 code). Full
compatibility with ARMv7 user space is supported. The use of deprecated
ARMv7 functionality (SWP, CP15 barriers) has been disabled by default on
AArch64 kernels and unaligned LDM/STM is not supported.

Please note that only the ARM 32-bit EABI is supported, so no OABI
compatibility.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

1 files changed, 282 insertions, 0 deletions

diff --git a/arch/arm64/kernel/sys32.S b/arch/arm64/kernel/sys32.S
new file mode 100644
index 000000000000..5e4dc93cc31f
--- /dev/null
+++ b/arch/arm64/kernel/sys32.S
@@ -0,0 +1,282 @@
+/*
+ * Compat system call wrappers
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Authors: Will Deacon <will.deacon@arm.com>
+ *          Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * System call wrappers for the AArch32 compatibility layer.
+ */
+compat_sys_fork_wrapper:
+        mov     x0, sp
+        b       compat_sys_fork
+ENDPROC(compat_sys_fork_wrapper)
+
+compat_sys_vfork_wrapper:
+        mov     x0, sp
+        b       compat_sys_vfork
+ENDPROC(compat_sys_vfork_wrapper)
+
+compat_sys_execve_wrapper:
+        mov     x3, sp
+        b       compat_sys_execve
+ENDPROC(compat_sys_execve_wrapper)
+
+compat_sys_clone_wrapper:
+        mov     x5, sp
+        b       compat_sys_clone
+ENDPROC(compat_sys_clone_wrapper)
+
+compat_sys_sigreturn_wrapper:
+        mov     x0, sp
+        mov     x27, #0         // prevent syscall restart handling (why)
+        b       compat_sys_sigreturn
+ENDPROC(compat_sys_sigreturn_wrapper)
+
+compat_sys_rt_sigreturn_wrapper:
+        mov     x0, sp
+        mov     x27, #0         // prevent syscall restart handling (why)
+        b       compat_sys_rt_sigreturn
+ENDPROC(compat_sys_rt_sigreturn_wrapper)
+
+compat_sys_sigaltstack_wrapper:
+        ldr     x2, [sp, #S_COMPAT_SP]
+        b       compat_do_sigaltstack
+ENDPROC(compat_sys_sigaltstack_wrapper)
+
+compat_sys_statfs64_wrapper:
+        mov     w3, #84
+        cmp     w1, #88
+        csel    w1, w3, w1, eq
+        b       compat_sys_statfs64
+ENDPROC(compat_sys_statfs64_wrapper)
+
+compat_sys_fstatfs64_wrapper:
+        mov     w3, #84
+        cmp     w1, #88
+        csel    w1, w3, w1, eq
+        b       compat_sys_fstatfs64
+ENDPROC(compat_sys_fstatfs64_wrapper)
+
+/*
+ * Wrappers for AArch32 syscalls that either take 64-bit parameters
+ * in registers or that take 32-bit parameters which require sign
+ * extension.
+ */
+compat_sys_lseek_wrapper:
+        sxtw    x1, w1
+        b       sys_lseek
+ENDPROC(compat_sys_lseek_wrapper)
+
+compat_sys_pread64_wrapper:
+        orr     x3, x4, x5, lsl #32
+        b       sys_pread64
+ENDPROC(compat_sys_pread64_wrapper)
+
+compat_sys_pwrite64_wrapper:
+        orr     x3, x4, x5, lsl #32
+        b       sys_pwrite64
+ENDPROC(compat_sys_pwrite64_wrapper)
+
+compat_sys_truncate64_wrapper:
+        orr     x1, x2, x3, lsl #32
+        b       sys_truncate
+ENDPROC(compat_sys_truncate64_wrapper)
+
+compat_sys_ftruncate64_wrapper:
+        orr     x1, x2, x3, lsl #32
+        b       sys_ftruncate
+ENDPROC(compat_sys_ftruncate64_wrapper)
+
+compat_sys_readahead_wrapper:
+        orr     x1, x2, x3, lsl #32
+        mov     w2, w4
+        b       sys_readahead
+ENDPROC(compat_sys_readahead_wrapper)
+
+compat_sys_lookup_dcookie:
+        orr     x0, x0, x1, lsl #32
+        mov     w1, w2
+        mov     w2, w3
+        b       sys_lookup_dcookie
+ENDPROC(compat_sys_lookup_dcookie)
+
+compat_sys_fadvise64_64_wrapper:
+        mov     w6, w1
+        orr     x1, x2, x3, lsl #32
+        orr     x2, x4, x5, lsl #32
+        mov     w3, w6
+        b       sys_fadvise64_64
+ENDPROC(compat_sys_fadvise64_64_wrapper)
+
+compat_sys_sync_file_range2_wrapper:
+        orr     x2, x2, x3, lsl #32
+        orr     x3, x4, x5, lsl #32
+        b       sys_sync_file_range2
+ENDPROC(compat_sys_sync_file_range2_wrapper)
+
+compat_sys_fallocate_wrapper:
+        orr     x2, x2, x3, lsl #32
+        orr     x3, x4, x5, lsl #32
+        b       sys_fallocate
+ENDPROC(compat_sys_fallocate_wrapper)
+
+compat_sys_fanotify_mark_wrapper:
+        orr     x2, x2, x3, lsl #32
+        mov     w3, w4
+        mov     w4, w5
+        b       sys_fanotify_mark
+ENDPROC(compat_sys_fanotify_mark_wrapper)
+
+/*
+ * Use the compat system call wrappers.
+ */
+#define sys_fork                compat_sys_fork_wrapper
+#define sys_open                compat_sys_open
+#define sys_execve              compat_sys_execve_wrapper
+#define sys_lseek               compat_sys_lseek_wrapper
+#define sys_mount               compat_sys_mount
+#define sys_ptrace              compat_sys_ptrace
+#define sys_times               compat_sys_times
+#define sys_ioctl               compat_sys_ioctl
+#define sys_fcntl               compat_sys_fcntl
+#define sys_ustat               compat_sys_ustat
+#define sys_sigaction           compat_sys_sigaction
+#define sys_sigsuspend          compat_sys_sigsuspend
+#define sys_sigpending          compat_sys_sigpending
+#define sys_setrlimit           compat_sys_setrlimit
+#define sys_getrusage           compat_sys_getrusage
+#define sys_gettimeofday        compat_sys_gettimeofday
+#define sys_settimeofday        compat_sys_settimeofday
+#define sys_statfs              compat_sys_statfs
+#define sys_fstatfs             compat_sys_fstatfs
+#define sys_setitimer           compat_sys_setitimer
+#define sys_getitimer           compat_sys_getitimer
+#define sys_newstat             compat_sys_newstat
+#define sys_newlstat            compat_sys_newlstat
+#define sys_newfstat            compat_sys_newfstat
+#define sys_wait4               compat_sys_wait4
+#define sys_sysinfo             compat_sys_sysinfo
+#define sys_sigreturn           compat_sys_sigreturn_wrapper
+#define sys_clone               compat_sys_clone_wrapper
+#define sys_adjtimex            compat_sys_adjtimex
+#define sys_sigprocmask         compat_sys_sigprocmask
+#define sys_getdents            compat_sys_getdents
+#define sys_select              compat_sys_select
+#define sys_readv               compat_sys_readv
+#define sys_writev              compat_sys_writev
+#define sys_sysctl              compat_sys_sysctl
+#define sys_sched_rr_get_interval compat_sys_sched_rr_get_interval
+#define sys_nanosleep           compat_sys_nanosleep
+#define sys_rt_sigreturn        compat_sys_rt_sigreturn_wrapper
+#define sys_rt_sigaction        compat_sys_rt_sigaction
+#define sys_rt_sigprocmask      compat_sys_rt_sigprocmask
+#define sys_rt_sigpending       compat_sys_rt_sigpending
+#define sys_rt_sigtimedwait     compat_sys_rt_sigtimedwait
+#define sys_rt_sigqueueinfo     compat_sys_rt_sigqueueinfo
+#define sys_rt_sigsuspend       compat_sys_rt_sigsuspend
+#define sys_pread64             compat_sys_pread64_wrapper
+#define sys_pwrite64            compat_sys_pwrite64_wrapper
+#define sys_sigaltstack         compat_sys_sigaltstack_wrapper
+#define sys_sendfile            compat_sys_sendfile
+#define sys_vfork               compat_sys_vfork_wrapper
+#define sys_getrlimit           compat_sys_getrlimit
+#define sys_mmap2               sys_mmap_pgoff
+#define sys_truncate64          compat_sys_truncate64_wrapper
+#define sys_ftruncate64         compat_sys_ftruncate64_wrapper
+#define sys_getdents64          compat_sys_getdents64
+#define sys_fcntl64             compat_sys_fcntl64
+#define sys_readahead           compat_sys_readahead_wrapper
+#define sys_futex               compat_sys_futex
+#define sys_sched_setaffinity   compat_sys_sched_setaffinity
+#define sys_sched_getaffinity   compat_sys_sched_getaffinity
+#define sys_io_setup            compat_sys_io_setup
+#define sys_io_getevents        compat_sys_io_getevents
+#define sys_io_submit           compat_sys_io_submit
+#define sys_lookup_dcookie      compat_sys_lookup_dcookie
+#define sys_timer_create        compat_sys_timer_create
+#define sys_timer_settime       compat_sys_timer_settime
+#define sys_timer_gettime       compat_sys_timer_gettime
+#define sys_clock_settime       compat_sys_clock_settime
+#define sys_clock_gettime       compat_sys_clock_gettime
+#define sys_clock_getres        compat_sys_clock_getres
+#define sys_clock_nanosleep     compat_sys_clock_nanosleep
+#define sys_statfs64            compat_sys_statfs64_wrapper
+#define sys_fstatfs64           compat_sys_fstatfs64_wrapper
+#define sys_utimes              compat_sys_utimes
+#define sys_fadvise64_64        compat_sys_fadvise64_64_wrapper
+#define sys_mq_open             compat_sys_mq_open
+#define sys_mq_timedsend        compat_sys_mq_timedsend
+#define sys_mq_timedreceive     compat_sys_mq_timedreceive
+#define sys_mq_notify           compat_sys_mq_notify
+#define sys_mq_getsetattr       compat_sys_mq_getsetattr
+#define sys_waitid              compat_sys_waitid
+#define sys_recv                compat_sys_recv
+#define sys_recvfrom            compat_sys_recvfrom
+#define sys_setsockopt          compat_sys_setsockopt
+#define sys_getsockopt          compat_sys_getsockopt
+#define sys_sendmsg             compat_sys_sendmsg
+#define sys_recvmsg             compat_sys_recvmsg
+#define sys_semctl              compat_sys_semctl
+#define sys_msgsnd              compat_sys_msgsnd
+#define sys_msgrcv              compat_sys_msgrcv
+#define sys_msgctl              compat_sys_msgctl
+#define sys_shmat               compat_sys_shmat
+#define sys_shmctl              compat_sys_shmctl
+#define sys_keyctl              compat_sys_keyctl
+#define sys_semtimedop          compat_sys_semtimedop
+#define sys_mbind               compat_sys_mbind
+#define sys_get_mempolicy       compat_sys_get_mempolicy
+#define sys_set_mempolicy       compat_sys_set_mempolicy
+#define sys_openat              compat_sys_openat
+#define sys_futimesat           compat_sys_futimesat
+#define sys_pselect6            compat_sys_pselect6
+#define sys_ppoll               compat_sys_ppoll
+#define sys_set_robust_list     compat_sys_set_robust_list
+#define sys_get_robust_list     compat_sys_get_robust_list
+#define sys_sync_file_range2    compat_sys_sync_file_range2_wrapper
+#define sys_vmsplice            compat_sys_vmsplice
+#define sys_move_pages          compat_sys_move_pages
+#define sys_epoll_pwait         compat_sys_epoll_pwait
+#define sys_kexec_load          compat_sys_kexec_load
+#define sys_utimensat           compat_sys_utimensat
+#define sys_signalfd            compat_sys_signalfd
+#define sys_fallocate           compat_sys_fallocate_wrapper
+#define sys_timerfd_settime     compat_sys_timerfd_settime
+#define sys_timerfd_gettime     compat_sys_timerfd_gettime
+#define sys_signalfd4           compat_sys_signalfd4
+#define sys_preadv              compat_sys_preadv
+#define sys_pwritev             compat_sys_pwritev
+#define sys_rt_tgsigqueueinfo   compat_sys_rt_tgsigqueueinfo
+#define sys_recvmmsg            compat_sys_recvmmsg
+#define sys_fanotify_mark       compat_sys_fanotify_mark_wrapper
+
+#undef __SYSCALL
+#define __SYSCALL(x, y)         .quad   y       // x
+#define __SYSCALL_COMPAT
+
+/*
+ * The system calls table must be 4KB aligned.
+ */
+        .align  12
+ENTRY(compat_sys_call_table)
+#include <asm/unistd.h>