diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index bf24ab188921..212f34b2a58e 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -107,6 +107,7 @@ config S390 select ARCH_SUPPORTS_NUMA_BALANCING select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_WANTS_DYNAMIC_TASK_STRUCT select ARCH_WANTS_PROT_NUMA_PROT_NONE select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT diff --git a/arch/s390/include/asm/fpu/types.h b/arch/s390/include/asm/fpu/types.h index 14a8b0c14f87..fe937c9b6471 100644 --- a/arch/s390/include/asm/fpu/types.h +++ b/arch/s390/include/asm/fpu/types.h @@ -11,11 +11,13 @@ #include struct fpu { - __u32 fpc; /* Floating-point control */ + __u32 fpc; /* Floating-point control */ + void *regs; /* Pointer to the current save area */ union { - void *regs; - freg_t *fprs; /* Floating-point register save area */ - __vector128 *vxrs; /* Vector register save area */ + /* Floating-point register save area */ + freg_t fprs[__NUM_FPRS]; + /* Vector register save area */ + __vector128 vxrs[__NUM_VXRS]; }; }; diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index d6fd22ea270d..332f4f7dc8d3 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -105,7 +105,6 @@ typedef struct { * Thread structure */ struct thread_struct { - struct fpu fpu; /* FP and VX register save area */ unsigned int acrs[NUM_ACRS]; unsigned long ksp; /* kernel stack pointer */ mm_segment_t mm_segment; @@ -120,6 +119,11 @@ struct thread_struct { /* cpu runtime instrumentation */ struct runtime_instr_cb *ri_cb; unsigned char trap_tdb[256]; /* Transaction abort diagnose block */ + /* + * Warning: 'fpu' is dynamically-sized. It *MUST* be at + * the end. + */ + struct fpu fpu; /* FP and VX register save area */ }; /* Flag to disable transactions. */ @@ -155,10 +159,9 @@ struct stack_frame { #define ARCH_MIN_TASKALIGN 8 -extern __vector128 init_task_fpu_regs[__NUM_VXRS]; #define INIT_THREAD { \ .ksp = sizeof(init_stack) + (unsigned long) &init_stack, \ - .fpu.regs = (void *)&init_task_fpu_regs, \ + .fpu.regs = (void *) init_task.thread.fpu.fprs, \ } /* diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 2bba7df4ac51..adb346b70166 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -37,9 +37,6 @@ asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); -/* FPU save area for the init task */ -__vector128 init_task_fpu_regs[__NUM_VXRS] __init_task_data; - /* * Return saved PC of a blocked thread. used in kernel/sched. * resume in entry.S does not create a new stack frame, it @@ -85,35 +82,19 @@ void release_thread(struct task_struct *dead_task) void arch_release_task_struct(struct task_struct *tsk) { - /* Free either the floating-point or the vector register save area */ - kfree(tsk->thread.fpu.regs); } int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { - size_t fpu_regs_size; - - *dst = *src; - - /* - * If the vector extension is available, it is enabled for all tasks, - * and, thus, the FPU register save area must be allocated accordingly. - */ - fpu_regs_size = MACHINE_HAS_VX ? sizeof(__vector128) * __NUM_VXRS - : sizeof(freg_t) * __NUM_FPRS; - dst->thread.fpu.regs = kzalloc(fpu_regs_size, GFP_KERNEL|__GFP_REPEAT); - if (!dst->thread.fpu.regs) - return -ENOMEM; - /* * Save the floating-point or vector register state of the current * task and set the CIF_FPU flag to lazy restore the FPU register * state when returning to user space. */ save_fpu_regs(); - dst->thread.fpu.fpc = current->thread.fpu.fpc; - memcpy(dst->thread.fpu.regs, current->thread.fpu.regs, fpu_regs_size); + memcpy(dst, src, arch_task_struct_size); + dst->thread.fpu.regs = dst->thread.fpu.fprs; return 0; } diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index d3f9688f26b5..f31939147ccd 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -808,6 +808,22 @@ static void __init setup_randomness(void) free_page((unsigned long) vmms); } +/* + * Find the correct size for the task_struct. This depends on + * the size of the struct fpu at the end of the thread_struct + * which is embedded in the task_struct. + */ +static void __init setup_task_size(void) +{ + int task_size = sizeof(struct task_struct); + + if (!MACHINE_HAS_VX) { + task_size -= sizeof(__vector128) * __NUM_VXRS; + task_size += sizeof(freg_t) * __NUM_FPRS; + } + arch_task_struct_size = task_size; +} + /* * Setup function called from init/main.c just after the banner * was printed. @@ -846,6 +862,7 @@ void __init setup_arch(char **cmdline_p) os_info_init(); setup_ipl(); + setup_task_size(); /* Do some memory reservations *before* memory is added to memblock */ reserve_memory_end();