diff options
| author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2018-06-02 08:43:58 -0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-06-06 11:58:32 +0200 |
| commit | d6761b8fd96967f7ff4b16c6875e94929a897916 (patch) | |
| tree | 7ddebb20825b5e855623a652acb7d2873169efcd /arch | |
| parent | 338035edc9b96cd63f4bc823db5f36c617c560bf (diff) | |
x86: Add support for restartable sequences
Call the rseq_handle_notify_resume() function on return to userspace if
TIF_NOTIFY_RESUME thread flag is set.
Perform fixup on the pre-signal frame when a signal is delivered on top
of a restartable sequence critical section.
Check that system calls are not invoked from within rseq critical
sections by invoking rseq_signal() from syscall_return_slowpath().
With CONFIG_DEBUG_RSEQ, such behavior results in termination of the
process with SIGSEGV.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Hunter <ahh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20180602124408.8430-7-mathieu.desnoyers@efficios.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/entry/common.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/signal.c | 6 |
3 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1fe24b624d44..c320ce005b02 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -182,6 +182,7 @@ config X86 select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION select HAVE_STACK_VALIDATION if X86_64 + select HAVE_RSEQ select HAVE_SYSCALL_TRACEPOINTS select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index fbf6a6c3fd2d..92190879b228 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -164,6 +164,7 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags) if (cached_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + rseq_handle_notify_resume(regs); } if (cached_flags & _TIF_USER_RETURN_NOTIFY) @@ -254,6 +255,8 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs) WARN(irqs_disabled(), "syscall %ld left IRQs disabled", regs->orig_ax)) local_irq_enable(); + rseq_syscall(regs); + /* * First do one-time work. If these work items are enabled, we * want to run them exactly once per syscall exit with IRQs on. diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index da270b95fe4d..445ca11ff863 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -688,6 +688,12 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) sigset_t *set = sigmask_to_save(); compat_sigset_t *cset = (compat_sigset_t *) set; + /* + * Increment event counter and perform fixup for the pre-signal + * frame. + */ + rseq_signal_deliver(regs); + /* Set up the stack frame */ if (is_ia32_frame(ksig)) { if (ksig->ka.sa.sa_flags & SA_SIGINFO) |