1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
#include <stdlib.h>
#include <sys/ptrace.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <linux/elf.h>
#include <compel/plugins/std/syscall-codes.h>
#include "common/page.h"
#include "uapi/compel/asm/infect-types.h"
#include "log.h"
#include "errno.h"
#include "infect.h"
#include "infect-priv.h"
unsigned __page_size = 0;
unsigned __page_shift = 0;
/*
* Injected syscall instruction
*/
const char code_syscall[] = {
0x01, 0x00, 0x00, 0xd4, /* SVC #0 */
0x00, 0x00, 0x20, 0xd4 /* BRK #0 */
};
static const int code_syscall_aligned = round_up(sizeof(code_syscall), sizeof(long));
static inline void __always_unused __check_code_syscall(void)
{
BUILD_BUG_ON(code_syscall_aligned != BUILTIN_SYSCALL_SIZE);
BUILD_BUG_ON(!is_log2(sizeof(code_syscall)));
}
int sigreturn_prep_regs_plain(struct rt_sigframe *sigframe, user_regs_struct_t *regs, user_fpregs_struct_t *fpregs)
{
struct fpsimd_context *fpsimd = RT_SIGFRAME_FPU(sigframe);
memcpy(sigframe->uc.uc_mcontext.regs, regs->regs, sizeof(regs->regs));
sigframe->uc.uc_mcontext.sp = regs->sp;
sigframe->uc.uc_mcontext.pc = regs->pc;
sigframe->uc.uc_mcontext.pstate = regs->pstate;
memcpy(fpsimd->vregs, fpregs->vregs, 32 * sizeof(__uint128_t));
fpsimd->fpsr = fpregs->fpsr;
fpsimd->fpcr = fpregs->fpcr;
fpsimd->head.magic = FPSIMD_MAGIC;
fpsimd->head.size = sizeof(*fpsimd);
return 0;
}
int sigreturn_prep_fpu_frame_plain(struct rt_sigframe *sigframe, struct rt_sigframe *rsigframe)
{
return 0;
}
int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs, user_fpregs_struct_t *ext_regs, save_regs_t save,
void *arg, __maybe_unused unsigned long flags)
{
user_fpregs_struct_t tmp, *fpsimd = ext_regs ? ext_regs : &tmp;
struct iovec iov;
int ret;
pr_info("Dumping GP/FPU registers for %d\n", pid);
iov.iov_base = regs;
iov.iov_len = sizeof(user_regs_struct_t);
if ((ret = ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))) {
pr_perror("Failed to obtain CPU registers for %d", pid);
goto err;
}
iov.iov_base = fpsimd;
iov.iov_len = sizeof(*fpsimd);
if ((ret = ptrace(PTRACE_GETREGSET, pid, NT_PRFPREG, &iov))) {
pr_perror("Failed to obtain FPU registers for %d", pid);
goto err;
}
ret = save(arg, regs, fpsimd);
err:
return ret;
}
int compel_set_task_ext_regs(pid_t pid, user_fpregs_struct_t *ext_regs)
{
struct iovec iov;
pr_info("Restoring GP/FPU registers for %d\n", pid);
iov.iov_base = ext_regs;
iov.iov_len = sizeof(*ext_regs);
if (ptrace(PTRACE_SETREGSET, pid, NT_PRFPREG, &iov)) {
pr_perror("Failed to set FPU registers for %d", pid);
return -1;
}
return 0;
}
int compel_syscall(struct parasite_ctl *ctl, int nr, long *ret, unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4, unsigned long arg5, unsigned long arg6)
{
user_regs_struct_t regs = ctl->orig.regs;
int err;
regs.regs[8] = (unsigned long)nr;
regs.regs[0] = arg1;
regs.regs[1] = arg2;
regs.regs[2] = arg3;
regs.regs[3] = arg4;
regs.regs[4] = arg5;
regs.regs[5] = arg6;
regs.regs[6] = 0;
regs.regs[7] = 0;
err = compel_execute_syscall(ctl, ®s, code_syscall);
*ret = regs.regs[0];
return err;
}
void *remote_mmap(struct parasite_ctl *ctl, void *addr, size_t length, int prot, int flags, int fd, off_t offset)
{
long map;
int err;
err = compel_syscall(ctl, __NR_mmap, &map, (unsigned long)addr, length, prot, flags, fd, offset);
if (err < 0 || (long)map < 0)
map = 0;
return (void *)map;
}
void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs)
{
regs->pc = new_ip;
if (stack)
regs->sp = (unsigned long)stack;
}
bool arch_can_dump_task(struct parasite_ctl *ctl)
{
/*
* TODO: Add proper check here
*/
return true;
}
int arch_fetch_sas(struct parasite_ctl *ctl, struct rt_sigframe *s)
{
long ret;
int err;
err = compel_syscall(ctl, __NR_sigaltstack, &ret, 0, (unsigned long)&s->uc.uc_stack, 0, 0, 0, 0);
return err ? err : ret;
}
/*
* Range for task size calculated from the following Linux kernel files:
* arch/arm64/include/asm/memory.h
* arch/arm64/Kconfig
*
* TODO: handle 32 bit tasks
*/
#define TASK_SIZE_MIN (1UL << 39)
#define TASK_SIZE_MAX (1UL << 48)
unsigned long compel_task_size(void)
{
unsigned long task_size;
for (task_size = TASK_SIZE_MIN; task_size < TASK_SIZE_MAX; task_size <<= 1)
if (munmap((void *)task_size, page_size()))
break;
return task_size;
}
|
