android_kernel_xiaomi_sm8350/arch/um/kernel/skas/mem_user.c
Bodo Stroesser 07bf731e4b [PATCH] uml: skas0 stubs now check system call return values
Change syscall-stub's data to include a "expected retval".

Stub now checks syscalls retval and aborts execution of syscall list, if
retval != expected retval.

run_syscall_stub prints the data of the failed syscall, using the data pointer
and retval written by the stub to the beginning of the stack.

one_syscall_stub is removed, to simplify code, because only some instructions
are saved by one_syscall_stub, no host-syscall.

Using the stub with additional data (modify_ldt via stub)
is prepared also.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00

282 lines
8.0 KiB
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <asm/page.h>
#include <asm/unistd.h>
#include "mem_user.h"
#include "mem.h"
#include "skas.h"
#include "user.h"
#include "os.h"
#include "proc_mm.h"
#include "ptrace_user.h"
#include "user_util.h"
#include "kern_util.h"
#include "task.h"
#include "registers.h"
#include "uml-config.h"
#include "sysdep/ptrace.h"
#include "sysdep/stub.h"
extern unsigned long batch_syscall_stub, __syscall_stub_start;
extern void wait_stub_done(int pid, int sig, char * fname);
static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
unsigned long *stack)
{
if(stack == NULL){
stack = (unsigned long *) mm_idp->stack + 2;
*stack = 0;
}
return stack;
}
extern int proc_mm;
int single_count = 0;
int multi_count = 0;
int multi_op_count = 0;
static long do_syscall_stub(struct mm_id *mm_idp, void **addr)
{
unsigned long regs[MAX_REG_NR];
unsigned long *data;
unsigned long *syscall;
long ret, offset;
int n, pid = mm_idp->u.pid;
if(proc_mm)
#warning Need to look up userspace_pid by cpu
pid = userspace_pid[0];
multi_count++;
get_safe_registers(regs);
regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
((unsigned long) &batch_syscall_stub -
(unsigned long) &__syscall_stub_start);
n = ptrace_setregs(pid, regs);
if(n < 0)
panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
n);
wait_stub_done(pid, 0, "do_syscall_stub");
/* When the stub stops, we find the following values on the
* beginning of the stack:
* (long )return_value
* (long )offset to failed sycall-data (0, if no error)
*/
ret = *((unsigned long *) mm_idp->stack);
offset = *((unsigned long *) mm_idp->stack + 1);
if (offset) {
data = (unsigned long *)(mm_idp->stack +
offset - UML_CONFIG_STUB_DATA);
syscall = (unsigned long *)((unsigned long)data + data[0]);
printk("do_syscall_stub: syscall %ld failed, return value = "
"0x%lx, expected return value = 0x%lx\n",
syscall[0], ret, syscall[7]);
printk(" syscall parameters: "
"0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
syscall[1], syscall[2], syscall[3],
syscall[4], syscall[5], syscall[6]);
for(n = 1; n < data[0]/sizeof(long); n++) {
if(n == 1)
printk(" additional syscall data:");
if(n % 4 == 1)
printk("\n ");
printk(" 0x%lx", data[n]);
}
if(n > 1)
printk("\n");
}
else ret = 0;
*addr = check_init_stack(mm_idp, NULL);
return ret;
}
long run_syscall_stub(struct mm_id * mm_idp, int syscall,
unsigned long *args, long expected, void **addr,
int done)
{
unsigned long *stack = check_init_stack(mm_idp, *addr);
if(done && *addr == NULL)
single_count++;
*stack += sizeof(long);
stack += *stack / sizeof(long);
*stack++ = syscall;
*stack++ = args[0];
*stack++ = args[1];
*stack++ = args[2];
*stack++ = args[3];
*stack++ = args[4];
*stack++ = args[5];
*stack++ = expected;
*stack = 0;
multi_op_count++;
if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
PAGE_SIZE - 10 * sizeof(long))){
*addr = stack;
return 0;
}
return do_syscall_stub(mm_idp, addr);
}
long syscall_stub_data(struct mm_id * mm_idp,
unsigned long *data, int data_count,
void **addr, void **stub_addr)
{
unsigned long *stack;
int ret = 0;
/* If *addr still is uninitialized, it *must* contain NULL.
* Thus in this case do_syscall_stub correctly won't be called.
*/
if((((unsigned long) *addr) & ~PAGE_MASK) >=
PAGE_SIZE - (10 + data_count) * sizeof(long)) {
ret = do_syscall_stub(mm_idp, addr);
/* in case of error, don't overwrite data on stack */
if(ret)
return ret;
}
stack = check_init_stack(mm_idp, *addr);
*addr = stack;
*stack = data_count * sizeof(long);
memcpy(stack + 1, data, data_count * sizeof(long));
*stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
UML_CONFIG_STUB_DATA);
return 0;
}
int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
int r, int w, int x, int phys_fd, unsigned long long offset,
int done, void **data)
{
int prot, ret;
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
if(proc_mm){
struct proc_mm_op map;
int fd = mm_idp->u.mm_fd;
map = ((struct proc_mm_op) { .op = MM_MMAP,
.u =
{ .mmap =
{ .addr = virt,
.len = len,
.prot = prot,
.flags = MAP_SHARED |
MAP_FIXED,
.fd = phys_fd,
.offset= offset
} } } );
ret = os_write_file(fd, &map, sizeof(map));
if(ret != sizeof(map))
printk("map : /proc/mm map failed, err = %d\n", -ret);
else ret = 0;
}
else {
unsigned long args[] = { virt, len, prot,
MAP_SHARED | MAP_FIXED, phys_fd,
MMAP_OFFSET(offset) };
ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
data, done);
}
return ret;
}
int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
void **data)
{
int ret;
if(proc_mm){
struct proc_mm_op unmap;
int fd = mm_idp->u.mm_fd;
unmap = ((struct proc_mm_op) { .op = MM_MUNMAP,
.u =
{ .munmap =
{ .addr =
(unsigned long) addr,
.len = len } } } );
ret = os_write_file(fd, &unmap, sizeof(unmap));
if(ret != sizeof(unmap))
printk("unmap - proc_mm write returned %d\n", ret);
else ret = 0;
}
else {
unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
0 };
ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
data, done);
if(ret < 0)
printk("munmap stub failed, errno = %d\n", ret);
}
return ret;
}
int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
int r, int w, int x, int done, void **data)
{
struct proc_mm_op protect;
int prot, ret;
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
if(proc_mm){
int fd = mm_idp->u.mm_fd;
protect = ((struct proc_mm_op) { .op = MM_MPROTECT,
.u =
{ .mprotect =
{ .addr =
(unsigned long) addr,
.len = len,
.prot = prot } } } );
ret = os_write_file(fd, &protect, sizeof(protect));
if(ret != sizeof(protect))
printk("protect failed, err = %d", -ret);
else ret = 0;
}
else {
unsigned long args[] = { addr, len, prot, 0, 0, 0 };
ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
data, done);
}
return ret;
}
void before_mem_skas(unsigned long unused)
{
}