[PATCH] (21/22) task_thread_info - part 4/4

From: Al Viro
Date: Thu Aug 25 2005 - 00:23:49 EST

partially pulled from m68k CVS; switches m68k handling of thread flags to
usual bitmap, which allows to unify most of the thread flag helpers. After
that only task_thread_info(), stack_end() and setup_thread_info() are
conditional on __HAVE_THREAD_FUNCTIONS.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
----
diff -urN RC13-rc7-m68k/arch/m68k/fpsp040/skeleton.S RC13-rc7-m68k-flags/arch/m68k/fpsp040/skeleton.S
--- RC13-rc7-m68k/arch/m68k/fpsp040/skeleton.S 2005-06-17 15:48:29.000000000 -0400
+++ RC13-rc7-m68k-flags/arch/m68k/fpsp040/skeleton.S 2005-08-25 00:54:20.000000000 -0400
@@ -381,10 +381,8 @@
.Lnotkern:
SAVE_ALL_INT
GET_CURRENT(%d0)
- tstb %curptr@(TASK_NEEDRESCHED)
- jne ret_from_exception | deliver signals,
- | reschedule etc..
- RESTORE_ALL
+ | deliver signals, reschedule etc..
+ jra ret_from_exception

|
| mem_write --- write to user or supervisor address space
diff -urN RC13-rc7-m68k/arch/m68k/ifpsp060/iskeleton.S RC13-rc7-m68k-flags/arch/m68k/ifpsp060/iskeleton.S
--- RC13-rc7-m68k/arch/m68k/ifpsp060/iskeleton.S 2005-06-17 15:48:29.000000000 -0400
+++ RC13-rc7-m68k-flags/arch/m68k/ifpsp060/iskeleton.S 2005-08-25 00:54:20.000000000 -0400
@@ -75,10 +75,8 @@
.Lnotkern:
SAVE_ALL_INT
GET_CURRENT(%d0)
- tstb %curptr@(TASK_NEEDRESCHED)
- jne ret_from_exception | deliver signals,
- | reschedule etc..
- RESTORE_ALL
+ | deliver signals, reschedule etc..
+ jra ret_from_exception

|
| _060_real_chk():
diff -urN RC13-rc7-m68k/arch/m68k/kernel/asm-offsets.c RC13-rc7-m68k-flags/arch/m68k/kernel/asm-offsets.c
--- RC13-rc7-m68k/arch/m68k/kernel/asm-offsets.c 2005-08-25 00:54:19.000000000 -0400
+++ RC13-rc7-m68k-flags/arch/m68k/kernel/asm-offsets.c 2005-08-25 00:54:20.000000000 -0400
@@ -25,11 +25,6 @@
DEFINE(TASK_STATE, offsetof(struct task_struct, state));
DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags));
DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace));
- DEFINE(TASK_WORK, offsetof(struct task_struct, thread.work));
- DEFINE(TASK_NEEDRESCHED, offsetof(struct task_struct, thread.work.need_resched));
- DEFINE(TASK_SYSCALL_TRACE, offsetof(struct task_struct, thread.work.syscall_trace));
- DEFINE(TASK_SIGPENDING, offsetof(struct task_struct, thread.work.sigpending));
- DEFINE(TASK_NOTIFY_RESUME, offsetof(struct task_struct, thread.work.notify_resume));
DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));
DEFINE(TASK_INFO, offsetof(struct task_struct, thread.info));
DEFINE(TASK_MM, offsetof(struct task_struct, mm));
@@ -48,7 +43,7 @@

/* offsets into the thread_info struct */
DEFINE(TINFO_PREEMPT, offsetof(struct thread_info, preempt_count));
- DEFINE(HARDIRQ_SHIFT, HARDIRQ_SHIFT);
+ DEFINE(TINFO_FLAGS, offsetof(struct thread_info, flags));

/* offsets into the pt_regs */
DEFINE(PT_D0, offsetof(struct pt_regs, d0));
diff -urN RC13-rc7-m68k/arch/m68k/kernel/entry.S RC13-rc7-m68k-flags/arch/m68k/kernel/entry.S
--- RC13-rc7-m68k/arch/m68k/kernel/entry.S 2005-06-17 15:48:29.000000000 -0400
+++ RC13-rc7-m68k-flags/arch/m68k/kernel/entry.S 2005-08-25 00:54:20.000000000 -0400
@@ -44,9 +44,7 @@

#include <asm/offsets.h>

-.globl system_call, buserr, trap
-.globl resume, ret_from_exception
-.globl ret_from_signal
+.globl system_call, buserr, trap, resume
.globl inthandler, sys_call_table
.globl sys_fork, sys_clone, sys_vfork
.globl ret_from_interrupt, bad_interrupt
@@ -58,7 +56,7 @@
movel %sp,%sp@- | stack frame pointer argument
bsrl buserr_c
addql #4,%sp
- jra ret_from_exception
+ jra .Lret_from_exception

ENTRY(trap)
SAVE_ALL_INT
@@ -66,7 +64,7 @@
movel %sp,%sp@- | stack frame pointer argument
bsrl trap_c
addql #4,%sp
- jra ret_from_exception
+ jra .Lret_from_exception

| After a fork we jump here directly from resume,
| so that %d1 contains the previous task
@@ -75,30 +73,31 @@
movel %d1,%sp@-
jsr schedule_tail
addql #4,%sp
- jra ret_from_exception
+ jra .Lret_from_exception

-badsys:
- movel #-ENOSYS,%sp@(PT_D0)
- jra ret_from_exception
-
-do_trace:
+do_trace_entry:
movel #-ENOSYS,%sp@(PT_D0) | needed for strace
subql #4,%sp
SAVE_SWITCH_STACK
jbsr syscall_trace
RESTORE_SWITCH_STACK
addql #4,%sp
- movel %sp@(PT_ORIG_D0),%d1
- movel #-ENOSYS,%d0
- cmpl #NR_syscalls,%d1
- jcc 1f
- jbsr @(sys_call_table,%d1:l:4)@(0)
-1: movel %d0,%sp@(PT_D0) | save the return value
- subql #4,%sp | dummy return address
+ movel %sp@(PT_ORIG_D0),%d0
+ cmpl #NR_syscalls,%d0
+ jcs syscall
+badsys:
+ movel #-ENOSYS,%sp@(PT_D0)
+ jra ret_from_syscall
+
+do_trace_exit:
+ subql #4,%sp
SAVE_SWITCH_STACK
jbsr syscall_trace
+ RESTORE_SWITCH_STACK
+ addql #4,%sp
+ jra .Lret_from_exception

-ret_from_signal:
+ENTRY(ret_from_signal)
RESTORE_SWITCH_STACK
addql #4,%sp
/* on 68040 complete pending writebacks if any */
@@ -111,7 +110,7 @@
addql #4,%sp
1:
#endif
- jra ret_from_exception
+ jra .Lret_from_exception

ENTRY(system_call)
SAVE_ALL_SYS
@@ -120,30 +119,34 @@
| save top of frame
movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)

- tstb %curptr@(TASK_SYSCALL_TRACE)
- jne do_trace
+ | syscall trace?
+ tstb %curptr@(TASK_INFO+TINFO_FLAGS+2)
+ jmi do_trace_entry
cmpl #NR_syscalls,%d0
jcc badsys
+syscall:
jbsr @(sys_call_table,%d0:l:4)@(0)
movel %d0,%sp@(PT_D0) | save the return value
-
+ret_from_syscall:
|oriw #0x0700,%sr
- movel %curptr@(TASK_WORK),%d0
+ movew %curptr@(TASK_INFO+TINFO_FLAGS+2),%d0
jne syscall_exit_work
1: RESTORE_ALL

syscall_exit_work:
btst #5,%sp@(PT_SR) | check if returning to kernel
bnes 1b | if so, skip resched, signals
- tstw %d0
- jeq do_signal_return
- tstb %d0
- jne do_delayed_trace
-
+ lslw #1,%d0
+ jcs do_trace_exit
+ jmi do_delayed_trace
+ lslw #8,%d0
+ jmi do_signal_return
pea resume_userspace
- jmp schedule
+ jra schedule
+

-ret_from_exception:
+ENTRY(ret_from_exception)
+.Lret_from_exception:
btst #5,%sp@(PT_SR) | check if returning to kernel
bnes 1f | if so, skip resched, signals
| only allow interrupts when we are really the last one on the
@@ -152,19 +155,18 @@
andw #ALLOWINT,%sr

resume_userspace:
- movel %curptr@(TASK_WORK),%d0
- lsrl #8,%d0
+ moveb %curptr@(TASK_INFO+TINFO_FLAGS+3),%d0
jne exit_work
1: RESTORE_ALL

exit_work:
| save top of frame
movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
- tstb %d0
- jeq do_signal_return
-
+ lslb #1,%d0
+ jmi do_signal_return
pea resume_userspace
- jmp schedule
+ jra schedule
+

do_signal_return:
|andw #ALLOWINT,%sr
@@ -254,7 +256,7 @@

/* check if we need to do software interrupts */
tstl irq_stat+CPUSTAT_SOFTIRQ_PENDING
- jeq ret_from_exception
+ jeq .Lret_from_exception
pea ret_from_exception
jra do_softirq

diff -urN RC13-rc7-m68k/arch/m68k/kernel/ptrace.c RC13-rc7-m68k-flags/arch/m68k/kernel/ptrace.c
--- RC13-rc7-m68k/arch/m68k/kernel/ptrace.c 2005-06-17 15:48:29.000000000 -0400
+++ RC13-rc7-m68k-flags/arch/m68k/kernel/ptrace.c 2005-08-25 00:54:20.000000000 -0400
@@ -103,18 +103,22 @@
}

/*
- * Called by kernel/ptrace.c when detaching..
- *
* Make sure the single step bit is not set.
*/
-void ptrace_disable(struct task_struct *child)
+static inline void singlestep_disable(struct task_struct *child)
{
- unsigned long tmp;
- /* make sure the single step bit is not set. */
- tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
+ unsigned long tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
put_reg(child, PT_SR, tmp);
- child->thread.work.delayed_trace = 0;
- child->thread.work.syscall_trace = 0;
+ clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ singlestep_disable(child);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}

asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
@@ -248,46 +252,33 @@
break;

case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
- case PTRACE_CONT: { /* restart after signal. */
- long tmp;
-
+ case PTRACE_CONT: /* restart after signal. */
ret = -EIO;
if (!valid_signal(data))
break;
- if (request == PTRACE_SYSCALL) {
- child->thread.work.syscall_trace = ~0;
- } else {
- child->thread.work.syscall_trace = 0;
- }
+ if (request == PTRACE_SYSCALL)
+ set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ else
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
child->exit_code = data;
- /* make sure the single step bit is not set. */
- tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
- put_reg(child, PT_SR, tmp);
- child->thread.work.delayed_trace = 0;
+ singlestep_disable(child);
wake_up_process(child);
ret = 0;
break;
- }

/*
* make the child exit. Best I can do is send it a sigkill.
* perhaps it should be put in the status that it wants to
* exit.
*/
- case PTRACE_KILL: {
- long tmp;
-
+ case PTRACE_KILL:
ret = 0;
if (child->exit_state == EXIT_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
- /* make sure the single step bit is not set. */
- tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
- put_reg(child, PT_SR, tmp);
- child->thread.work.delayed_trace = 0;
+ singlestep_disable(child);
wake_up_process(child);
break;
- }

case PTRACE_SINGLESTEP: { /* set the trap flag. */
long tmp;
@@ -295,10 +286,10 @@
ret = -EIO;
if (!valid_signal(data))
break;
- child->thread.work.syscall_trace = 0;
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
put_reg(child, PT_SR, tmp);
- child->thread.work.delayed_trace = 1;
+ set_tsk_thread_flag(child, TIF_DELAYED_TRACE);

child->exit_code = data;
/* give it a chance to run. */
@@ -377,9 +368,6 @@

asmlinkage void syscall_trace(void)
{
- if (!current->thread.work.delayed_trace &&
- !current->thread.work.syscall_trace)
- return;
ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
? 0x80 : 0));
/*
diff -urN RC13-rc7-m68k/include/asm-m68k/processor.h RC13-rc7-m68k-flags/include/asm-m68k/processor.h
--- RC13-rc7-m68k/include/asm-m68k/processor.h 2005-08-25 00:54:19.000000000 -0400
+++ RC13-rc7-m68k-flags/include/asm-m68k/processor.h 2005-08-25 00:54:20.000000000 -0400
@@ -56,17 +56,6 @@
#endif
#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)

-struct task_work {
- unsigned char sigpending;
- unsigned char notify_resume; /* request for notification on
- userspace execution resumption */
- char need_resched;
- unsigned char delayed_trace; /* single step a syscall */
- unsigned char syscall_trace; /* count of syscall interceptors */
- unsigned char memdie; /* task was selected to be killed */
- unsigned char pad[2];
-};
-
struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long usp; /* user stack pointer */
@@ -79,7 +68,6 @@
unsigned long fp[8*3];
unsigned long fpcntl[3]; /* fp control regs */
unsigned char fpstate[FPSTATESIZE]; /* floating point state */
- struct task_work work;
struct thread_info info;
};

diff -urN RC13-rc7-m68k/include/asm-m68k/thread_info.h RC13-rc7-m68k-flags/include/asm-m68k/thread_info.h
--- RC13-rc7-m68k/include/asm-m68k/thread_info.h 2005-08-25 00:54:19.000000000 -0400
+++ RC13-rc7-m68k-flags/include/asm-m68k/thread_info.h 2005-08-25 00:54:20.000000000 -0400
@@ -6,6 +6,7 @@

struct thread_info {
struct task_struct *task; /* main task structure */
+ unsigned long flags;
struct exec_domain *exec_domain; /* execution domain */
int preempt_count; /* 0 => preemptable, <0 => BUG */
__u32 cpu; /* should always be 0 on m68k */
@@ -42,80 +43,18 @@

#define __HAVE_THREAD_FUNCTIONS

-#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
-#define TIF_DELAYED_TRACE 1 /* single step a syscall */
-#define TIF_NOTIFY_RESUME 2 /* resumption notification requested */
-#define TIF_SIGPENDING 3 /* signal pending */
-#define TIF_NEED_RESCHED 4 /* rescheduling necessary */
-#define TIF_MEMDIE 5
-
-extern int thread_flag_fixme(void);
-
#define setup_thread_info(p, ti) do (ti)->task = p; while(0)

#define end_of_stack(p) ((unsigned long *)(p)->thread_info + 1)

-/*
- * flag set/clear/test wrappers
- * - pass TIF_xxxx constants to these functions
+/* entry.S relies on these definitions!
+ * bits 0-7 are tested at every exception exit
+ * bits 8-15 are also tested at syscall exit
*/
-
-#define __set_tsk_thread_flag(tsk, flag, val) ({ \
- switch (flag) { \
- case TIF_SIGPENDING: \
- tsk->thread.work.sigpending = val; \
- break; \
- case TIF_NEED_RESCHED: \
- tsk->thread.work.need_resched = val; \
- break; \
- case TIF_SYSCALL_TRACE: \
- tsk->thread.work.syscall_trace = val; \
- break; \
- case TIF_MEMDIE: \
- tsk->thread.work.memdie = val; \
- break; \
- default: \
- thread_flag_fixme(); \
- } \
-})
-
-#define __get_tsk_thread_flag(tsk, flag) ({ \
- int ___res; \
- switch (flag) { \
- case TIF_SIGPENDING: \
- ___res = tsk->thread.work.sigpending; \
- break; \
- case TIF_NEED_RESCHED: \
- ___res = tsk->thread.work.need_resched; \
- break; \
- case TIF_SYSCALL_TRACE: \
- ___res = tsk->thread.work.syscall_trace;\
- break; \
- case TIF_MEMDIE: \
- ___res = tsk->thread.work.memdie;\
- break; \
- default: \
- ___res = thread_flag_fixme(); \
- } \
- ___res; \
-})
-
-#define __get_set_tsk_thread_flag(tsk, flag, val) ({ \
- int __res = __get_tsk_thread_flag(tsk, flag); \
- __set_tsk_thread_flag(tsk, flag, val); \
- __res; \
-})
-
-#define set_tsk_thread_flag(tsk, flag) __set_tsk_thread_flag(tsk, flag, ~0)
-#define clear_tsk_thread_flag(tsk, flag) __set_tsk_thread_flag(tsk, flag, 0)
-#define test_and_set_tsk_thread_flag(tsk, flag) __get_set_tsk_thread_flag(tsk, flag, ~0)
-#define test_tsk_thread_flag(tsk, flag) __get_tsk_thread_flag(tsk, flag)
-
-#define set_thread_flag(flag) set_tsk_thread_flag(current, flag)
-#define clear_thread_flag(flag) clear_tsk_thread_flag(current, flag)
-#define test_thread_flag(flag) test_tsk_thread_flag(current, flag)
-
-#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED)
-#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED)
+#define TIF_SIGPENDING 6 /* signal pending */
+#define TIF_NEED_RESCHED 7 /* rescheduling necessary */
+#define TIF_DELAYED_TRACE 14 /* single step a syscall */
+#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
+#define TIF_MEMDIE 16

#endif /* _ASM_M68K_THREAD_INFO_H */
diff -urN RC13-rc7-m68k/include/linux/sched.h RC13-rc7-m68k-flags/include/linux/sched.h
--- RC13-rc7-m68k/include/linux/sched.h 2005-08-25 00:54:18.000000000 -0400
+++ RC13-rc7-m68k-flags/include/linux/sched.h 2005-08-25 00:54:20.000000000 -0400
@@ -1150,6 +1150,8 @@
return (unsigned long *)(p->thread_info + 1);
}

+#endif
+
/* set thread flags in other task's structures
* - see asm/thread_info.h for TIF_xxxx flags available
*/
@@ -1178,8 +1180,6 @@
return test_ti_thread_flag(task_thread_info(tsk), flag);
}

-#endif
-
static inline void set_tsk_need_resched(struct task_struct *tsk)
{
set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
diff -urN RC13-rc7-m68k/include/linux/thread_info.h RC13-rc7-m68k-flags/include/linux/thread_info.h
--- RC13-rc7-m68k/include/linux/thread_info.h 2005-08-25 00:54:18.000000000 -0400
+++ RC13-rc7-m68k-flags/include/linux/thread_info.h 2005-08-25 00:54:20.000000000 -0400
@@ -22,37 +22,11 @@

#ifdef __KERNEL__

-#ifndef __HAVE_THREAD_FUNCTIONS
/*
* flag set/clear/test wrappers
* - pass TIF_xxxx constants to these functions
*/

-static inline void set_thread_flag(int flag)
-{
- set_bit(flag,&current_thread_info()->flags);
-}
-
-static inline void clear_thread_flag(int flag)
-{
- clear_bit(flag,&current_thread_info()->flags);
-}
-
-static inline int test_and_set_thread_flag(int flag)
-{
- return test_and_set_bit(flag,&current_thread_info()->flags);
-}
-
-static inline int test_and_clear_thread_flag(int flag)
-{
- return test_and_clear_bit(flag,&current_thread_info()->flags);
-}
-
-static inline int test_thread_flag(int flag)
-{
- return test_bit(flag,&current_thread_info()->flags);
-}
-
static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
{
set_bit(flag,&ti->flags);
@@ -78,17 +52,20 @@
return test_bit(flag,&ti->flags);
}

-static inline void set_need_resched(void)
-{
- set_thread_flag(TIF_NEED_RESCHED);
-}
+#define set_thread_flag(flag) \
+ set_ti_thread_flag(current_thread_info(), flag)
+#define clear_thread_flag(flag) \
+ clear_ti_thread_flag(current_thread_info(), flag)
+#define test_and_set_thread_flag(flag) \
+ test_and_set_ti_thread_flag(current_thread_info(), flag)
+#define test_and_clear_thread_flag(flag) \
+ test_and_clear_ti_thread_flag(current_thread_info(), flag)
+#define test_thread_flag(flag) \
+ test_ti_thread_flag(current_thread_info(), flag)

-static inline void clear_need_resched(void)
-{
- clear_thread_flag(TIF_NEED_RESCHED);
-}
+#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED)
+#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED)

#endif
-#endif

#endif /* _LINUX_THREAD_INFO_H */
-
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