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#include <stdlib.h>
#include <sys/ptrace.h>
#include <sys/types.h>
#include <string.h>
#include <compel/plugins/std/syscall-codes.h>
#include <compel/asm/processor-flags.h>
#include <errno.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"
/*
* Injected syscall instruction
*/
const char code_syscall[] = {
0x00, 0x00, 0x00, 0xef, /* SVC #0 */
0xf0, 0x01, 0xf0, 0xe7 /* UDF #32 */
};
static const int
code_syscall_aligned = round_up(sizeof(code_syscall), sizeof(long));
static inline __always_unused void __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 aux_sigframe *aux = (struct aux_sigframe *)(void *)&sigframe->sig.uc.uc_regspace;
sigframe->sig.uc.uc_mcontext.arm_r0 = regs->ARM_r0;
sigframe->sig.uc.uc_mcontext.arm_r1 = regs->ARM_r1;
sigframe->sig.uc.uc_mcontext.arm_r2 = regs->ARM_r2;
sigframe->sig.uc.uc_mcontext.arm_r3 = regs->ARM_r3;
sigframe->sig.uc.uc_mcontext.arm_r4 = regs->ARM_r4;
sigframe->sig.uc.uc_mcontext.arm_r5 = regs->ARM_r5;
sigframe->sig.uc.uc_mcontext.arm_r6 = regs->ARM_r6;
sigframe->sig.uc.uc_mcontext.arm_r7 = regs->ARM_r7;
sigframe->sig.uc.uc_mcontext.arm_r8 = regs->ARM_r8;
sigframe->sig.uc.uc_mcontext.arm_r9 = regs->ARM_r9;
sigframe->sig.uc.uc_mcontext.arm_r10 = regs->ARM_r10;
sigframe->sig.uc.uc_mcontext.arm_fp = regs->ARM_fp;
sigframe->sig.uc.uc_mcontext.arm_ip = regs->ARM_ip;
sigframe->sig.uc.uc_mcontext.arm_sp = regs->ARM_sp;
sigframe->sig.uc.uc_mcontext.arm_lr = regs->ARM_lr;
sigframe->sig.uc.uc_mcontext.arm_pc = regs->ARM_pc;
sigframe->sig.uc.uc_mcontext.arm_cpsr = regs->ARM_cpsr;
memcpy(&aux->vfp.ufp.fpregs, &fpregs->fpregs, sizeof(aux->vfp.ufp.fpregs));
aux->vfp.ufp.fpscr = fpregs->fpscr;
aux->vfp.magic = VFP_MAGIC;
aux->vfp.size = VFP_STORAGE_SIZE;
return 0;
}
int sigreturn_prep_fpu_frame_plain(struct rt_sigframe *sigframe,
struct rt_sigframe *rsigframe)
{
return 0;
}
#define PTRACE_GETVFPREGS 27
int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
void *arg, __maybe_unused unsigned long flags)
{
user_fpregs_struct_t vfp;
int ret = -1;
pr_info("Dumping GP/FPU registers for %d\n", pid);
if (ptrace(PTRACE_GETVFPREGS, pid, NULL, &vfp)) {
pr_perror("Can't obtain FPU registers for %d", pid);
goto err;
}
/* Did we come from a system call? */
if ((int)regs->ARM_ORIG_r0 >= 0) {
/* Restart the system call */
switch ((long)(int)regs->ARM_r0) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->ARM_r0 = regs->ARM_ORIG_r0;
regs->ARM_pc -= 4;
break;
case -ERESTART_RESTARTBLOCK:
pr_warn("Will restore %d with interrupted system call\n", pid);
regs->ARM_r0 = -EINTR;
break;
}
}
ret = save(arg, regs, &vfp);
err:
return ret;
}
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.ARM_r7 = (unsigned long)nr;
regs.ARM_r0 = arg1;
regs.ARM_r1 = arg2;
regs.ARM_r2 = arg3;
regs.ARM_r3 = arg4;
regs.ARM_r4 = arg5;
regs.ARM_r5 = arg6;
err = compel_execute_syscall(ctl, ®s, code_syscall);
*ret = regs.ARM_r0;
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;
if (offset & ~PAGE_MASK)
return 0;
err = compel_syscall(ctl, __NR_mmap2, &map,
(unsigned long)addr, length, prot, flags, fd, offset >> 12);
if (err < 0 || map > ctl->ictx.task_size)
map = 0;
return (void *)map;
}
void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs)
{
regs->ARM_pc = new_ip;
if (stack)
regs->ARM_sp = (unsigned long)stack;
/* Make sure flags are in known state */
regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | MODE32_BIT;
}
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->sig.uc.uc_stack,
0, 0, 0, 0);
return err ? err : ret;
}
/*
* Range for task size calculated from the following Linux kernel files:
* arch/arm/include/asm/memory.h
* arch/arm/Kconfig (PAGE_OFFSET values in Memory split section)
*/
#define TASK_SIZE_MIN 0x3f000000
#define TASK_SIZE_MAX 0xbf000000
#define SZ_1G 0x40000000
unsigned long compel_task_size(void)
{
unsigned long task_size;
for (task_size = TASK_SIZE_MIN; task_size < TASK_SIZE_MAX; task_size += SZ_1G)
if (munmap((void *)task_size, page_size()))
break;
return task_size;
}
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