diff options
Diffstat (limited to 'arch/xtensa/kernel/process.c')
| -rw-r--r-- | arch/xtensa/kernel/process.c | 248 |
1 files changed, 146 insertions, 102 deletions
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index 1c85323f01d7..94d43f44be13 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -17,6 +17,9 @@ #include <linux/errno.h> #include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/sched/task.h> +#include <linux/sched/task_stack.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/smp.h> @@ -24,6 +27,7 @@ #include <linux/unistd.h> #include <linux/ptrace.h> #include <linux/elf.h> +#include <linux/hw_breakpoint.h> #include <linux/init.h> #include <linux/prctl.h> #include <linux/init_task.h> @@ -33,8 +37,7 @@ #include <linux/slab.h> #include <linux/rcupdate.h> -#include <asm/pgtable.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/platform.h> @@ -43,60 +46,133 @@ #include <linux/atomic.h> #include <asm/asm-offsets.h> #include <asm/regs.h> +#include <asm/hw_breakpoint.h> +#include <asm/sections.h> +#include <asm/traps.h> extern void ret_from_fork(void); extern void ret_from_kernel_thread(void); -struct task_struct *current_set[NR_CPUS] = {&init_task, }; - void (*pm_power_off)(void) = NULL; EXPORT_SYMBOL(pm_power_off); +#ifdef CONFIG_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + #if XTENSA_HAVE_COPROCESSORS -void coprocessor_release_all(struct thread_info *ti) +void local_coprocessors_flush_release_all(void) { - unsigned long cpenable; - int i; + struct thread_info **coprocessor_owner; + struct thread_info *unique_owner[XCHAL_CP_MAX]; + int n = 0; + int i, j; - /* Make sure we don't switch tasks during this operation. */ + coprocessor_owner = this_cpu_ptr(&exc_table)->coprocessor_owner; + xtensa_set_sr(XCHAL_CP_MASK, cpenable); - preempt_disable(); + for (i = 0; i < XCHAL_CP_MAX; i++) { + struct thread_info *ti = coprocessor_owner[i]; - /* Walk through all cp owners and release it for the requested one. */ + if (ti) { + coprocessor_flush(ti, i); - cpenable = ti->cpenable; + for (j = 0; j < n; j++) + if (unique_owner[j] == ti) + break; + if (j == n) + unique_owner[n++] = ti; - for (i = 0; i < XCHAL_CP_MAX; i++) { - if (coprocessor_owner[i] == ti) { - coprocessor_owner[i] = 0; - cpenable &= ~(1 << i); + coprocessor_owner[i] = NULL; } } + for (i = 0; i < n; i++) { + /* pairs with memw (1) in fast_coprocessor and memw in switch_to */ + smp_wmb(); + unique_owner[i]->cpenable = 0; + } + xtensa_set_sr(0, cpenable); +} + +static void local_coprocessor_release_all(void *info) +{ + struct thread_info *ti = info; + struct thread_info **coprocessor_owner; + int i; - ti->cpenable = cpenable; - coprocessor_clear_cpenable(); + coprocessor_owner = this_cpu_ptr(&exc_table)->coprocessor_owner; - preempt_enable(); + /* Walk through all cp owners and release it for the requested one. */ + + for (i = 0; i < XCHAL_CP_MAX; i++) { + if (coprocessor_owner[i] == ti) + coprocessor_owner[i] = NULL; + } + /* pairs with memw (1) in fast_coprocessor and memw in switch_to */ + smp_wmb(); + ti->cpenable = 0; + if (ti == current_thread_info()) + xtensa_set_sr(0, cpenable); } -void coprocessor_flush_all(struct thread_info *ti) +void coprocessor_release_all(struct thread_info *ti) { - unsigned long cpenable; - int i; + if (ti->cpenable) { + /* pairs with memw (2) in fast_coprocessor */ + smp_rmb(); + smp_call_function_single(ti->cp_owner_cpu, + local_coprocessor_release_all, + ti, true); + } +} - preempt_disable(); +static void local_coprocessor_flush_all(void *info) +{ + struct thread_info *ti = info; + struct thread_info **coprocessor_owner; + unsigned long old_cpenable; + int i; - cpenable = ti->cpenable; + coprocessor_owner = this_cpu_ptr(&exc_table)->coprocessor_owner; + old_cpenable = xtensa_xsr(ti->cpenable, cpenable); for (i = 0; i < XCHAL_CP_MAX; i++) { - if ((cpenable & 1) != 0 && coprocessor_owner[i] == ti) + if (coprocessor_owner[i] == ti) coprocessor_flush(ti, i); - cpenable >>= 1; } + xtensa_set_sr(old_cpenable, cpenable); +} - preempt_enable(); +void coprocessor_flush_all(struct thread_info *ti) +{ + if (ti->cpenable) { + /* pairs with memw (2) in fast_coprocessor */ + smp_rmb(); + smp_call_function_single(ti->cp_owner_cpu, + local_coprocessor_flush_all, + ti, true); + } +} + +static void local_coprocessor_flush_release_all(void *info) +{ + local_coprocessor_flush_all(info); + local_coprocessor_release_all(info); +} + +void coprocessor_flush_release_all(struct thread_info *ti) +{ + if (ti->cpenable) { + /* pairs with memw (2) in fast_coprocessor */ + smp_rmb(); + smp_call_function_single(ti->cp_owner_cpu, + local_coprocessor_flush_release_all, + ti, true); + } } #endif @@ -108,15 +184,16 @@ void coprocessor_flush_all(struct thread_info *ti) void arch_cpu_idle(void) { platform_idle(); + raw_local_irq_disable(); } /* * This is called when the thread calls exit(). */ -void exit_thread(void) +void exit_thread(struct task_struct *tsk) { #if XTENSA_HAVE_COPROCESSORS - coprocessor_release_all(current_thread_info()); + coprocessor_release_all(task_thread_info(tsk)); #endif } @@ -128,9 +205,9 @@ void flush_thread(void) { #if XTENSA_HAVE_COPROCESSORS struct thread_info *ti = current_thread_info(); - coprocessor_flush_all(ti); - coprocessor_release_all(ti); + coprocessor_flush_release_all(ti); #endif + flush_ptrace_hw_breakpoint(current); } /* @@ -188,22 +265,31 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) * involved. Much simpler to just not copy those live frames across. */ -int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, - unsigned long thread_fn_arg, struct task_struct *p) +int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { + u64 clone_flags = args->flags; + unsigned long usp_thread_fn = args->stack; + unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); #if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS) struct thread_info *ti; #endif +#if defined(__XTENSA_WINDOWED_ABI__) /* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */ - *((int*)childregs - 3) = (unsigned long)childregs; - *((int*)childregs - 4) = 0; + SPILL_SLOT(childregs, 1) = (unsigned long)childregs; + SPILL_SLOT(childregs, 0) = 0; p->thread.sp = (unsigned long)childregs; +#elif defined(__XTENSA_CALL0_ABI__) + /* Reserve 16 bytes for the _switch_to stack frame. */ + p->thread.sp = (unsigned long)childregs - 16; +#else +#error Unsupported Xtensa ABI +#endif - if (!(p->flags & PF_KTHREAD)) { + if (!args->fn) { struct pt_regs *regs = current_pt_regs(); unsigned long usp = usp_thread_fn ? usp_thread_fn : regs->areg[1]; @@ -211,10 +297,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, p->thread.ra = MAKE_RA_FOR_CALL( (unsigned long)ret_from_fork, 0x1); - /* This does not copy all the regs. - * In a bout of brilliance or madness, - * ARs beyond a0-a15 exist past the end of the struct. - */ *childregs = *regs; childregs->areg[1] = usp; childregs->areg[2] = 0; @@ -244,24 +326,33 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, childregs->wmask = 1; childregs->windowstart = 1; childregs->windowbase = 0; - } else { - int len = childregs->wmask & ~0xf; - memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4], - ®s->areg[XCHAL_NUM_AREGS - len/4], len); } - /* The thread pointer is passed in the '4th argument' (= a5) */ if (clone_flags & CLONE_SETTLS) - childregs->threadptr = childregs->areg[5]; + childregs->threadptr = tls; } else { p->thread.ra = MAKE_RA_FOR_CALL( (unsigned long)ret_from_kernel_thread, 1); - /* pass parameters to ret_from_kernel_thread: - * a2 = thread_fn, a3 = thread_fn arg + /* pass parameters to ret_from_kernel_thread: */ +#if defined(__XTENSA_WINDOWED_ABI__) + /* + * a2 = thread_fn, a3 = thread_fn arg. + * Window underflow will load registers from the + * spill slots on the stack on return from _switch_to. + */ + SPILL_SLOT(childregs, 2) = (unsigned long)args->fn; + SPILL_SLOT(childregs, 3) = (unsigned long)args->fn_arg; +#elif defined(__XTENSA_CALL0_ABI__) + /* + * a12 = thread_fn, a13 = thread_fn arg. + * _switch_to epilogue will load registers from the stack. */ - *((int *)childregs - 1) = thread_fn_arg; - *((int *)childregs - 2) = usp_thread_fn; + ((unsigned long *)p->thread.sp)[0] = (unsigned long)args->fn; + ((unsigned long *)p->thread.sp)[1] = (unsigned long)args->fn_arg; +#else +#error Unsupported Xtensa ABI +#endif /* Childregs are only used when we're going to userspace * in which case start_thread will set them up. @@ -273,6 +364,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, ti->cpenable = 0; #endif + clear_ptrace_hw_breakpoint(p); + return 0; } @@ -281,17 +374,14 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, * These bracket the sleeping functions.. */ -unsigned long get_wchan(struct task_struct *p) +unsigned long __get_wchan(struct task_struct *p) { unsigned long sp, pc; unsigned long stack_page = (unsigned long) task_stack_page(p); int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) - return 0; - sp = p->thread.sp; - pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp); + pc = MAKE_PC_FROM_RA(p->thread.ra, _text); do { if (sp < stack_page + sizeof(struct task_struct) || @@ -303,54 +393,8 @@ unsigned long get_wchan(struct task_struct *p) /* Stack layout: sp-4: ra, sp-3: sp' */ - pc = MAKE_PC_FROM_RA(*(unsigned long*)sp - 4, sp); - sp = *(unsigned long *)sp - 3; + pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), _text); + sp = SPILL_SLOT(sp, 1); } while (count++ < 16); return 0; } - -/* - * xtensa_gregset_t and 'struct pt_regs' are vastly different formats - * of processor registers. Besides different ordering, - * xtensa_gregset_t contains non-live register information that - * 'struct pt_regs' does not. Exception handling (primarily) uses - * 'struct pt_regs'. Core files and ptrace use xtensa_gregset_t. - * - */ - -void xtensa_elf_core_copy_regs (xtensa_gregset_t *elfregs, struct pt_regs *regs) -{ - unsigned long wb, ws, wm; - int live, last; - - wb = regs->windowbase; - ws = regs->windowstart; - wm = regs->wmask; - ws = ((ws >> wb) | (ws << (WSBITS - wb))) & ((1 << WSBITS) - 1); - - /* Don't leak any random bits. */ - - memset(elfregs, 0, sizeof(*elfregs)); - - /* Note: PS.EXCM is not set while user task is running; its - * being set in regs->ps is for exception handling convenience. - */ - - elfregs->pc = regs->pc; - elfregs->ps = (regs->ps & ~(1 << PS_EXCM_BIT)); - elfregs->lbeg = regs->lbeg; - elfregs->lend = regs->lend; - elfregs->lcount = regs->lcount; - elfregs->sar = regs->sar; - elfregs->windowstart = ws; - - live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; - last = XCHAL_NUM_AREGS - (wm >> 4) * 4; - memcpy(elfregs->a, regs->areg, live * 4); - memcpy(elfregs->a + last, regs->areg + last, (wm >> 4) * 16); -} - -int dump_fpu(void) -{ - return 0; -} |