* in exit.c or in signal.c.
*/
-/* determines which flags the user has access to. */
-/* 1 = access 0 = no access */
-#define FLAG_MASK 0x00044dd5
+/*
+ * Determines which flags the user has access to [1 = access, 0 = no access].
+ * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9).
+ * Also masks reserved bits (31-22, 15, 5, 3, 1).
+ */
+#define FLAG_MASK 0x00050dd5
/* set's the trap flag. */
#define TRAP_FLAG 0x100
void ptrace_disable(struct task_struct *child)
{
clear_singlestep(child);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
}
/*
return 0;
}
-asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
- struct task_struct *child;
struct user * dummy = NULL;
int i, ret;
unsigned long __user *datap = (unsigned long __user *)data;
- 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. */
}
break;
+ case PTRACE_SYSEMU: /* continue and stop at next syscall, which will not be executed */
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: /* restart after signal. */
ret = -EIO;
if (!valid_signal(data))
break;
- if (request == PTRACE_SYSCALL) {
+ if (request == PTRACE_SYSEMU) {
+ set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ } else if (request == PTRACE_SYSCALL) {
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- }
- else {
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+ } else {
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}
child->exit_code = data;
wake_up_process(child);
break;
+ case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */
case PTRACE_SINGLESTEP: /* set the trap flag. */
ret = -EIO;
if (!valid_signal(data))
break;
+
+ if (request == PTRACE_SYSEMU_SINGLESTEP)
+ set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+ else
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
set_singlestep(child);
child->exit_code = data;
ret = ptrace_request(child, request, addr, data);
break;
}
-out_tsk:
- put_task_struct(child);
-out:
- unlock_kernel();
+ out_tsk:
return ret;
}
info.si_code = TRAP_BRKPT;
/* User-mode eip? */
- info.si_addr = user_mode(regs) ? (void __user *) regs->eip : NULL;
+ info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;
/* Send us the fakey SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
* - triggered by current->work.syscall_trace
*/
__attribute__((regparm(3)))
-void do_syscall_trace(struct pt_regs *regs, int entryexit)
+int do_syscall_trace(struct pt_regs *regs, int entryexit)
{
- /* do the secure computing check first */
- secure_computing(regs->orig_eax);
+ int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
+ /*
+ * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
+ * interception
+ */
+ int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
+ int ret = 0;
- if (unlikely(current->audit_context) && entryexit)
- audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax);
+ /* do the secure computing check first */
+ if (!entryexit)
+ secure_computing(regs->orig_eax);
+
+ if (unlikely(current->audit_context)) {
+ if (entryexit)
+ audit_syscall_exit(AUDITSC_RESULT(regs->eax),
+ regs->eax);
+ /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
+ * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
+ * not used, entry.S will call us only on syscall exit, not
+ * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
+ * calling send_sigtrap() on syscall entry.
+ *
+ * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
+ * is_singlestep is false, despite his name, so we will still do
+ * the correct thing.
+ */
+ else if (is_singlestep)
+ goto out;
+ }
if (!(current->ptrace & PT_PTRACED))
goto out;
+ /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
+ * and then is resumed with SYSEMU_SINGLESTEP, it will come in
+ * here. We have to check this and return */
+ if (is_sysemu && entryexit)
+ return 0;
+
/* Fake a debug trap */
- if (test_thread_flag(TIF_SINGLESTEP))
+ if (is_singlestep)
send_sigtrap(current, regs, 0);
- if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
goto out;
/* the 0x80 provides a way for the tracing parent to distinguish
between a syscall stop and SIGTRAP delivery */
- ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
+ /* Note that the debugger could change the result of test_thread_flag!*/
+ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0));
/*
* this isn't the same as continuing with a signal, but it will do
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
- out:
+ ret = is_sysemu;
+out:
if (unlikely(current->audit_context) && !entryexit)
- audit_syscall_entry(current, AUDIT_ARCH_I386, regs->orig_eax,
+ audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax,
regs->ebx, regs->ecx, regs->edx, regs->esi);
+ if (ret == 0)
+ return 0;
+ regs->orig_eax = -1; /* force skip of syscall restarting */
+ if (unlikely(current->audit_context))
+ audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax);
+ return 1;
}
git://git.onelab.eu / linux-2.6.git / blobdiff