diff options
| -rw-r--r-- | include/uapi/linux/rseq.h | 3 | ||||
| -rw-r--r-- | kernel/rseq.c | 12 |
2 files changed, 12 insertions, 3 deletions
diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h index 6afc219d1545..863c4a00a66b 100644 --- a/include/uapi/linux/rseq.h +++ b/include/uapi/linux/rseq.h @@ -19,7 +19,8 @@ enum rseq_cpu_id_state { }; enum rseq_flags { - RSEQ_FLAG_UNREGISTER = (1 << 0), + RSEQ_FLAG_UNREGISTER = (1 << 0), + RSEQ_FLAG_SLICE_EXT_DEFAULT_ON = (1 << 1), }; enum rseq_cs_flags_bit { diff --git a/kernel/rseq.c b/kernel/rseq.c index 275d70114107..1c5490a172a8 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -424,7 +424,7 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len, int, flags, u32 return 0; } - if (unlikely(flags)) + if (unlikely(flags & ~(RSEQ_FLAG_SLICE_EXT_DEFAULT_ON))) return -EINVAL; if (current->rseq.usrptr) { @@ -459,8 +459,12 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len, int, flags, u32 if (!access_ok(rseq, rseq_len)) return -EFAULT; - if (IS_ENABLED(CONFIG_RSEQ_SLICE_EXTENSION)) + if (IS_ENABLED(CONFIG_RSEQ_SLICE_EXTENSION)) { rseqfl |= RSEQ_CS_FLAG_SLICE_EXT_AVAILABLE; + if (rseq_slice_extension_enabled() && + (flags & RSEQ_FLAG_SLICE_EXT_DEFAULT_ON)) + rseqfl |= RSEQ_CS_FLAG_SLICE_EXT_ENABLED; + } scoped_user_write_access(rseq, efault) { /* @@ -488,6 +492,10 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len, int, flags, u32 current->rseq.len = rseq_len; current->rseq.sig = sig; +#ifdef CONFIG_RSEQ_SLICE_EXTENSION + current->rseq.slice.state.enabled = !!(rseqfl & RSEQ_CS_FLAG_SLICE_EXT_ENABLED); +#endif + /* * If rseq was previously inactive, and has just been * registered, ensure the cpu_id_start and cpu_id fields |