From f8380f976804533df4c6c3d3a0b2cd03c2d262bc Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 15 Dec 2025 17:52:06 +0100 Subject: rseq: Provide static branch for time slice extensions Guard the time slice extension functionality with a static key, which can be disabled on the kernel command line. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251215155708.733429292@linutronix.de --- kernel/rseq.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'kernel') diff --git a/kernel/rseq.c b/kernel/rseq.c index 07c324d5a201..bf75268580ef 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -483,3 +483,20 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len, int, flags, u32 efault: return -EFAULT; } + +#ifdef CONFIG_RSEQ_SLICE_EXTENSION +DEFINE_STATIC_KEY_TRUE(rseq_slice_extension_key); + +static int __init rseq_slice_cmdline(char *str) +{ + bool on; + + if (kstrtobool(str, &on)) + return 0; + + if (!on) + static_branch_disable(&rseq_slice_extension_key); + return 1; +} +__setup("rseq_slice_ext=", rseq_slice_cmdline); +#endif /* CONFIG_RSEQ_SLICE_EXTENSION */ -- cgit v1.2.3