diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 29 |
1 files changed, 8 insertions, 21 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index a47a40ec6ad9..71005cb0f4e0 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -422,16 +422,15 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, if (clone_flags & CLONE_SETTLS) p->thread.uw.tp_value = tls; } else { + /* + * A kthread has no context to ERET to, so ensure any buggy + * ERET is treated as an illegal exception return. + * + * When a user task is created from a kthread, childregs will + * be initialized by start_thread() or start_compat_thread(). + */ memset(childregs, 0, sizeof(struct pt_regs)); - childregs->pstate = PSR_MODE_EL1h; - if (IS_ENABLED(CONFIG_ARM64_UAO) && - cpus_have_const_cap(ARM64_HAS_UAO)) - childregs->pstate |= PSR_UAO_BIT; - - spectre_v4_enable_task_mitigation(p); - - if (system_uses_irq_prio_masking()) - childregs->pmr_save = GIC_PRIO_IRQON; + childregs->pstate = PSR_MODE_EL1h | PSR_IL_BIT; p->thread.cpu_context.x19 = stack_start; p->thread.cpu_context.x20 = stk_sz; @@ -461,17 +460,6 @@ static void tls_thread_switch(struct task_struct *next) write_sysreg(*task_user_tls(next), tpidr_el0); } -/* Restore the UAO state depending on next's addr_limit */ -void uao_thread_switch(struct task_struct *next) -{ - if (IS_ENABLED(CONFIG_ARM64_UAO)) { - if (task_thread_info(next)->addr_limit == KERNEL_DS) - asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO)); - else - asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO)); - } -} - /* * Force SSBS state on context-switch, since it may be lost after migrating * from a CPU which treats the bit as RES0 in a heterogeneous system. @@ -554,7 +542,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, hw_breakpoint_thread_switch(next); contextidr_thread_switch(next); entry_task_switch(next); - uao_thread_switch(next); ssbs_thread_switch(next); erratum_1418040_thread_switch(prev, next); |