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MN10300: Save frame pointer in thread_info struct rather than global var

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Save the current exception frame pointer in the thread_info struct rather than
in a global variable as the latter makes SMP tricky, especially when preemption
is also enabled.

This also replaces __frame with current_frame() and rearranges header file
inclusions to make it all compile.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
This commit is contained in:
David Howells 2010-10-27 17:29:01 +01:00
parent a5e03ca2fd
commit 7c7fcf762e
15 changed files with 76 additions and 146 deletions
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56
arch/mn10300/include/asm/frame.inc
View File

@ -18,9 +18,7 @@
#ifndef __ASM_OFFSETS_H__
#include <asm/asm-offsets.h>
#endif
#ifdef CONFIG_SMP
#include <proc/smp-regs.h>
#endif
#include <asm/thread_info.h>
#define pi break
@ -40,27 +38,15 @@
movm [d2,d3,a2,a3,exreg0,exreg1,exother],(sp)
mov sp,fp # FRAME pointer in A3
add -12,sp # allow for calls to be made
#ifdef CONFIG_SMP
#ifdef CONFIG_PREEMPT /* FIXME */
mov epsw,d2
and ~EPSW_IE,epsw
#endif
mov (CPUID),a0
add a0,a0
add a0,a0
mov (___frame,a0),a1
mov a1,(REG_NEXT,fp)
mov fp,(___frame,a0)
#ifdef CONFIG_PREEMPT /* FIXME */
mov d2,epsw
#endif
#else /* CONFIG_SMP */
mov (__frame),a1
mov a1,(REG_NEXT,fp)
mov fp,(__frame)
#endif /* CONFIG_SMP */
and ~EPSW_FE,epsw # disable the FPU inside the kernel
# push the exception frame onto the front of the list
GET_THREAD_INFO a1
mov (TI_frame,a1),a0
mov a0,(REG_NEXT,fp)
mov fp,(TI_frame,a1)
# disable the FPU inside the kernel
and ~EPSW_FE,epsw
# we may be holding current in E2
#ifdef CONFIG_MN10300_CURRENT_IN_E2
@ -76,27 +62,11 @@
.macro RESTORE_ALL
# peel back the stack to the calling frame
# - this permits execve() to discard extra frames due to kernel syscalls
#ifdef CONFIG_SMP
#ifdef CONFIG_PREEMPT /* FIXME */
mov epsw,d2
and ~EPSW_IE,epsw
#endif
mov (CPUID),a0
add a0,a0
add a0,a0
mov (___frame,a0),fp
GET_THREAD_INFO a0
mov (TI_frame,a0),fp
mov fp,sp
mov (REG_NEXT,fp),d0 # userspace has regs->next == 0
mov d0,(___frame,a0)
#ifdef CONFIG_PREEMPT /* FIXME */
mov d2,epsw
#endif
#else /* CONFIG_SMP */
mov (__frame),fp
mov fp,sp
mov (REG_NEXT,fp),d0 # userspace has regs->next == 0
mov d0,(__frame)
#endif /* CONFIG_SMP */
mov (REG_NEXT,fp),d0
mov d0,(TI_frame,a0) # userspace has regs->next == 0
#ifndef CONFIG_MN10300_USING_JTAG
mov (REG_EPSW,fp),d0

6
arch/mn10300/include/asm/irq_regs.h
View File

@ -18,7 +18,11 @@
#define ARCH_HAS_OWN_IRQ_REGS
#ifndef __ASSEMBLY__
#define get_irq_regs() (__frame)
static inline __attribute__((const))
struct pt_regs *get_irq_regs(void)
{
return current_frame();
}
#endif
#endif /* _ASM_IRQ_REGS_H */

1
arch/mn10300/include/asm/pgalloc.h
View File

@ -11,7 +11,6 @@
#ifndef _ASM_PGALLOC_H
#define _ASM_PGALLOC_H
#include <asm/processor.h>
#include <asm/page.h>
#include <linux/threads.h>
#include <linux/mm.h> /* for struct page */

46
arch/mn10300/include/asm/processor.h
View File

@ -13,10 +13,13 @@
#ifndef _ASM_PROCESSOR_H
#define _ASM_PROCESSOR_H
#include <linux/threads.h>
#include <linux/thread_info.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/cpu-regs.h>
#include <linux/threads.h>
#include <asm/uaccess.h>
#include <asm/current.h>
/* Forward declaration, a strange C thing */
struct task_struct;
@ -83,10 +86,6 @@ extern void dodgy_tsc(void);
*/
#define TASK_UNMAPPED_BASE 0x30000000
typedef struct {
unsigned long seg;
} mm_segment_t;
struct fpu_state_struct {
unsigned long fs[32]; /* fpu registers */
unsigned long fpcr; /* fpu control register */
@ -99,7 +98,6 @@ struct thread_struct {
unsigned long a3; /* kernel FP */
unsigned long wchan;
unsigned long usp;
struct pt_regs *frame;
unsigned long fpu_flags;
#define THREAD_USING_FPU 0x00000001 /* T if this task is using the FPU */
#define THREAD_HAS_FPU 0x00000002 /* T if this task owns the FPU right now */
@ -113,7 +111,6 @@ struct thread_struct {
.sp = 0, \
.a3 = 0, \
.wchan = 0, \
.frame = NULL, \
}
#define INIT_MMAP \
@ -125,27 +122,20 @@ struct thread_struct {
* - need to discard the frame stacked by the kernel thread invoking the execve
* syscall (see RESTORE_ALL macro)
*/
#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) /* FIXME */
#define start_thread(regs, new_pc, new_sp) do { \
int cpu; \
preempt_disable(); \
cpu = CPUID; \
set_fs(USER_DS); \
___frame[cpu] = current->thread.uregs; \
___frame[cpu]->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;\
___frame[cpu]->pc = new_pc; \
___frame[cpu]->sp = new_sp; \
preempt_enable(); \
} while (0)
#else /* CONFIG_SMP && CONFIG_PREEMPT */
#define start_thread(regs, new_pc, new_sp) do { \
set_fs(USER_DS); \
__frame = current->thread.uregs; \
__frame->epsw = EPSW_nSL | EPSW_IE | EPSW_IM; \
__frame->pc = new_pc; \
__frame->sp = new_sp; \
} while (0)
#endif /* CONFIG_SMP && CONFIG_PREEMPT */
static inline void start_thread(struct pt_regs *regs,
unsigned long new_pc, unsigned long new_sp)
{
struct thread_info *ti = current_thread_info();
struct pt_regs *frame0;
set_fs(USER_DS);
frame0 = thread_info_to_uregs(ti);
frame0->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;
frame0->pc = new_pc;
frame0->sp = new_sp;
ti->frame = frame0;
}
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);

6
arch/mn10300/include/asm/ptrace.h
View File

@ -86,12 +86,6 @@ struct pt_regs {
#ifdef __KERNEL__
#ifdef CONFIG_SMP
extern struct pt_regs *___frame[]; /* current frame pointer */
#else
extern struct pt_regs *__frame; /* current frame pointer */
#endif
#define user_mode(regs) (((regs)->epsw & EPSW_nSL) == EPSW_nSL)
#define instruction_pointer(regs) ((regs)->pc)
#define user_stack_pointer(regs) ((regs)->sp)

13
arch/mn10300/include/asm/smp.h
View File

@ -93,19 +93,6 @@ extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_PREEMPT /* FIXME */
#define __frame \
({ \
struct pt_regs *f; \
preempt_disable(); \
f = ___frame[CPUID]; \
preempt_enable(); \
f; \
})
#else
#define __frame ___frame[CPUID]
#endif
#endif /* __ASSEMBLY__ */
#else /* CONFIG_SMP */
#ifndef __ASSEMBLY__

18
arch/mn10300/include/asm/thread_info.h
View File

@ -16,10 +16,6 @@
#include <asm/page.h>
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#endif
#define PREEMPT_ACTIVE 0x10000000
#ifdef CONFIG_4KSTACKS
@ -38,10 +34,14 @@
* must also be changed
*/
#ifndef __ASSEMBLY__
typedef struct {
unsigned long seg;
} mm_segment_t;
struct thread_info {
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
struct pt_regs *frame; /* current exception frame */
unsigned long flags; /* low level flags */
__u32 cpu; /* current CPU */
__s32 preempt_count; /* 0 => preemptable, <0 => BUG */
@ -55,6 +55,10 @@ struct thread_info {
__u8 supervisor_stack[0];
};
#define thread_info_to_uregs(ti) \
((struct pt_regs *) \
((unsigned long)ti + THREAD_SIZE - sizeof(struct pt_regs)))
#else /* !__ASSEMBLY__ */
#ifndef __ASM_OFFSETS_H__
@ -102,6 +106,12 @@ struct thread_info *current_thread_info(void)
return ti;
}
static inline __attribute__((const))
struct pt_regs *current_frame(void)
{
return current_thread_info()->frame;
}
/* how to get the current stack pointer from C */
static inline unsigned long current_stack_pointer(void)
{

4
arch/mn10300/include/asm/uaccess.h
View File

@ -14,9 +14,8 @@
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <linux/thread_info.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/errno.h>
#define VERIFY_READ 0
@ -29,7 +28,6 @@
*
* For historical reasons, these macros are grossly misnamed.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#define KERNEL_XDS MAKE_MM_SEG(0xBFFFFFFF)

2
arch/mn10300/kernel/asm-offsets.c
View File

@ -23,6 +23,7 @@ void foo(void)
OFFSET(TI_task, thread_info, task);
OFFSET(TI_exec_domain, thread_info, exec_domain);
OFFSET(TI_frame, thread_info, frame);
OFFSET(TI_flags, thread_info, flags);
OFFSET(TI_cpu, thread_info, cpu);
OFFSET(TI_preempt_count, thread_info, preempt_count);
@ -66,7 +67,6 @@ void foo(void)
OFFSET(THREAD_SP, thread_struct, sp);
OFFSET(THREAD_A3, thread_struct, a3);
OFFSET(THREAD_USP, thread_struct, usp);
OFFSET(THREAD_FRAME, thread_struct, frame);
#ifdef CONFIG_FPU
OFFSET(THREAD_FPU_FLAGS, thread_struct, fpu_flags);
OFFSET(THREAD_FPU_STATE, thread_struct, fpu_state);

2
arch/mn10300/kernel/mn10300-watchdog.c
View File

@ -122,7 +122,7 @@ void __init watchdog_go(void)
static void watchdog_dump_register(void *dummy)
{
printk(KERN_ERR "--- Register Dump (CPU%d) ---\n", CPUID);
show_registers(__frame);
show_registers(current_frame());
}
#endif

20
arch/mn10300/kernel/process.c
View File

@ -228,6 +228,7 @@ int copy_thread(unsigned long clone_flags,
unsigned long c_usp, unsigned long ustk_size,
struct task_struct *p, struct pt_regs *kregs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *c_uregs, *c_kregs, *uregs;
unsigned long c_ksp;
@ -248,7 +249,7 @@ int copy_thread(unsigned long clone_flags,
/* the new TLS pointer is passed in as arg #5 to sys_clone() */
if (clone_flags & CLONE_SETTLS)
c_uregs->e2 = __frame->d3;
c_uregs->e2 = current_frame()->d3;
/* set up the return kernel frame if called from kernel_thread() */
c_kregs = c_uregs;
@ -266,7 +267,7 @@ int copy_thread(unsigned long clone_flags,
}
/* set up things up so the scheduler can start the new task */
p->thread.frame = c_kregs;
ti->frame = c_kregs;
p->thread.a3 = (unsigned long) c_kregs;
p->thread.sp = c_ksp;
p->thread.pc = (unsigned long) ret_from_fork;
@ -278,25 +279,26 @@ int copy_thread(unsigned long clone_flags,
/*
* clone a process
* - tlsptr is retrieved by copy_thread() from __frame->d3
* - tlsptr is retrieved by copy_thread() from current_frame()->d3
*/
asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
int __user *parent_tidptr, int __user *child_tidptr,
int __user *tlsptr)
{
return do_fork(clone_flags, newsp ?: __frame->sp, __frame, 0,
parent_tidptr, child_tidptr);
return do_fork(clone_flags, newsp ?: current_frame()->sp,
current_frame(), 0, parent_tidptr, child_tidptr);
}
asmlinkage long sys_fork(void)
{
return do_fork(SIGCHLD, __frame->sp, __frame, 0, NULL, NULL);
return do_fork(SIGCHLD, current_frame()->sp,
current_frame(), 0, NULL, NULL);
}
asmlinkage long sys_vfork(void)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, __frame->sp, __frame,
0, NULL, NULL);
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, current_frame()->sp,
current_frame(), 0, NULL, NULL);
}
asmlinkage long sys_execve(const char __user *name,
@ -310,7 +312,7 @@ asmlinkage long sys_execve(const char __user *name,
error = PTR_ERR(filename);
if (IS_ERR(filename))
return error;
error = do_execve(filename, argv, envp, __frame);
error = do_execve(filename, argv, envp, current_frame());
putname(filename);
return error;
}

20
arch/mn10300/kernel/signal.c
View File

@ -91,7 +91,7 @@ asmlinkage long sys_sigaction(int sig,
*/
asmlinkage long sys_sigaltstack(const stack_t __user *uss, stack_t *uoss)
{
return do_sigaltstack(uss, uoss, __frame->sp);
return do_sigaltstack(uss, uoss, current_frame()->sp);
}
/*
@ -156,10 +156,11 @@ badframe:
*/
asmlinkage long sys_sigreturn(void)
{
struct sigframe __user *frame = (struct sigframe __user *) __frame->sp;
struct sigframe __user *frame;
sigset_t set;
long d0;
frame = (struct sigframe __user *) current_frame()->sp;
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask))
@ -176,7 +177,7 @@ asmlinkage long sys_sigreturn(void)
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(__frame, &frame->sc, &d0))
if (restore_sigcontext(current_frame(), &frame->sc, &d0))
goto badframe;
return d0;
@ -191,11 +192,11 @@ badframe:
*/
asmlinkage long sys_rt_sigreturn(void)
{
struct rt_sigframe __user *frame =
(struct rt_sigframe __user *) __frame->sp;
struct rt_sigframe __user *frame;
sigset_t set;
unsigned long d0;
long d0;
frame = (struct rt_sigframe __user *) current_frame()->sp;
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
@ -207,10 +208,11 @@ asmlinkage long sys_rt_sigreturn(void)
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(__frame, &frame->uc.uc_mcontext, &d0))
if (restore_sigcontext(current_frame(), &frame->uc.uc_mcontext, &d0))
goto badframe;
if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT)
if (do_sigaltstack(&frame->uc.uc_stack, NULL, current_frame()->sp) ==
-EFAULT)
goto badframe;
return d0;
@ -572,7 +574,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(__frame);
tracehook_notify_resume(current_frame());
if (current->replacement_session_keyring)
key_replace_session_keyring();
}

18
arch/mn10300/kernel/switch_to.S
View File

@ -38,15 +38,6 @@ ENTRY(__switch_to)
mov d1,a1
# save prev context
#ifdef CONFIG_SMP
mov (CPUID),a2
add a2,a2
add a2,a2
mov (___frame,a2),d0
#else /* CONFIG_SMP */
mov (__frame),d0
#endif /* CONFIG_SMP */
mov d0,(THREAD_FRAME,a0)
mov __switch_back,d0
mov d0,(THREAD_PC,a0)
mov sp,a2
@ -68,15 +59,6 @@ ENTRY(__switch_to)
mov a2,e2
#endif
mov (THREAD_FRAME,a1),a2
#ifdef CONFIG_SMP
mov (CPUID),a0
add a0,a0
add a0,a0
mov a2,(___frame,a0)
#else /* CONFIG_SMP */
mov a2,(__frame)
#endif /* CONFIG_SMP */
mov (THREAD_PC,a1),a2
mov d2,d0 # for ret_from_fork
mov d0,a0 # for __switch_to

8
arch/mn10300/kernel/traps.c
View File

@ -45,14 +45,6 @@
#error "INTERRUPT_VECTOR_BASE not aligned to 16MiB boundary!"
#endif
#ifdef CONFIG_SMP
struct pt_regs *___frame[NR_CPUS]; /* current frame pointer */
EXPORT_SYMBOL(___frame);
#else /* CONFIG_SMP */
struct pt_regs *__frame; /* current frame pointer */
EXPORT_SYMBOL(__frame);
#endif /* CONFIG_SMP */
int kstack_depth_to_print = 24;
spinlock_t die_lock = __SPIN_LOCK_UNLOCKED(die_lock);

2
mm/maccess.c
View File

@ -1,9 +1,9 @@
/*
* Access kernel memory without faulting.
*/
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
/**
* probe_kernel_read(): safely attempt to read from a location