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authorCatalin Marinas <catalin.marinas@arm.com>2012-03-05 06:49:31 -0500
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 08:42:08 -0400
commit7992d60dc46576bc6f6429d87f313462141db6d2 (patch)
tree2527b2d32e1d9be67c9c9b63a413cdf28406bf4a /arch/arm64/kernel/sys.c
parentf668cd1673aa2e645ae98b65c4ffb9dae2c9ac17 (diff)
arm64: System calls handling
This patch adds support for system calls coming from 64-bit applications. It uses the asm-generic/unistd.h definitions with the canonical set of system calls. The private system calls are only used for 32-bit (compat) applications as 64-bit ones can set the TLS and flush the caches entirely from user space. The sys_call_table is just an array defined in a C file and it contains pointers to the syscall functions. The array is 4KB aligned to allow the use of the ADRP instruction (longer range ADR) in entry.S. 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>
Diffstat (limited to 'arch/arm64/kernel/sys.c')
-rw-r--r--arch/arm64/kernel/sys.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
new file mode 100644
index 000000000000..905fcfb0ddd0
--- /dev/null
+++ b/arch/arm64/kernel/sys.c
@@ -0,0 +1,138 @@
1/*
2 * AArch64-specific system calls implementation
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author: Catalin Marinas <catalin.marinas@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/compiler.h>
21#include <linux/errno.h>
22#include <linux/fs.h>
23#include <linux/mm.h>
24#include <linux/export.h>
25#include <linux/sched.h>
26#include <linux/slab.h>
27#include <linux/syscalls.h>
28
29/*
30 * Clone a task - this clones the calling program thread.
31 */
32asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
33 int __user *parent_tidptr, unsigned long tls_val,
34 int __user *child_tidptr, struct pt_regs *regs)
35{
36 if (!newsp)
37 newsp = regs->sp;
38 /* 16-byte aligned stack mandatory on AArch64 */
39 if (newsp & 15)
40 return -EINVAL;
41 return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
42}
43
44/*
45 * sys_execve() executes a new program.
46 */
47asmlinkage long sys_execve(const char __user *filenamei,
48 const char __user *const __user *argv,
49 const char __user *const __user *envp,
50 struct pt_regs *regs)
51{
52 long error;
53 char * filename;
54
55 filename = getname(filenamei);
56 error = PTR_ERR(filename);
57 if (IS_ERR(filename))
58 goto out;
59 error = do_execve(filename, argv, envp, regs);
60 putname(filename);
61out:
62 return error;
63}
64
65int kernel_execve(const char *filename,
66 const char *const argv[],
67 const char *const envp[])
68{
69 struct pt_regs regs;
70 int ret;
71
72 memset(&regs, 0, sizeof(struct pt_regs));
73 ret = do_execve(filename,
74 (const char __user *const __user *)argv,
75 (const char __user *const __user *)envp, &regs);
76 if (ret < 0)
77 goto out;
78
79 /*
80 * Save argc to the register structure for userspace.
81 */
82 regs.regs[0] = ret;
83
84 /*
85 * We were successful. We won't be returning to our caller, but
86 * instead to user space by manipulating the kernel stack.
87 */
88 asm( "add x0, %0, %1\n\t"
89 "mov x1, %2\n\t"
90 "mov x2, %3\n\t"
91 "bl memmove\n\t" /* copy regs to top of stack */
92 "mov x27, #0\n\t" /* not a syscall */
93 "mov x28, %0\n\t" /* thread structure */
94 "mov sp, x0\n\t" /* reposition stack pointer */
95 "b ret_to_user"
96 :
97 : "r" (current_thread_info()),
98 "Ir" (THREAD_START_SP - sizeof(regs)),
99 "r" (&regs),
100 "Ir" (sizeof(regs))
101 : "x0", "x1", "x2", "x27", "x28", "x30", "memory");
102
103 out:
104 return ret;
105}
106EXPORT_SYMBOL(kernel_execve);
107
108asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
109 unsigned long prot, unsigned long flags,
110 unsigned long fd, off_t off)
111{
112 if (offset_in_page(off) != 0)
113 return -EINVAL;
114
115 return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
116}
117
118/*
119 * Wrappers to pass the pt_regs argument.
120 */
121#define sys_execve sys_execve_wrapper
122#define sys_clone sys_clone_wrapper
123#define sys_rt_sigreturn sys_rt_sigreturn_wrapper
124#define sys_sigaltstack sys_sigaltstack_wrapper
125
126#include <asm/syscalls.h>
127
128#undef __SYSCALL
129#define __SYSCALL(nr, sym) [nr] = sym,
130
131/*
132 * The sys_call_table array must be 4K aligned to be accessible from
133 * kernel/entry.S.
134 */
135void *sys_call_table[__NR_syscalls] __aligned(4096) = {
136 [0 ... __NR_syscalls - 1] = sys_ni_syscall,
137#include <asm/unistd.h>
138};
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