* 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 (*((unsigned long *)stack));
}
-static inline struct pt_regs *get_child_regs(struct task_struct *task)
-{
- struct pt_regs *regs = (void *)task->thread.rsp0;
- return regs - 1;
-}
-
/*
* this routine will put a word on the processes privileged stack.
* the offset is how far from the base addr as stored in the TSS.
return addr;
}
-static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
+static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
{
int i, copied;
- unsigned char opcode[16];
+ unsigned char opcode[15];
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:
+ /* popf and iret */
+ case 0x9d: case 0xcf:
return 1;
/* CHECKME: 64 65 */
case 0x26: case 0x2e:
case 0x36: case 0x3e:
case 0x64: case 0x65:
- case 0xf0: case 0xf2: case 0xf3:
+ case 0xf2: case 0xf3:
continue;
- /* REX prefixes */
case 0x40 ... 0x4f:
+ if (regs->cs != __USER_CS)
+ /* 32-bit mode: register increment */
+ return 0;
+ /* 64-bit mode: REX prefix */
continue;
- /* CHECKME: f0, f2, f3 */
+ /* CHECKME: f2, f3 */
/*
* pushf: NOTE! We should probably not let
static void set_singlestep(struct task_struct *child)
{
- struct pt_regs *regs = get_child_regs(child);
+ struct pt_regs *regs = task_pt_regs(child);
/*
* Always set TIF_SINGLESTEP - this guarantees that
* ..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))
+ if (is_setting_trap_flag(child, regs))
return;
child->ptrace |= PT_DTRACE;
/* But touch TF only if it was set by us.. */
if (child->ptrace & PT_DTRACE) {
- struct pt_regs *regs = get_child_regs(child);
+ struct pt_regs *regs = task_pt_regs(child);
regs->eflags &= ~TRAP_FLAG;
child->ptrace &= ~PT_DTRACE;
}
return -EIO;
value &= 0xffff;
break;
- case offsetof(struct user_regs_struct, rip):
- /* Check if the new RIP address is canonical */
- if (value >= TASK_SIZE_OF(child))
- return -EIO;
- break;
}
put_stack_long(child, regno - sizeof(struct pt_regs), value);
return 0;
case offsetof(struct user, u_debugreg[7]):
/* See arch/i386/kernel/ptrace.c for an explanation of
* this awkward check.*/
- data &= ~DR_CONTROL_RESERVED;
- for(i=0; i<4; i++)
- if ((0x5454 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
+ 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;
+ child->thread.debugreg7 = data;
+ if (data)
+ set_tsk_thread_flag(child, TIF_DEBUG);
+ else
+ clear_tsk_thread_flag(child, TIF_DEBUG);
ret = 0;
- }
+ }
break;
}
break;
if (unlikely(current->audit_context)) {
if (test_thread_flag(TIF_IA32)) {
- audit_syscall_entry(current, AUDIT_ARCH_I386,
+ audit_syscall_entry(AUDIT_ARCH_I386,
regs->orig_rax,
regs->rbx, regs->rcx,
regs->rdx, regs->rsi);
} else {
- audit_syscall_entry(current, AUDIT_ARCH_X86_64,
+ 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, AUDITSC_RESULT(regs->rax), regs->rax);
+ audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax);
if ((test_thread_flag(TIF_SYSCALL_TRACE)
|| test_thread_flag(TIF_SINGLESTEP))