Commit 07bf731e authored by Bodo Stroesser's avatar Bodo Stroesser Committed by Linus Torvalds

[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: default avatarBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 8b51304e
......@@ -38,9 +38,9 @@ extern void mprotect_kernel_vm(int w);
extern void force_flush_all(void);
extern void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force,
void *(*do_ops)(union mm_context *,
struct host_vm_op *, int, int,
void *));
int (*do_ops)(union mm_context *,
struct host_vm_op *, int, int,
void **));
extern int flush_tlb_kernel_range_common(unsigned long start,
unsigned long end);
......
......@@ -24,14 +24,14 @@ extern void new_thread_proc(void *stack, void (*handler)(int sig));
extern void remove_sigstack(void);
extern void new_thread_handler(int sig);
extern void handle_syscall(union uml_pt_regs *regs);
extern void *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);
extern void *unmap(struct mm_id * mm_idp, void *addr,
unsigned long len, int done, void *data);
extern void *protect(struct mm_id * mm_idp, unsigned long addr,
unsigned long len, int r, int w, int x, int done,
void *data);
extern 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);
extern int unmap(struct mm_id * mm_idp, void *addr, unsigned long len,
int done, void **data);
extern int protect(struct mm_id * mm_idp, unsigned long addr,
unsigned long len, int r, int w, int x, int done,
void **data);
extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
extern int new_mm(int from, unsigned long stack);
extern int start_userspace(unsigned long stub_stack);
......@@ -39,16 +39,11 @@ extern int copy_context_skas0(unsigned long stack, int pid);
extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
extern long execute_syscall_skas(void *r);
extern unsigned long current_stub_stack(void);
extern long run_syscall_stub(struct mm_id * mm_idp,
int syscall, unsigned long *args, long expected,
void **addr, int done);
extern long syscall_stub_data(struct mm_id * mm_idp,
unsigned long *data, int data_count,
void **addr, void **stub_addr);
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
......@@ -5,13 +5,14 @@
#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 "mm_id.h"
#include "skas.h"
#include "user.h"
#include "os.h"
#include "proc_mm.h"
......@@ -23,56 +24,99 @@
#include "uml-config.h"
#include "sysdep/ptrace.h"
#include "sysdep/stub.h"
#include "skas.h"
extern unsigned long syscall_stub, batch_syscall_stub, __syscall_stub_start;
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 one_syscall_stub(struct mm_id * mm_idp, int syscall,
unsigned long *args)
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;
unsigned long regs[MAX_REG_NR];
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) &syscall_stub -
((unsigned long) &batch_syscall_stub -
(unsigned long) &__syscall_stub_start);
/* XXX Don't have a define for starting a syscall */
regs[REGS_SYSCALL_NR] = syscall;
regs[REGS_SYSCALL_ARG1] = args[0];
regs[REGS_SYSCALL_ARG2] = args[1];
regs[REGS_SYSCALL_ARG3] = args[2];
regs[REGS_SYSCALL_ARG4] = args[3];
regs[REGS_SYSCALL_ARG5] = args[4];
regs[REGS_SYSCALL_ARG6] = args[5];
n = ptrace_setregs(pid, regs);
if(n < 0){
printk("one_syscall_stub : PTRACE_SETREGS failed, "
"errno = %d\n", n);
return(n);
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;
wait_stub_done(pid, 0, "one_syscall_stub");
*addr = check_init_stack(mm_idp, NULL);
return(*((unsigned long *) mm_idp->stack));
return ret;
}
int multi_count = 0;
int multi_op_count = 0;
static long many_syscall_stub(struct mm_id * mm_idp, int syscall,
unsigned long *args, int done, void **addr_out)
long run_syscall_stub(struct mm_id * mm_idp, int syscall,
unsigned long *args, long expected, void **addr,
int done)
{
unsigned long regs[MAX_REG_NR], *stack;
int n, pid = mm_idp->u.pid;
unsigned long *stack = check_init_stack(mm_idp, *addr);
if(done && *addr == NULL)
single_count++;
*stack += sizeof(long);
stack += *stack / sizeof(long);
stack = *addr_out;
if(stack == NULL)
stack = (unsigned long *) current_stub_stack();
*stack++ = syscall;
*stack++ = args[0];
*stack++ = args[1];
......@@ -80,53 +124,55 @@ static long many_syscall_stub(struct mm_id * mm_idp, int syscall,
*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 - 8 * sizeof(long))){
*addr_out = stack;
PAGE_SIZE - 10 * sizeof(long))){
*addr = stack;
return 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);
regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA;
return do_syscall_stub(mm_idp, addr);
}
n = ptrace_setregs(pid, regs);
if(n < 0){
printk("many_syscall_stub : PTRACE_SETREGS failed, "
"errno = %d\n", n);
return(n);
}
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;
}
wait_stub_done(pid, 0, "many_syscall_stub");
stack = (unsigned long *) mm_idp->stack;
stack = check_init_stack(mm_idp, *addr);
*addr = stack;
*addr_out = stack;
return(*stack);
}
*stack = data_count * sizeof(long);
static long run_syscall_stub(struct mm_id * mm_idp, int syscall,
unsigned long *args, void **addr, int done)
{
long res;
memcpy(stack + 1, data, data_count * sizeof(long));
if((*addr == NULL) && done)
res = one_syscall_stub(mm_idp, syscall, args);
else res = many_syscall_stub(mm_idp, syscall, args, done, addr);
*stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
UML_CONFIG_STUB_DATA);
return res;
return 0;
}
void *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 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, n;
int prot, ret;
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
......@@ -146,29 +192,27 @@ void *map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
.fd = phys_fd,
.offset= offset
} } } );
n = os_write_file(fd, &map, sizeof(map));
if(n != sizeof(map))
printk("map : /proc/mm map failed, err = %d\n", -n);
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 {
long res;
unsigned long args[] = { virt, len, prot,
MAP_SHARED | MAP_FIXED, phys_fd,
MMAP_OFFSET(offset) };
res = run_syscall_stub(mm_idp, STUB_MMAP_NR, args,
&data, done);
if((void *) res == MAP_FAILED)
printk("mmap stub failed, errno = %d\n", res);
ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
data, done);
}
return data;
return ret;
}
void *unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
void *data)
int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
void **data)
{
int n;
int ret;
if(proc_mm){
struct proc_mm_op unmap;
......@@ -180,29 +224,29 @@ void *unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
{ .addr =
(unsigned long) addr,
.len = len } } } );
n = os_write_file(fd, &unmap, sizeof(unmap));
if(n != sizeof(unmap))
printk("unmap - proc_mm write returned %d\n", n);
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 {
int res;
unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
0 };
res = run_syscall_stub(mm_idp, __NR_munmap, args,
&data, done);
if(res < 0)
printk("munmap stub failed, errno = %d\n", res);
ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
data, done);
if(ret < 0)
printk("munmap stub failed, errno = %d\n", ret);
}
return data;
return ret;
}
void *protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
int r, int w, int x, int done, void *data)
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, n;
int prot, ret;
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
......@@ -217,21 +261,19 @@ void *protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
.len = len,
.prot = prot } } } );
n = os_write_file(fd, &protect, sizeof(protect));
if(n != sizeof(protect))
panic("protect failed, err = %d", -n);
ret = os_write_file(fd, &protect, sizeof(protect));
if(ret != sizeof(protect))
printk("protect failed, err = %d", -ret);
else ret = 0;
}
else {
int res;
unsigned long args[] = { addr, len, prot, 0, 0, 0 };
res = run_syscall_stub(mm_idp, __NR_mprotect, args,
&data, done);
if(res < 0)
panic("mprotect stub failed, errno = %d\n", res);
ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
data, done);
}
return data;
return ret;
}
void before_mem_skas(unsigned long unused)
......
......@@ -18,30 +18,31 @@
#include "os.h"
#include "tlb.h"
static void *do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
int finished, void *flush)
static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
int finished, void **flush)
{
struct host_vm_op *op;
int i;
int i, ret = 0;
for(i = 0; i <= last; i++){
for(i = 0; i <= last && !ret; i++){
op = &ops[i];
switch(op->type){
case MMAP:
flush = map(&mmu->skas.id, op->u.mmap.addr,
op->u.mmap.len, op->u.mmap.r, op->u.mmap.w,
op->u.mmap.x, op->u.mmap.fd,
op->u.mmap.offset, finished, flush);
ret = map(&mmu->skas.id, op->u.mmap.addr,
op->u.mmap.len, op->u.mmap.r, op->u.mmap.w,
op->u.mmap.x, op->u.mmap.fd,
op->u.mmap.offset, finished, flush);
break;
case MUNMAP:
flush = unmap(&mmu->skas.id, (void *) op->u.munmap.addr,
op->u.munmap.len, finished, flush);
ret = unmap(&mmu->skas.id,
(void *) op->u.munmap.addr,
op->u.munmap.len, finished, flush);
break;
case MPROTECT:
flush = protect(&mmu->skas.id, op->u.mprotect.addr,
op->u.mprotect.len, op->u.mprotect.r,
op->u.mprotect.w, op->u.mprotect.x,
finished, flush);
ret = protect(&mmu->skas.id, op->u.mprotect.addr,
op->u.mprotect.len, op->u.mprotect.r,
op->u.mprotect.w, op->u.mprotect.x,
finished, flush);
break;
default:
printk("Unknown op type %d in do_ops\n", op->type);
......@@ -49,7 +50,7 @@ static void *do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
}
}
return flush;
return ret;
}
extern int proc_mm;
......
......@@ -16,115 +16,117 @@
#include "os.h"
static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
int r, int w, int x, struct host_vm_op *ops, int index,
int r, int w, int x, struct host_vm_op *ops, int *index,
int last_filled, union mm_context *mmu, void **flush,
void *(*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void *))
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
__u64 offset;
struct host_vm_op *last;
int fd;
int fd, ret = 0;
fd = phys_mapping(phys, &offset);
if(index != -1){
last = &ops[index];
if(*index != -1){
last = &ops[*index];
if((last->type == MMAP) &&
(last->u.mmap.addr + last->u.mmap.len == virt) &&
(last->u.mmap.r == r) && (last->u.mmap.w == w) &&
(last->u.mmap.x == x) && (last->u.mmap.fd == fd) &&
(last->u.mmap.offset + last->u.mmap.len == offset)){
last->u.mmap.len += len;
return index;
return 0;
}
}
if(index == last_filled){
*flush = (*do_ops)(mmu, ops, last_filled, 0, *flush);
index = -1;
if(*index == last_filled){
ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
*index = -1;
}
ops[++index] = ((struct host_vm_op) { .type = MMAP,
.u = { .mmap = {
.addr = virt,
.len = len,
.r = r,
.w = w,
.x = x,
.fd = fd,
.offset = offset }
} });
return index;
ops[++*index] = ((struct host_vm_op) { .type = MMAP,
.u = { .mmap = {
.addr = virt,
.len = len,
.r = r,
.w = w,
.x = x,
.fd = fd,
.offset = offset }
} });
return ret;
}
static int add_munmap(unsigned long addr, unsigned long len,
struct host_vm_op *ops, int index, int last_filled,
struct host_vm_op *ops, int *index, int last_filled,
union mm_context *mmu, void **flush,
void *(*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void *))
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
struct host_vm_op *last;
int ret = 0;
if(index != -1){
last = &ops[index];
if(*index != -1){
last = &ops[*index];
if((last->type == MUNMAP) &&
(last->u.munmap.addr + last->u.mmap.len == addr)){
last->u.munmap.len += len;
return index;
return 0;
}
}
if(index == last_filled){
*flush = (*do_ops)(mmu, ops, last_filled, 0, *flush);
index = -1;
if(*index == last_filled){
ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
*index = -1;
}
ops[++index] = ((struct host_vm_op) { .type = MUNMAP,
.u = { .munmap = {
.addr = addr,
.len = len } } });
return index;
ops[++*index] = ((struct host_vm_op) { .type = MUNMAP,
.u = { .munmap = {
.addr = addr,
.len = len } } });
return ret;
}
static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
int x, struct host_vm_op *ops, int index,
int x, struct host_vm_op *ops, int *index,
int last_filled, union mm_context *mmu, void **flush,
void *(*do_ops)(union mm_context *,
struct host_vm_op *, int, int, void *))
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
struct host_vm_op *last;
int ret = 0;
if(index != -1){
last = &ops[index];
if(*index != -1){
last = &ops[*index];
if((last->type == MPROTECT) &&
(last->u.mprotect.addr + last->u.mprotect.len == addr) &&
(last->u.mprotect.r == r) && (last->u.mprotect.w == w) &&
(last->u.mprotect.x == x)){
last->u.mprotect.len += len;
return index;
return 0;
}
}