Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'arc-4.0-fixes-part-2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC fixes from Vineet Gupta:
"We found some issues with signal handling taking down the system. I
know its late, but these are important and all marked for stable.
ARC signal handling related fixes uncovered during recent testing of
NPTL tools"
* tag 'arc-4.0-fixes-part-2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: signal handling robustify
ARC: SA_SIGINFO ucontext regs off-by-one
+18
-6
+18
-6
arch/arc/kernel/signal.c
+18
-6
arch/arc/kernel/signal.c
···
67
67
sigset_t *set)
68
68
{
69
69
int err;
70
-
err = __copy_to_user(&(sf->uc.uc_mcontext.regs), regs,
70
+
err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), regs,
71
71
sizeof(sf->uc.uc_mcontext.regs.scratch));
72
72
err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
73
73
···
83
83
if (!err)
84
84
set_current_blocked(&set);
85
85
86
-
err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs),
86
+
err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs.scratch),
87
87
sizeof(sf->uc.uc_mcontext.regs.scratch));
88
88
89
89
return err;
···
130
130
131
131
/* Don't restart from sigreturn */
132
132
syscall_wont_restart(regs);
133
+
134
+
/*
135
+
* Ensure that sigreturn always returns to user mode (in case the
136
+
* regs saved on user stack got fudged between save and sigreturn)
137
+
* Otherwise it is easy to panic the kernel with a custom
138
+
* signal handler and/or restorer which clobberes the status32/ret
139
+
* to return to a bogus location in kernel mode.
140
+
*/
141
+
regs->status32 |= STATUS_U_MASK;
133
142
134
143
return regs->r0;
135
144
···
238
229
239
230
/*
240
231
* handler returns using sigreturn stub provided already by userpsace
232
+
* If not, nuke the process right away
241
233
*/
242
-
BUG_ON(!(ksig->ka.sa.sa_flags & SA_RESTORER));
234
+
if(!(ksig->ka.sa.sa_flags & SA_RESTORER))
235
+
return 1;
236
+
243
237
regs->blink = (unsigned long)ksig->ka.sa.sa_restorer;
244
238
245
239
/* User Stack for signal handler will be above the frame just carved */
···
308
296
handle_signal(struct ksignal *ksig, struct pt_regs *regs)
309
297
{
310
298
sigset_t *oldset = sigmask_to_save();
311
-
int ret;
299
+
int failed;
312
300
313
301
/* Set up the stack frame */
314
-
ret = setup_rt_frame(ksig, oldset, regs);
302
+
failed = setup_rt_frame(ksig, oldset, regs);
315
303
316
-
signal_setup_done(ret, ksig, 0);
304
+
signal_setup_done(failed, ksig, 0);
317
305
}
318
306
319
307
void do_signal(struct pt_regs *regs)