mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-05-24 10:39:52 +00:00
0dafcbe128
UML enables TRACE_IRQFLAGS_SUPPORT but doesn't actually implement
it. It seems to have been added for lockdep support, but that can't
actually really work well without IRQ flags tracing, as is also
very noisily reported when enabling CONFIG_DEBUG_LOCKDEP.
Implement it now.
Fixes: 711553efa5 ("[PATCH] uml: declare in Kconfig our partial LOCKDEP support")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
141 lines
3.3 KiB
C
141 lines
3.3 KiB
C
/*
|
|
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/ftrace.h>
|
|
#include <asm/siginfo.h>
|
|
#include <asm/signal.h>
|
|
#include <asm/unistd.h>
|
|
#include <frame_kern.h>
|
|
#include <kern_util.h>
|
|
#include <os.h>
|
|
|
|
EXPORT_SYMBOL(block_signals);
|
|
EXPORT_SYMBOL(unblock_signals);
|
|
|
|
void block_signals_trace(void)
|
|
{
|
|
block_signals();
|
|
if (current_thread_info())
|
|
trace_hardirqs_off();
|
|
}
|
|
|
|
void unblock_signals_trace(void)
|
|
{
|
|
if (current_thread_info())
|
|
trace_hardirqs_on();
|
|
unblock_signals();
|
|
}
|
|
|
|
void um_trace_signals_on(void)
|
|
{
|
|
if (current_thread_info())
|
|
trace_hardirqs_on();
|
|
}
|
|
|
|
void um_trace_signals_off(void)
|
|
{
|
|
if (current_thread_info())
|
|
trace_hardirqs_off();
|
|
}
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
sigset_t *oldset = sigmask_to_save();
|
|
int singlestep = 0;
|
|
unsigned long sp;
|
|
int err;
|
|
|
|
if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
|
|
singlestep = 1;
|
|
|
|
/* Did we come from a system call? */
|
|
if (PT_REGS_SYSCALL_NR(regs) >= 0) {
|
|
/* If so, check system call restarting.. */
|
|
switch (PT_REGS_SYSCALL_RET(regs)) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
PT_REGS_SYSCALL_RET(regs) = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
|
|
PT_REGS_SYSCALL_RET(regs) = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
|
|
break;
|
|
}
|
|
}
|
|
|
|
sp = PT_REGS_SP(regs);
|
|
if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
|
|
sp = current->sas_ss_sp + current->sas_ss_size;
|
|
|
|
#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
|
|
if (!(ksig->ka.sa.sa_flags & SA_SIGINFO))
|
|
err = setup_signal_stack_sc(sp, ksig, regs, oldset);
|
|
else
|
|
#endif
|
|
err = setup_signal_stack_si(sp, ksig, regs, oldset);
|
|
|
|
signal_setup_done(err, ksig, singlestep);
|
|
}
|
|
|
|
void do_signal(struct pt_regs *regs)
|
|
{
|
|
struct ksignal ksig;
|
|
int handled_sig = 0;
|
|
|
|
while (get_signal(&ksig)) {
|
|
handled_sig = 1;
|
|
/* Whee! Actually deliver the signal. */
|
|
handle_signal(&ksig, regs);
|
|
}
|
|
|
|
/* Did we come from a system call? */
|
|
if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
|
|
/* Restart the system call - no handlers present */
|
|
switch (PT_REGS_SYSCALL_RET(regs)) {
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
break;
|
|
case -ERESTART_RESTARTBLOCK:
|
|
PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This closes a way to execute a system call on the host. If
|
|
* you set a breakpoint on a system call instruction and singlestep
|
|
* from it, the tracing thread used to PTRACE_SINGLESTEP the process
|
|
* rather than PTRACE_SYSCALL it, allowing the system call to execute
|
|
* on the host. The tracing thread will check this flag and
|
|
* PTRACE_SYSCALL if necessary.
|
|
*/
|
|
if (current->ptrace & PT_DTRACE)
|
|
current->thread.singlestep_syscall =
|
|
is_syscall(PT_REGS_IP(¤t->thread.regs));
|
|
|
|
/*
|
|
* if there's no signal to deliver, we just put the saved sigmask
|
|
* back
|
|
*/
|
|
if (!handled_sig)
|
|
restore_saved_sigmask();
|
|
}
|