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authorMickaël Salaün <mic@digikod.net>2015-12-29 15:35:46 -0500
committerRichard Weinberger <richard@nod.at>2016-01-10 15:49:49 -0500
commitd8f8b8445648c267a24f30a72533e77cb6543f21 (patch)
tree771077fdccf7ec1b8b1f09324210867796a52dcd
parent4a0b88070406323487bad730d8945f482151a145 (diff)
um: Add full asm/syscall.h support
Add subarchitecture-independent implementation of asm-generic/syscall.h allowing access to user system call parameters and results: * syscall_get_nr() * syscall_rollback() * syscall_get_error() * syscall_get_return_value() * syscall_set_return_value() * syscall_get_arguments() * syscall_set_arguments() * syscall_get_arch() provided by arch/x86/um/asm/syscall.h This provides the necessary syscall helpers needed by HAVE_ARCH_SECCOMP_FILTER plus syscall_get_error(). This is inspired from Meredydd Luff's patch (https://gerrit.chromium.org/gerrit/21425). Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: David Drysdale <drysdale@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Kees Cook <keescook@chromium.org>
Diffstat
-rw-r--r--arch/um/include/asm/syscall-generic.h138
-rw-r--r--arch/x86/um/asm/syscall.h1
2 files changed, 139 insertions, 0 deletions
diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h
new file mode 100644
index 000000000000..9fb9cf8cd39a
--- /dev/null
+++ b/arch/um/include/asm/syscall-generic.h
@@ -0,0 +1,138 @@
1/*
2 * Access to user system call parameters and results
3 *
4 * See asm-generic/syscall.h for function descriptions.
5 *
6 * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#ifndef __UM_SYSCALL_GENERIC_H
14#define __UM_SYSCALL_GENERIC_H
15
16#include <asm/ptrace.h>
17#include <linux/err.h>
18#include <linux/sched.h>
19#include <sysdep/ptrace.h>
20
21static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
22{
23
24 return PT_REGS_SYSCALL_NR(regs);
25}
26
27static inline void syscall_rollback(struct task_struct *task,
28 struct pt_regs *regs)
29{
30 /* do nothing */
31}
32
33static inline long syscall_get_error(struct task_struct *task,
34 struct pt_regs *regs)
35{
36 const long error = regs_return_value(regs);
37
38 return IS_ERR_VALUE(error) ? error : 0;
39}
40
41static inline long syscall_get_return_value(struct task_struct *task,
42 struct pt_regs *regs)
43{
44 return regs_return_value(regs);
45}
46
47static inline void syscall_set_return_value(struct task_struct *task,
48 struct pt_regs *regs,
49 int error, long val)
50{
51 PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val);
52}
53
54static inline void syscall_get_arguments(struct task_struct *task,
55 struct pt_regs *regs,
56 unsigned int i, unsigned int n,
57 unsigned long *args)
58{
59 const struct uml_pt_regs *r = &regs->regs;
60
61 switch (i) {
62 case 0:
63 if (!n--)
64 break;
65 *args++ = UPT_SYSCALL_ARG1(r);
66 case 1:
67 if (!n--)
68 break;
69 *args++ = UPT_SYSCALL_ARG2(r);
70 case 2:
71 if (!n--)
72 break;
73 *args++ = UPT_SYSCALL_ARG3(r);
74 case 3:
75 if (!n--)
76 break;
77 *args++ = UPT_SYSCALL_ARG4(r);
78 case 4:
79 if (!n--)
80 break;
81 *args++ = UPT_SYSCALL_ARG5(r);
82 case 5:
83 if (!n--)
84 break;
85 *args++ = UPT_SYSCALL_ARG6(r);
86 case 6:
87 if (!n--)
88 break;
89 default:
90 BUG();
91 break;
92 }
93}
94
95static inline void syscall_set_arguments(struct task_struct *task,
96 struct pt_regs *regs,
97 unsigned int i, unsigned int n,
98 const unsigned long *args)
99{
100 struct uml_pt_regs *r = &regs->regs;
101
102 switch (i) {
103 case 0:
104 if (!n--)
105 break;
106 UPT_SYSCALL_ARG1(r) = *args++;
107 case 1:
108 if (!n--)
109 break;
110 UPT_SYSCALL_ARG2(r) = *args++;
111 case 2:
112 if (!n--)
113 break;
114 UPT_SYSCALL_ARG3(r) = *args++;
115 case 3:
116 if (!n--)
117 break;
118 UPT_SYSCALL_ARG4(r) = *args++;
119 case 4:
120 if (!n--)
121 break;
122 UPT_SYSCALL_ARG5(r) = *args++;
123 case 5:
124 if (!n--)
125 break;
126 UPT_SYSCALL_ARG6(r) = *args++;
127 case 6:
128 if (!n--)
129 break;
130 default:
131 BUG();
132 break;
133 }
134}
135
136/* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
137
138#endif /* __UM_SYSCALL_GENERIC_H */
diff --git a/arch/x86/um/asm/syscall.h b/arch/x86/um/asm/syscall.h
index 81d6562ce01d..11ab90dc5f14 100644
--- a/arch/x86/um/asm/syscall.h
+++ b/arch/x86/um/asm/syscall.h
@@ -1,6 +1,7 @@
1#ifndef __UM_ASM_SYSCALL_H 1#ifndef __UM_ASM_SYSCALL_H
2#define __UM_ASM_SYSCALL_H 2#define __UM_ASM_SYSCALL_H
3 3
4#include <asm/syscall-generic.h>
4#include <uapi/linux/audit.h> 5#include <uapi/linux/audit.h>
5 6
6typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long, 7typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-14 20:49:54 -0400