diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index a29028d3d46e..6aa053462400 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -339,7 +339,6 @@ void flush_thread(void) tls_thread_flush(); flush_ptrace_hw_breakpoint(current); flush_tagged_addr_state(); - flush_mte_state(); } void release_thread(struct task_struct *dead_task) @@ -529,6 +528,31 @@ static void erratum_1418040_thread_switch(struct task_struct *prev, write_sysreg(val, cntkctl_el1); } +static void update_sctlr_el1(u64 sctlr) +{ + /* + * EnIA must not be cleared while in the kernel as this is necessary for + * in-kernel PAC. It will be cleared on kernel exit if needed. + */ + sysreg_clear_set(sctlr_el1, SCTLR_USER_MASK & ~SCTLR_ELx_ENIA, sctlr); + + /* ISB required for the kernel uaccess routines when setting TCF0. */ + isb(); +} + +void set_task_sctlr_el1(u64 sctlr) +{ + /* + * __switch_to() checks current->thread.sctlr as an + * optimisation. Disable preemption so that it does not see + * the variable update before the SCTLR_EL1 one. + */ + preempt_disable(); + current->thread.sctlr_user = sctlr; + update_sctlr_el1(sctlr); + preempt_enable(); +} + /* * Thread switching. */ @@ -544,6 +568,7 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, entry_task_switch(next); ssbs_thread_switch(next); erratum_1418040_thread_switch(prev, next); + ptrauth_thread_switch_user(next); /* * Complete any pending TLB or cache maintenance on this CPU in case @@ -559,6 +584,9 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, * registers. */ mte_thread_switch(next); + /* avoid expensive SCTLR_EL1 accesses if no change */ + if (prev->thread.sctlr_user != next->thread.sctlr_user) + update_sctlr_el1(next->thread.sctlr_user); /* the actual thread switch */ last = cpu_switch_to(prev, next); @@ -608,7 +636,8 @@ void arch_setup_new_exec(void) { current->mm->context.flags = is_compat_task() ? MMCF_AARCH32 : 0; - ptrauth_thread_init_user(current); + ptrauth_thread_init_user(); + mte_thread_init_user(); if (task_spec_ssb_noexec(current)) { arch_prctl_spec_ctrl_set(current, PR_SPEC_STORE_BYPASS, |