diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rseq_entry.h | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/include/linux/rseq_entry.h b/include/linux/rseq_entry.h index 8d04611056aa..fc77b9dd0932 100644 --- a/include/linux/rseq_entry.h +++ b/include/linux/rseq_entry.h @@ -102,9 +102,17 @@ static __always_inline bool rseq_arm_slice_extension_timer(void) return __rseq_arm_slice_extension_timer(); } +static __always_inline void rseq_slice_clear_grant(struct task_struct *t) +{ + if (IS_ENABLED(CONFIG_RSEQ_STATS) && t->rseq.slice.state.granted) + rseq_stat_inc(rseq_stats.s_revoked); + t->rseq.slice.state.granted = false; +} + #else /* CONFIG_RSEQ_SLICE_EXTENSION */ static inline bool rseq_slice_extension_enabled(void) { return false; } static inline bool rseq_arm_slice_extension_timer(void) { return false; } +static inline void rseq_slice_clear_grant(struct task_struct *t) { } #endif /* !CONFIG_RSEQ_SLICE_EXTENSION */ bool rseq_debug_update_user_cs(struct task_struct *t, struct pt_regs *regs, unsigned long csaddr); @@ -391,8 +399,15 @@ bool rseq_set_ids_get_csaddr(struct task_struct *t, struct rseq_ids *ids, unsafe_put_user(ids->mm_cid, &rseq->mm_cid, efault); if (csaddr) unsafe_get_user(*csaddr, &rseq->rseq_cs, efault); + + /* Open coded, so it's in the same user access region */ + if (rseq_slice_extension_enabled()) { + /* Unconditionally clear it, no point in conditionals */ + unsafe_put_user(0U, &rseq->slice_ctrl.all, efault); + } } + rseq_slice_clear_grant(t); /* Cache the new values */ t->rseq.ids.cpu_cid = ids->cpu_cid; rseq_stat_inc(rseq_stats.ids); @@ -488,8 +503,17 @@ static __always_inline bool rseq_exit_user_update(struct pt_regs *regs, struct t */ u64 csaddr; - if (unlikely(get_user_inline(csaddr, &rseq->rseq_cs))) - return false; + scoped_user_rw_access(rseq, efault) { + unsafe_get_user(csaddr, &rseq->rseq_cs, efault); + + /* Open coded, so it's in the same user access region */ + if (rseq_slice_extension_enabled()) { + /* Unconditionally clear it, no point in conditionals */ + unsafe_put_user(0U, &rseq->slice_ctrl.all, efault); + } + } + + rseq_slice_clear_grant(t); if (static_branch_unlikely(&rseq_debug_enabled) || unlikely(csaddr)) { if (unlikely(!rseq_update_user_cs(t, regs, csaddr))) @@ -505,6 +529,8 @@ static __always_inline bool rseq_exit_user_update(struct pt_regs *regs, struct t u32 node_id = cpu_to_node(ids.cpu_id); return rseq_update_usr(t, regs, &ids, node_id); +efault: + return false; } static __always_inline bool __rseq_exit_to_user_mode_restart(struct pt_regs *regs) |