[PATCH 2/3] MIPS: signal: Return immediately if call fails

From: Tiezhu Yang
Date: Fri Dec 17 2021 - 22:23:50 EST


When debug sigaltstack(), copy_siginfo_to_user() fails first in
setup_rt_frame() if the alternate signal stack is too small, so
it should return immediately if call fails, no need to call the
following functions.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
arch/mips/kernel/signal.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index c1632e8..4cd3969 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -761,15 +761,28 @@ static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
return -EFAULT;

/* Create siginfo. */
- err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
+ err = copy_siginfo_to_user(&frame->rs_info, &ksig->info);
+ if (err)
+ return -EFAULT;

/* Create the ucontext. */
- err |= __put_user(0, &frame->rs_uc.uc_flags);
- err |= __put_user(NULL, &frame->rs_uc.uc_link);
- err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
- err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
- err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
+ err = __put_user(0, &frame->rs_uc.uc_flags);
+ if (err)
+ return -EFAULT;
+
+ err = __put_user(NULL, &frame->rs_uc.uc_link);
+ if (err)
+ return -EFAULT;
+
+ err = __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
+ if (err)
+ return -EFAULT;
+
+ err = setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+ if (err)
+ return -EFAULT;

+ err = __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;

--
2.1.0