diff options
| -rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/Kbuild | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/current.h | 22 | ||||
| -rw-r--r-- | arch/arm64/include/asm/smp.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/thread_info.h | 24 | ||||
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 8 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 41 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 11 | ||||
| -rw-r--r-- | arch/arm64/kernel/process.c | 16 | ||||
| -rw-r--r-- | arch/arm64/kernel/smp.c | 2 |
10 files changed, 73 insertions, 54 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 77a807a844ac..0b8227f23eed 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -109,6 +109,7 @@ config ARM64 select POWER_SUPPLY select SPARSE_IRQ select SYSCTL_EXCEPTION_TRACE + select THREAD_INFO_IN_TASK help ARM 64-bit (AArch64) Linux support. diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 44e1d7f10add..28196b18e394 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -1,7 +1,6 @@ generic-y += bugs.h generic-y += clkdev.h generic-y += cputime.h -generic-y += current.h generic-y += delay.h generic-y += div64.h generic-y += dma.h diff --git a/arch/arm64/include/asm/current.h b/arch/arm64/include/asm/current.h new file mode 100644 index 000000000000..f2bcbe2d9889 --- /dev/null +++ b/arch/arm64/include/asm/current.h @@ -0,0 +1,22 @@ +#ifndef __ASM_CURRENT_H +#define __ASM_CURRENT_H + +#include <linux/compiler.h> + +#include <asm/sysreg.h> + +#ifndef __ASSEMBLY__ + +struct task_struct; + +static __always_inline struct task_struct *get_current(void) +{ + return (struct task_struct *)read_sysreg(sp_el0); +} + +#define current get_current() + +#endif /* __ASSEMBLY__ */ + +#endif /* __ASM_CURRENT_H */ + diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h index 968b08de820d..a62db952ffcb 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -82,6 +82,7 @@ asmlinkage void secondary_start_kernel(void); */ struct secondary_data { void *stack; + struct task_struct *task; long status; }; diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index bce0f07483c1..c17ad4d213d0 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -47,41 +47,17 @@ typedef unsigned long mm_segment_t; struct thread_info { unsigned long flags; /* low level flags */ mm_segment_t addr_limit; /* address limit */ - struct task_struct *task; /* main task structure */ int preempt_count; /* 0 => preemptable, <0 => bug */ - int cpu; /* cpu */ }; #define INIT_THREAD_INFO(tsk) \ { \ - .task = &tsk, \ - .flags = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ } #define init_stack (init_thread_union.stack) -/* - * how to get the thread information struct from C - */ -static inline struct thread_info *current_thread_info(void) __attribute_const__; - -/* - * struct thread_info can be accessed directly via sp_el0. - * - * We don't use read_sysreg() as we want the compiler to cache the value where - * possible. - */ -static inline struct thread_info *current_thread_info(void) -{ - unsigned long sp_el0; - - asm ("mrs %0, sp_el0" : "=r" (sp_el0)); - - return (struct thread_info *)sp_el0; -} - #define thread_saved_pc(tsk) \ ((unsigned long)(tsk->thread.cpu_context.pc)) #define thread_saved_sp(tsk) \ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index d30b2321c0ee..c2dc9fa4f09b 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -36,9 +36,10 @@ int main(void) { DEFINE(TSK_ACTIVE_MM, offsetof(struct task_struct, active_mm)); BLANK(); - DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); - DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count)); - DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit)); + DEFINE(TSK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags)); + DEFINE(TSK_TI_PREEMPT, offsetof(struct task_struct, thread_info.preempt_count)); + DEFINE(TSK_TI_ADDR_LIMIT, offsetof(struct task_struct, thread_info.addr_limit)); + DEFINE(TSK_STACK, offsetof(struct task_struct, stack)); BLANK(); DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); BLANK(); @@ -121,6 +122,7 @@ int main(void) DEFINE(TZ_DSTTIME, offsetof(struct timezone, tz_dsttime)); BLANK(); DEFINE(CPU_BOOT_STACK, offsetof(struct secondary_data, stack)); + DEFINE(CPU_BOOT_TASK, offsetof(struct secondary_data, task)); BLANK(); #ifdef CONFIG_KVM_ARM_HOST DEFINE(VCPU_CONTEXT, offsetof(struct kvm_vcpu, arch.ctxt)); diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 2d4c83bc1f81..6349a8324b4f 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -90,9 +90,8 @@ .if \el == 0 mrs x21, sp_el0 - mov tsk, sp - and tsk, tsk, #~(THREAD_SIZE - 1) // Ensure MDSCR_EL1.SS is clear, - ldr x19, [tsk, #TI_FLAGS] // since we can unmask debug + ldr_this_cpu tsk, __entry_task, x20 // Ensure MDSCR_EL1.SS is clear, + ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug disable_step_tsk x19, x20 // exceptions when scheduling. mov x29, xzr // fp pointed to user-space @@ -100,10 +99,10 @@ add x21, sp, #S_FRAME_SIZE get_thread_info tsk /* Save the task's original addr_limit and set USER_DS (TASK_SIZE_64) */ - ldr x20, [tsk, #TI_ADDR_LIMIT] + ldr x20, [tsk, #TSK_TI_ADDR_LIMIT] str x20, [sp, #S_ORIG_ADDR_LIMIT] mov x20, #TASK_SIZE_64 - str x20, [tsk, #TI_ADDR_LIMIT] + str x20, [tsk, #TSK_TI_ADDR_LIMIT] /* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */ .endif /* \el == 0 */ mrs x22, elr_el1 @@ -139,7 +138,7 @@ .if \el != 0 /* Restore the task's original addr_limit. */ ldr x20, [sp, #S_ORIG_ADDR_LIMIT] - str x20, [tsk, #TI_ADDR_LIMIT] + str x20, [tsk, #TSK_TI_ADDR_LIMIT] /* No need to restore UAO, it will be restored from SPSR_EL1 */ .endif @@ -192,13 +191,14 @@ alternative_else_nop_endif mov x19, sp // preserve the original sp /* - * Compare sp with the current thread_info, if the top - * ~(THREAD_SIZE - 1) bits match, we are on a task stack, and - * should switch to the irq stack. + * Compare sp with the base of the task stack. + * If the top ~(THREAD_SIZE - 1) bits match, we are on a task stack, + * and should switch to the irq stack. */ - and x25, x19, #~(THREAD_SIZE - 1) - cmp x25, tsk - b.ne 9998f + ldr x25, [tsk, TSK_STACK] + eor x25, x25, x19 + and x25, x25, #~(THREAD_SIZE - 1) + cbnz x25, 9998f adr_this_cpu x25, irq_stack, x26 mov x26, #IRQ_STACK_START_SP @@ -427,9 +427,9 @@ el1_irq: irq_handler #ifdef CONFIG_PREEMPT - ldr w24, [tsk, #TI_PREEMPT] // get preempt count + ldr w24, [tsk, #TSK_TI_PREEMPT] // get preempt count cbnz w24, 1f // preempt count != 0 - ldr x0, [tsk, #TI_FLAGS] // get flags + ldr x0, [tsk, #TSK_TI_FLAGS] // get flags tbz x0, #TIF_NEED_RESCHED, 1f // needs rescheduling? bl el1_preempt 1: @@ -444,7 +444,7 @@ ENDPROC(el1_irq) el1_preempt: mov x24, lr 1: bl preempt_schedule_irq // irq en/disable is done inside - ldr x0, [tsk, #TI_FLAGS] // get new tasks TI_FLAGS + ldr x0, [tsk, #TSK_TI_FLAGS] // get new tasks TI_FLAGS tbnz x0, #TIF_NEED_RESCHED, 1b // needs rescheduling? ret x24 #endif @@ -674,8 +674,7 @@ ENTRY(cpu_switch_to) ldp x29, x9, [x8], #16 ldr lr, [x8] mov sp, x9 - and x9, x9, #~(THREAD_SIZE - 1) - msr sp_el0, x9 + msr sp_el0, x1 ret ENDPROC(cpu_switch_to) @@ -686,7 +685,7 @@ ENDPROC(cpu_switch_to) ret_fast_syscall: disable_irq // disable interrupts str x0, [sp, #S_X0] // returned x0 - ldr x1, [tsk, #TI_FLAGS] // re-check for syscall tracing + ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK cbnz x2, ret_fast_syscall_trace and x2, x1, #_TIF_WORK_MASK @@ -706,14 +705,14 @@ work_pending: #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_on // enabled while in userspace #endif - ldr x1, [tsk, #TI_FLAGS] // re-check for single-step + ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for single-step b finish_ret_to_user /* * "slow" syscall return path. */ ret_to_user: disable_irq // disable interrupts - ldr x1, [tsk, #TI_FLAGS] + ldr x1, [tsk, #TSK_TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending finish_ret_to_user: @@ -746,7 +745,7 @@ el0_svc_naked: // compat entry point enable_dbg_and_irq ct_user_exit 1 - ldr x16, [tsk, #TI_FLAGS] // check for syscall hooks + ldr x16, [tsk, #TSK_TI_FLAGS] // check for syscall hooks tst x16, #_TIF_SYSCALL_WORK b.ne __sys_trace cmp scno, sc_nr // check upper syscall limit diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 332e33193ccf..eaafb253bbfa 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -428,7 +428,8 @@ ENDPROC(__create_page_tables) __primary_switched: adrp x4, init_thread_union add sp, x4, #THREAD_SIZE - msr sp_el0, x4 // Save thread_info + adr_l x5, init_task + msr sp_el0, x5 // Save thread_info adr_l x8, vectors // load VBAR_EL1 with virtual msr vbar_el1, x8 // vector table address @@ -699,10 +700,10 @@ __secondary_switched: isb adr_l x0, secondary_data - ldr x0, [x0, #CPU_BOOT_STACK] // get secondary_data.stack - mov sp, x0 - and x0, x0, #~(THREAD_SIZE - 1) - msr sp_el0, x0 // save thread_info + ldr x1, [x0, #CPU_BOOT_STACK] // get secondary_data.stack + mov sp, x1 + ldr x2, [x0, #CPU_BOOT_TASK] + msr sp_el0, x2 mov x29, #0 b secondary_start_kernel ENDPROC(__secondary_switched) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index ec7b9c00effe..a98b743631c5 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -45,6 +45,7 @@ #include <linux/personality.h> #include <linux/notifier.h> #include <trace/events/power.h> +#include <linux/percpu.h> #include <asm/alternative.h> #include <asm/compat.h> @@ -322,6 +323,20 @@ void uao_thread_switch(struct task_struct *next) } /* + * We store our current task in sp_el0, which is clobbered by userspace. Keep a + * shadow copy so that we can restore this upon entry from userspace. + * + * This is *only* for exception entry from EL0, and is not valid until we + * __switch_to() a user task. + */ +DEFINE_PER_CPU(struct task_struct *, __entry_task); + +static void entry_task_switch(struct task_struct *next) +{ + __this_cpu_write(__entry_task, next); +} + +/* * Thread switching. */ struct task_struct *__switch_to(struct task_struct *prev, @@ -333,6 +348,7 @@ struct task_struct *__switch_to(struct task_struct *prev, tls_thread_switch(next); hw_breakpoint_thread_switch(next); contextidr_thread_switch(next); + entry_task_switch(next); uao_thread_switch(next); /* diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 6f42c68e457f..cb87234cfcf2 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -149,6 +149,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) * We need to tell the secondary core where to find its stack and the * page tables. */ + secondary_data.task = idle; secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; update_cpu_boot_status(CPU_MMU_OFF); __flush_dcache_area(&secondary_data, sizeof(secondary_data)); @@ -173,6 +174,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) pr_err("CPU%u: failed to boot: %d\n", cpu, ret); } + secondary_data.task = NULL; secondary_data.stack = NULL; status = READ_ONCE(secondary_data.status); if (ret && status) { |