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arm64: Implement the compat_sys_call_table in C 

Unlike the sys_call_table[], the compat one was implemented in sys32.S
making it impossible to notice discrepancies between the number of
compat syscalls and the __NR_compat_syscalls macro, the latter having to
be defined in asm/unistd.h as including asm/unistd32.h would cause
conflicts on __NR_* definitions. With this patch, incorrect
__NR_compat_syscalls values will result in a build-time error.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
hifive-unleashed-5.1
Catalin Marinas 2015-01-06 16:42:32 +00:00
parent 54e45c169d
commit 0156411b18
5 changed files with 68 additions and 24 deletions
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3
arch/arm64/include/asm/unistd.h
View File

@ -48,6 +48,9 @@
#endif
#define __ARCH_WANT_SYS_CLONE
#ifndef __COMPAT_SYSCALL_NR
#include <uapi/asm/unistd.h>
#endif
#define NR_syscalls (__NR_syscalls)

2
arch/arm64/kernel/Makefile
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@ -19,7 +19,7 @@ arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
cpuinfo.o cpu_errata.o alternative.o cacheinfo.o
arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o \
sys_compat.o entry32.o \
../../arm/kernel/opcodes.o
arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o
arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o

2
arch/arm64/kernel/entry.S
View File

@ -433,7 +433,7 @@ el0_svc_compat:
/*
* AArch32 syscall handling
*/
adr stbl, compat_sys_call_table // load compat syscall table pointer
adrp stbl, compat_sys_call_table // load compat syscall table pointer
uxtw scno, w7 // syscall number in w7 (r7)
mov sc_nr, #__NR_compat_syscalls
b el0_svc_naked

34
arch/arm64/kernel/sys32.S → arch/arm64/kernel/entry32.S
View File

@ -27,26 +27,26 @@
* System call wrappers for the AArch32 compatibility layer.
*/
compat_sys_sigreturn_wrapper:
ENTRY(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:
ENTRY(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_statfs64_wrapper:
ENTRY(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:
ENTRY(compat_sys_fstatfs64_wrapper)
mov w3, #84
cmp w1, #88
csel w1, w3, w1, eq
@ -58,33 +58,33 @@ ENDPROC(compat_sys_fstatfs64_wrapper)
* in registers or that take 32-bit parameters which require sign
* extension.
*/
compat_sys_pread64_wrapper:
ENTRY(compat_sys_pread64_wrapper)
regs_to_64 x3, x4, x5
b sys_pread64
ENDPROC(compat_sys_pread64_wrapper)
compat_sys_pwrite64_wrapper:
ENTRY(compat_sys_pwrite64_wrapper)
regs_to_64 x3, x4, x5
b sys_pwrite64
ENDPROC(compat_sys_pwrite64_wrapper)
compat_sys_truncate64_wrapper:
ENTRY(compat_sys_truncate64_wrapper)
regs_to_64 x1, x2, x3
b sys_truncate
ENDPROC(compat_sys_truncate64_wrapper)
compat_sys_ftruncate64_wrapper:
ENTRY(compat_sys_ftruncate64_wrapper)
regs_to_64 x1, x2, x3
b sys_ftruncate
ENDPROC(compat_sys_ftruncate64_wrapper)
compat_sys_readahead_wrapper:
ENTRY(compat_sys_readahead_wrapper)
regs_to_64 x1, x2, x3
mov w2, w4
b sys_readahead
ENDPROC(compat_sys_readahead_wrapper)
compat_sys_fadvise64_64_wrapper:
ENTRY(compat_sys_fadvise64_64_wrapper)
mov w6, w1
regs_to_64 x1, x2, x3
regs_to_64 x2, x4, x5
@ -92,24 +92,14 @@ compat_sys_fadvise64_64_wrapper:
b sys_fadvise64_64
ENDPROC(compat_sys_fadvise64_64_wrapper)
compat_sys_sync_file_range2_wrapper:
ENTRY(compat_sys_sync_file_range2_wrapper)
regs_to_64 x2, x2, x3
regs_to_64 x3, x4, x5
b sys_sync_file_range2
ENDPROC(compat_sys_sync_file_range2_wrapper)
compat_sys_fallocate_wrapper:
ENTRY(compat_sys_fallocate_wrapper)
regs_to_64 x2, x2, x3
regs_to_64 x3, x4, x5
b sys_fallocate
ENDPROC(compat_sys_fallocate_wrapper)
#undef __SYSCALL
#define __SYSCALL(x, y) .quad y // x
/*
* The system calls table must be 4KB aligned.
*/
.align 12
ENTRY(compat_sys_call_table)
#include <asm/unistd32.h>

51
arch/arm64/kernel/sys32.c 100644
View File

@ -0,0 +1,51 @@
/*
* arch/arm64/kernel/sys32.c
*
* Copyright (C) 2015 ARM Ltd.
*
* This program is free software(void); 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(void);//www.gnu.org/licenses/>.
*/
/*
* Needed to avoid conflicting __NR_* macros between uapi/asm/unistd.h and
* asm/unistd32.h.
*/
#define __COMPAT_SYSCALL_NR
#include <linux/compiler.h>
#include <linux/syscalls.h>
asmlinkage long compat_sys_sigreturn_wrapper(void);
asmlinkage long compat_sys_rt_sigreturn_wrapper(void);
asmlinkage long compat_sys_statfs64_wrapper(void);
asmlinkage long compat_sys_fstatfs64_wrapper(void);
asmlinkage long compat_sys_pread64_wrapper(void);
asmlinkage long compat_sys_pwrite64_wrapper(void);
asmlinkage long compat_sys_truncate64_wrapper(void);
asmlinkage long compat_sys_ftruncate64_wrapper(void);
asmlinkage long compat_sys_readahead_wrapper(void);
asmlinkage long compat_sys_fadvise64_64_wrapper(void);
asmlinkage long compat_sys_sync_file_range2_wrapper(void);
asmlinkage long compat_sys_fallocate_wrapper(void);
#undef __SYSCALL
#define __SYSCALL(nr, sym) [nr] = sym,
/*
* The sys_call_table array must be 4K aligned to be accessible from
* kernel/entry.S.
*/
void * const compat_sys_call_table[__NR_compat_syscalls] __aligned(4096) = {
[0 ... __NR_compat_syscalls - 1] = sys_ni_syscall,
#include <asm/unistd32.h>
};