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-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/fpu/types.h10
-rw-r--r--arch/s390/include/asm/processor.h9
-rw-r--r--arch/s390/kernel/process.c23
-rw-r--r--arch/s390/kernel/setup.c17
5 files changed, 32 insertions, 28 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index bf24ab1..212f34b 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 14a8b0c..fe937c9 100644
--- a/arch/s390/include/asm/fpu/types.h
+++ b/arch/s390/include/asm/fpu/types.h
@@ -11,11 +11,13 @@
#include <asm/sigcontext.h>
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 d6fd22e..332f4f7 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 2bba7df..adb346b 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 d3f9688..f319391 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -809,6 +809,22 @@ static void __init setup_randomness(void)
}
/*
+ * 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();
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