diff options
author | Alex Shi <alex.shi@linaro.org> | 2015-06-25 16:17:21 +0800 |
---|---|---|
committer | Alex Shi <alex.shi@linaro.org> | 2015-06-25 16:19:06 +0800 |
commit | bd4e9a26373331ef6f185500c72a8836eb7c82d9 (patch) | |
tree | 13384e7649be7bb88ab9524efcbc602be85d5020 /arch/arc/kernel/signal.c | |
parent | 2528dbd348dd541e090594b7aac3f62351078388 (diff) | |
parent | 2cb9802eeb7f919f97df05b16ec128f4f5af366d (diff) |
Merge branch 'linux-linaro-lsk-v3.14' into linux-linaro-lsk-v3.14-androidlsk-v3.14-15.07-android
Conflicts:
fs/exec.c
Solutions:
follow commit d221244a7
sched: move no_new_privs into new atomic flags
to use task_no_new_privs(current).
Diffstat (limited to 'arch/arc/kernel/signal.c')
-rw-r--r-- | arch/arc/kernel/signal.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index d68b410595c8..a0c63fc48457 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -131,6 +131,15 @@ SYSCALL_DEFINE0(rt_sigreturn) /* Don't restart from sigreturn */ syscall_wont_restart(regs); + /* + * Ensure that sigreturn always returns to user mode (in case the + * regs saved on user stack got fudged between save and sigreturn) + * Otherwise it is easy to panic the kernel with a custom + * signal handler and/or restorer which clobberes the status32/ret + * to return to a bogus location in kernel mode. + */ + regs->status32 |= STATUS_U_MASK; + return regs->r0; badframe: @@ -234,8 +243,11 @@ setup_rt_frame(int signo, struct k_sigaction *ka, siginfo_t *info, /* * handler returns using sigreturn stub provided already by userpsace + * If not, nuke the process right away */ - BUG_ON(!(ka->sa.sa_flags & SA_RESTORER)); + if(!(ka->sa.sa_flags & SA_RESTORER)) + return 1; + regs->blink = (unsigned long)ka->sa.sa_restorer; /* User Stack for signal handler will be above the frame just carved */ @@ -302,12 +314,12 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, struct pt_regs *regs) { sigset_t *oldset = sigmask_to_save(); - int ret; + int failed; /* Set up the stack frame */ - ret = setup_rt_frame(sig, ka, info, oldset, regs); + failed = setup_rt_frame(sig, ka, info, oldset, regs); - if (ret) + if (failed) force_sigsegv(sig, current); else signal_delivered(sig, info, ka, regs, 0); |