Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (ba0f4722) · Commits · 戴 / test

Pull rseq fixes from Ingo Molnar: "Two rseq bugfixes: - CLONE_VM !CLONE_THREAD didn't work properly, the kernel would end up corrupting the TLS of the parent. Technically a change in the ABI but the previous behavior couldn't resonably have been relied on by applications so this looks like a valid exception to the ABI rule. - Make the RSEQ_FLAG_UNREGISTER ABI behavior consistent with the handling of other flags. This is not thought to impact any applications either" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rseq: Unregister rseq for clone CLONE_VM rseq: Reject unknown flags on rseq unregister

include/linux/sched.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -1929,11 +1929,11 @@ static inline void rseq_migrate(struct task_struct *t)

		/*
		* If parent process has a registered restartable sequences area, the
		* child inherits. Only applies when forking a process, not a thread.
		* child inherits. Unregister rseq for a clone with CLONE_VM set.
		*/
		static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
		{
		if (clone_flags & CLONE_THREAD) {
		if (clone_flags & CLONE_VM) {
		t->rseq = NULL;
		t->rseq_sig = 0;
		t->rseq_event_mask = 0;

kernel/rseq.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -310,6 +310,8 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len,
		int ret;

		if (flags & RSEQ_FLAG_UNREGISTER) {
		if (flags & ~RSEQ_FLAG_UNREGISTER)
		return -EINVAL;
		/* Unregister rseq for current thread. */
		if (current->rseq != rseq \|\| !current->rseq)
		return -EINVAL;

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