#include <linux/user.h>
#include <linux/security.h>
#include <linux/audit.h>
+#include <linux/seccomp.h>
+#include <linux/signal.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
* in exit.c or in signal.c.
*/
-/* determines which flags the user has access to. */
-/* 1 = access 0 = no access */
-#define FLAG_MASK 0x44dd5UL
+/*
+ * Determines which flags the user has access to [1 = access, 0 = no access].
+ * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
+ * Also masks reserved bits (63-22, 15, 5, 3, 1).
+ */
+#define FLAG_MASK 0x54dd5UL
/* set's the trap flag. */
#define TRAP_FLAG 0x100UL
return 0;
}
+#define LDT_SEGMENT 4
+
+unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
+{
+ unsigned long addr, seg;
+
+ addr = regs->rip;
+ seg = regs->cs & 0xffff;
+
+ /*
+ * We'll assume that the code segments in the GDT
+ * are all zero-based. That is largely true: the
+ * TLS segments are used for data, and the PNPBIOS
+ * and APM bios ones we just ignore here.
+ */
+ if (seg & LDT_SEGMENT) {
+ u32 *desc;
+ unsigned long base;
+
+ down(&child->mm->context.sem);
+ desc = child->mm->context.ldt + (seg & ~7);
+ base = (desc[0] >> 16) | ((desc[1] & 0xff) << 16) | (desc[1] & 0xff000000);
+
+ /* 16-bit code segment? */
+ if (!((desc[1] >> 22) & 1))
+ addr &= 0xffff;
+ addr += base;
+ up(&child->mm->context.sem);
+ }
+ return addr;
+}
+
+static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
+{
+ int i, copied;
+ unsigned char opcode[16];
+ unsigned long addr = convert_rip_to_linear(child, regs);
+
+ copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
+ for (i = 0; i < copied; i++) {
+ switch (opcode[i]) {
+ /* popf */
+ case 0x9d:
+ return 1;
+
+ /* CHECKME: 64 65 */
+
+ /* opcode and address size prefixes */
+ case 0x66: case 0x67:
+ continue;
+ /* irrelevant prefixes (segment overrides and repeats) */
+ case 0x26: case 0x2e:
+ case 0x36: case 0x3e:
+ case 0x64: case 0x65:
+ case 0xf0: case 0xf2: case 0xf3:
+ continue;
+
+ /* REX prefixes */
+ case 0x40 ... 0x4f:
+ continue;
+
+ /* CHECKME: f0, f2, f3 */
+
+ /*
+ * pushf: NOTE! We should probably not let
+ * the user see the TF bit being set. But
+ * it's more pain than it's worth to avoid
+ * it, and a debugger could emulate this
+ * all in user space if it _really_ cares.
+ */
+ case 0x9c:
+ default:
+ return 0;
+ }
+ }
+ return 0;
+}
+
+static void set_singlestep(struct task_struct *child)
+{
+ struct pt_regs *regs = task_pt_regs(child);
+
+ /*
+ * Always set TIF_SINGLESTEP - this guarantees that
+ * we single-step system calls etc.. This will also
+ * cause us to set TF when returning to user mode.
+ */
+ set_tsk_thread_flag(child, TIF_SINGLESTEP);
+
+ /*
+ * If TF was already set, don't do anything else
+ */
+ if (regs->eflags & TRAP_FLAG)
+ return;
+
+ /* Set TF on the kernel stack.. */
+ regs->eflags |= TRAP_FLAG;
+
+ /*
+ * ..but if TF is changed by the instruction we will trace,
+ * don't mark it as being "us" that set it, so that we
+ * won't clear it by hand later.
+ *
+ * AK: this is not enough, LAHF and IRET can change TF in user space too.
+ */
+ if (is_at_popf(child, regs))
+ return;
+
+ child->ptrace |= PT_DTRACE;
+}
+
+static void clear_singlestep(struct task_struct *child)
+{
+ /* Always clear TIF_SINGLESTEP... */
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+
+ /* But touch TF only if it was set by us.. */
+ if (child->ptrace & PT_DTRACE) {
+ struct pt_regs *regs = task_pt_regs(child);
+ regs->eflags &= ~TRAP_FLAG;
+ child->ptrace &= ~PT_DTRACE;
+ }
+}
+
/*
* Called by kernel/ptrace.c when detaching..
*
*/
void ptrace_disable(struct task_struct *child)
{
- long tmp;
-
- tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
- put_stack_long(child, EFL_OFFSET, tmp);
+ clear_singlestep(child);
}
static int putreg(struct task_struct *child,
value &= 0xffff;
return 0;
case offsetof(struct user_regs_struct,fs_base):
- if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
- return -EIO;
+ if (value >= TASK_SIZE_OF(child))
+ return -EIO;
child->thread.fs = value;
return 0;
case offsetof(struct user_regs_struct,gs_base):
- if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
- return -EIO;
+ if (value >= TASK_SIZE_OF(child))
+ return -EIO;
child->thread.gs = value;
return 0;
case offsetof(struct user_regs_struct, eflags):
}
-asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data)
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
- struct task_struct *child;
long i, ret;
unsigned ui;
- /* This lock_kernel fixes a subtle race with suid exec */
- lock_kernel();
- ret = -EPERM;
- if (request == PTRACE_TRACEME) {
- /* are we already being traced? */
- if (current->ptrace & PT_PTRACED)
- goto out;
- ret = security_ptrace(current->parent, current);
- if (ret)
- goto out;
- /* set the ptrace bit in the process flags. */
- current->ptrace |= PT_PTRACED;
- ret = 0;
- goto out;
- }
- ret = -ESRCH;
- read_lock(&tasklist_lock);
- child = find_task_by_pid(pid);
- if (child)
- get_task_struct(child);
- read_unlock(&tasklist_lock);
- if (!child)
- goto out;
- if (!vx_check(vx_task_xid(child), VX_WATCH|VX_IDENT))
- goto out_tsk;
-
- ret = -EPERM;
- if (pid == 1) /* you may not mess with init */
- goto out_tsk;
-
- if (request == PTRACE_ATTACH) {
- ret = ptrace_attach(child);
- goto out_tsk;
- }
- ret = ptrace_check_attach(child, request == PTRACE_KILL);
- if (ret < 0)
- goto out_tsk;
-
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKTEXT: /* read word at location addr. */
ret = -EIO;
if (copied != sizeof(tmp))
break;
- ret = put_user(tmp,(unsigned long *) data);
+ ret = put_user(tmp,(unsigned long __user *) data);
break;
}
break;
switch (addr) {
- case 0 ... sizeof(struct user_regs_struct):
+ case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
tmp = getreg(child, addr);
break;
case offsetof(struct user, u_debugreg[0]):
tmp = 0;
break;
}
- ret = put_user(tmp,(unsigned long *) data);
+ ret = put_user(tmp,(unsigned long __user *) data);
break;
}
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
+ {
+ int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;
ret = -EIO;
if ((addr & 7) ||
addr > sizeof(struct user) - 7)
break;
switch (addr) {
- case 0 ... sizeof(struct user_regs_struct):
+ case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
ret = putreg(child, addr, data);
break;
/* Disallows to set a breakpoint into the vsyscall */
case offsetof(struct user, u_debugreg[0]):
- if (data >= TASK_SIZE-7) break;
+ if (data >= TASK_SIZE_OF(child) - dsize) break;
child->thread.debugreg0 = data;
ret = 0;
break;
case offsetof(struct user, u_debugreg[1]):
- if (data >= TASK_SIZE-7) break;
+ if (data >= TASK_SIZE_OF(child) - dsize) break;
child->thread.debugreg1 = data;
ret = 0;
break;
case offsetof(struct user, u_debugreg[2]):
- if (data >= TASK_SIZE-7) break;
+ if (data >= TASK_SIZE_OF(child) - dsize) break;
child->thread.debugreg2 = data;
ret = 0;
break;
case offsetof(struct user, u_debugreg[3]):
- if (data >= TASK_SIZE-7) break;
+ if (data >= TASK_SIZE_OF(child) - dsize) break;
child->thread.debugreg3 = data;
ret = 0;
break;
ret = 0;
break;
case offsetof(struct user, u_debugreg[7]):
- data &= ~DR_CONTROL_RESERVED;
- for(i=0; i<4; i++)
- if ((0x5454 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
+ /* See arch/i386/kernel/ptrace.c for an explanation of
+ * this awkward check.*/
+ data &= ~DR_CONTROL_RESERVED;
+ for(i=0; i<4; i++)
+ if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
break;
if (i == 4) {
child->thread.debugreg7 = data;
break;
}
break;
+ }
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
- case PTRACE_CONT: { /* restart after signal. */
- long tmp;
+ case PTRACE_CONT: /* restart after signal. */
ret = -EIO;
- if ((unsigned long) data > _NSIG)
+ if (!valid_signal(data))
break;
if (request == PTRACE_SYSCALL)
set_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
else
clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
child->exit_code = data;
- /* make sure the single step bit is not set. */
- tmp = get_stack_long(child, EFL_OFFSET);
- tmp &= ~TRAP_FLAG;
- put_stack_long(child, EFL_OFFSET,tmp);
+ /* make sure the single step bit is not set. */
+ clear_singlestep(child);
wake_up_process(child);
ret = 0;
break;
- }
#ifdef CONFIG_IA32_EMULATION
/* This makes only sense with 32bit programs. Allow a
don't use it against 64bit processes, use
PTRACE_ARCH_PRCTL instead. */
case PTRACE_SET_THREAD_AREA: {
+ struct user_desc __user *p;
int old;
- get_user(old, &((struct user_desc *)data)->entry_number);
- put_user(addr, &((struct user_desc *)data)->entry_number);
- ret = do_set_thread_area(&child->thread,
- (struct user_desc *)data);
- put_user(old, &((struct user_desc *)data)->entry_number);
+ p = (struct user_desc __user *)data;
+ get_user(old, &p->entry_number);
+ put_user(addr, &p->entry_number);
+ ret = do_set_thread_area(&child->thread, p);
+ put_user(old, &p->entry_number);
break;
case PTRACE_GET_THREAD_AREA:
- get_user(old, &((struct user_desc *)data)->entry_number);
- put_user(addr, &((struct user_desc *)data)->entry_number);
- ret = do_get_thread_area(&child->thread,
- (struct user_desc *)data);
- put_user(old, &((struct user_desc *)data)->entry_number);
+ p = (struct user_desc __user *)data;
+ get_user(old, &p->entry_number);
+ put_user(addr, &p->entry_number);
+ ret = do_get_thread_area(&child->thread, p);
+ put_user(old, &p->entry_number);
break;
}
#endif
* perhaps it should be put in the status that it wants to
* exit.
*/
- case PTRACE_KILL: {
- long tmp;
-
+ case PTRACE_KILL:
ret = 0;
- if (child->state == TASK_ZOMBIE) /* already dead */
+ if (child->exit_state == EXIT_ZOMBIE) /* already dead */
break;
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
child->exit_code = SIGKILL;
/* make sure the single step bit is not set. */
- tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
- put_stack_long(child, EFL_OFFSET, tmp);
+ clear_singlestep(child);
wake_up_process(child);
break;
- }
-
- case PTRACE_SINGLESTEP: { /* set the trap flag. */
- long tmp;
+ case PTRACE_SINGLESTEP: /* set the trap flag. */
ret = -EIO;
- if ((unsigned long) data > _NSIG)
+ if (!valid_signal(data))
break;
clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
- if ((child->ptrace & PT_DTRACE) == 0) {
- /* Spurious delayed TF traps may occur */
- child->ptrace |= PT_DTRACE;
- }
- tmp = get_stack_long(child, EFL_OFFSET) | TRAP_FLAG;
- put_stack_long(child, EFL_OFFSET, tmp);
+ set_singlestep(child);
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
break;
- }
case PTRACE_DETACH:
/* detach a process that was attached. */
break;
case PTRACE_GETREGS: { /* Get all gp regs from the child. */
- if (!access_ok(VERIFY_WRITE, (unsigned *)data, FRAME_SIZE)) {
+ if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
+ sizeof(struct user_regs_struct))) {
ret = -EIO;
break;
}
+ ret = 0;
for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
- __put_user(getreg(child, ui),(unsigned long *) data);
+ ret |= __put_user(getreg(child, ui),(unsigned long __user *) data);
data += sizeof(long);
}
- ret = 0;
break;
}
case PTRACE_SETREGS: { /* Set all gp regs in the child. */
unsigned long tmp;
- if (!access_ok(VERIFY_READ, (unsigned *)data, FRAME_SIZE)) {
+ if (!access_ok(VERIFY_READ, (unsigned __user *)data,
+ sizeof(struct user_regs_struct))) {
ret = -EIO;
break;
}
+ ret = 0;
for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
- __get_user(tmp, (unsigned long *) data);
+ ret |= __get_user(tmp, (unsigned long __user *) data);
putreg(child, ui, tmp);
data += sizeof(long);
}
- ret = 0;
break;
}
case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
- if (!access_ok(VERIFY_WRITE, (unsigned *)data,
+ if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
sizeof(struct user_i387_struct))) {
ret = -EIO;
break;
}
- ret = get_fpregs((struct user_i387_struct *)data, child);
+ ret = get_fpregs((struct user_i387_struct __user *)data, child);
break;
}
case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
- if (!access_ok(VERIFY_READ, (unsigned *)data,
+ if (!access_ok(VERIFY_READ, (unsigned __user *)data,
sizeof(struct user_i387_struct))) {
ret = -EIO;
break;
}
- child->used_math = 1;
- ret = set_fpregs(child, (struct user_i387_struct *)data);
+ set_stopped_child_used_math(child);
+ ret = set_fpregs(child, (struct user_i387_struct __user *)data);
break;
}
ret = ptrace_request(child, request, addr, data);
break;
}
-out_tsk:
- put_task_struct(child);
-out:
- unlock_kernel();
return ret;
}
asmlinkage void syscall_trace_enter(struct pt_regs *regs)
{
- if (unlikely(current->audit_context))
- audit_syscall_entry(current, regs->orig_rax,
- regs->rdi, regs->rsi,
- regs->rdx, regs->r10);
+ /* do the secure computing check first */
+ secure_computing(regs->orig_rax);
if (test_thread_flag(TIF_SYSCALL_TRACE)
&& (current->ptrace & PT_PTRACED))
syscall_trace(regs);
+
+ if (unlikely(current->audit_context)) {
+ if (test_thread_flag(TIF_IA32)) {
+ audit_syscall_entry(AUDIT_ARCH_I386,
+ regs->orig_rax,
+ regs->rbx, regs->rcx,
+ regs->rdx, regs->rsi);
+ } else {
+ audit_syscall_entry(AUDIT_ARCH_X86_64,
+ regs->orig_rax,
+ regs->rdi, regs->rsi,
+ regs->rdx, regs->r10);
+ }
+ }
}
asmlinkage void syscall_trace_leave(struct pt_regs *regs)
{
if (unlikely(current->audit_context))
- audit_syscall_exit(current, regs->rax);
+ audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax);
- if (test_thread_flag(TIF_SYSCALL_TRACE)
+ if ((test_thread_flag(TIF_SYSCALL_TRACE)
+ || test_thread_flag(TIF_SINGLESTEP))
&& (current->ptrace & PT_PTRACED))
syscall_trace(regs);
}
git://git.onelab.eu / linux-2.6.git / blobdiff