OOM fixes 5/5

From: Andrea Arcangeli
Date: Fri Jan 21 2005 - 01:02:07 EST

From: Andrea Arcangeli <andrea@xxxxxxx>
Subject: Convert the unsafe signed (16bit) used_math to a safe and optimal PF_USED_MATH

On Sat, Dec 25, 2004 at 04:24:30AM +0100, Andrea Arcangeli wrote:
> Here it is the first part. This makes memdie a TIF_MEMDIE. It's

And here is the final incremental part converting ->used_math to
PF_USED_MATH.

I might have broken arm, see the very first change in the patch to
asm-offsets.c, rest looks ok at first glance.

If you want used_math to return 0 or 1 (instead of 0 or PF_USED_MATH),
just s/!!// in the below patch and place !! in sched.h::*used_math()
accordingly after applying the patch, it should work just fine. Using !!
only when necessary as the below is optimal.

Signed-off-by: Andrea Arcangeli <andrea@xxxxxxx>

--- mainline-5/arch/arm26/kernel/asm-offsets.c.orig 2003-07-17 01:52:38.000000000 +0200
+++ mainline-5/arch/arm26/kernel/asm-offsets.c 2005-01-21 06:20:01.999885640 +0100
@@ -42,7 +42,6 @@

int main(void)
{
- DEFINE(TSK_USED_MATH, offsetof(struct task_struct, used_math));
DEFINE(TSK_ACTIVE_MM, offsetof(struct task_struct, active_mm));
BLANK();
DEFINE(VMA_VM_MM, offsetof(struct vm_area_struct, vm_mm));
--- mainline-5/arch/arm26/kernel/process.c.orig 2005-01-15 20:44:48.000000000 +0100
+++ mainline-5/arch/arm26/kernel/process.c 2005-01-21 06:20:02.013883512 +0100
@@ -271,7 +271,7 @@ void flush_thread(void)
memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
memset(&thread->fpstate, 0, sizeof(union fp_state));

- current->used_math = 0;
+ clear_used_math();
}

void release_thread(struct task_struct *dead_task)
@@ -305,7 +305,7 @@ copy_thread(int nr, unsigned long clone_
int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
{
struct thread_info *thread = current_thread_info();
- int used_math = current->used_math;
+ int used_math = !!used_math();

if (used_math)
memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
--- mainline-5/arch/arm26/kernel/ptrace.c.orig 2005-01-04 01:13:09.000000000 +0100
+++ mainline-5/arch/arm26/kernel/ptrace.c 2005-01-21 06:20:02.018882752 +0100
@@ -540,7 +540,7 @@ static int ptrace_getfpregs(struct task_
*/
static int ptrace_setfpregs(struct task_struct *tsk, void *ufp)
{
- tsk->used_math = 1;
+ set_stopped_child_used_math(tsk);
return copy_from_user(&tsk->thread_info->fpstate, ufp,
sizeof(struct user_fp)) ? -EFAULT : 0;
}
--- mainline-5/arch/i386/kernel/cpu/common.c.orig 2005-01-15 20:44:49.000000000 +0100
+++ mainline-5/arch/i386/kernel/cpu/common.c 2005-01-21 06:20:02.027881384 +0100
@@ -629,6 +629,6 @@ void __init cpu_init (void)
* Force FPU initialization:
*/
current_thread_info()->status = 0;
- current->used_math = 0;
+ clear_used_math();
mxcsr_feature_mask_init();
}
--- mainline-5/arch/i386/kernel/i387.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/i386/kernel/i387.c 2005-01-21 06:20:02.040879408 +0100
@@ -60,7 +60,8 @@ void init_fpu(struct task_struct *tsk)
tsk->thread.i387.fsave.twd = 0xffffffffu;
tsk->thread.i387.fsave.fos = 0xffff0000u;
}
- tsk->used_math = 1;
+ /* only the device not available exception or ptrace can call init_fpu */
+ set_stopped_child_used_math(tsk);
}

/*
@@ -331,13 +332,13 @@ static int save_i387_fxsave( struct _fps

int save_i387( struct _fpstate __user *buf )
{
- if ( !current->used_math )
+ if ( !used_math() )
return 0;

/* This will cause a "finit" to be triggered by the next
* attempted FPU operation by the 'current' process.
*/
- current->used_math = 0;
+ clear_used_math();

if ( HAVE_HWFP ) {
if ( cpu_has_fxsr ) {
@@ -383,7 +384,7 @@ int restore_i387( struct _fpstate __user
} else {
err = restore_i387_soft( &current->thread.i387.soft, buf );
}
- current->used_math = 1;
+ set_used_math();
return err;
}

@@ -507,7 +508,7 @@ int dump_fpu( struct pt_regs *regs, stru
int fpvalid;
struct task_struct *tsk = current;

- fpvalid = tsk->used_math;
+ fpvalid = !!used_math();
if ( fpvalid ) {
unlazy_fpu( tsk );
if ( cpu_has_fxsr ) {
@@ -522,7 +523,7 @@ int dump_fpu( struct pt_regs *regs, stru

int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
{
- int fpvalid = tsk->used_math;
+ int fpvalid = !!tsk_used_math(tsk);

if (fpvalid) {
if (tsk == current)
@@ -537,7 +538,7 @@ int dump_task_fpu(struct task_struct *ts

int dump_task_extended_fpu(struct task_struct *tsk, struct user_fxsr_struct *fpu)
{
- int fpvalid = tsk->used_math && cpu_has_fxsr;
+ int fpvalid = tsk_used_math(tsk) && cpu_has_fxsr;

if (fpvalid) {
if (tsk == current)
--- mainline-5/arch/i386/kernel/process.c.orig 2005-01-15 20:44:49.000000000 +0100
+++ mainline-5/arch/i386/kernel/process.c 2005-01-21 06:20:02.049878040 +0100
@@ -351,7 +351,7 @@ void flush_thread(void)
* Forget coprocessor state..
*/
clear_fpu(tsk);
- tsk->used_math = 0;
+ clear_used_math();
}

void release_thread(struct task_struct *dead_task)
--- mainline-5/arch/i386/kernel/ptrace.c.orig 2005-01-15 20:44:49.000000000 +0100
+++ mainline-5/arch/i386/kernel/ptrace.c 2005-01-21 06:20:02.052877584 +0100
@@ -592,7 +592,7 @@ asmlinkage int sys_ptrace(long request,
break;
}
ret = 0;
- if (!child->used_math)
+ if (!tsk_used_math(child))
init_fpu(child);
get_fpregs((struct user_i387_struct __user *)data, child);
break;
@@ -604,7 +604,7 @@ asmlinkage int sys_ptrace(long request,
ret = -EIO;
break;
}
- child->used_math = 1;
+ set_stopped_child_used_math(child);
set_fpregs(child, (struct user_i387_struct __user *)data);
ret = 0;
break;
@@ -616,7 +616,7 @@ asmlinkage int sys_ptrace(long request,
ret = -EIO;
break;
}
- if (!child->used_math)
+ if (!tsk_used_math(child))
init_fpu(child);
ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
break;
@@ -628,7 +628,7 @@ asmlinkage int sys_ptrace(long request,
ret = -EIO;
break;
}
- child->used_math = 1;
+ set_stopped_child_used_math(child);
ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
break;
}
--- mainline-5/arch/i386/kernel/traps.c.orig 2005-01-15 20:44:49.000000000 +0100
+++ mainline-5/arch/i386/kernel/traps.c 2005-01-21 06:20:02.054877280 +0100
@@ -911,7 +911,7 @@ asmlinkage void math_state_restore(struc
struct task_struct *tsk = thread->task;

clts(); /* Allow maths ops (or we recurse) */
- if (!tsk->used_math)
+ if (!tsk_used_math(tsk))
init_fpu(tsk);
restore_fpu(tsk);
thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
--- mainline-5/arch/i386/math-emu/fpu_entry.c.orig 2004-08-25 02:47:49.000000000 +0200
+++ mainline-5/arch/i386/math-emu/fpu_entry.c 2005-01-21 06:20:02.066875456 +0100
@@ -155,10 +155,10 @@ asmlinkage void math_emulate(long arg)
RE_ENTRANT_CHECK_ON;
#endif /* RE_ENTRANT_CHECKING */

- if (!current->used_math)
+ if (!used_math())
{
finit();
- current->used_math = 1;
+ set_used_math();
}

SETUP_DATA_AREA(arg);
--- mainline-5/arch/ia64/ia32/elfcore32.h.orig 2005-01-04 01:13:09.000000000 +0100
+++ mainline-5/arch/ia64/ia32/elfcore32.h 2005-01-21 06:20:02.077873784 +0100
@@ -106,7 +106,7 @@ elf_core_copy_task_fpregs(struct task_st
struct ia32_user_i387_struct *fpstate = (void*)fpu;
mm_segment_t old_fs;

- if (!tsk->used_math)
+ if (!tsk_used_math(tsk))
return 0;

old_fs = get_fs();
@@ -124,7 +124,7 @@ elf_core_copy_task_xfpregs(struct task_s
struct ia32_user_fxsr_struct *fpxstate = (void*) xfpu;
mm_segment_t old_fs;

- if (!tsk->used_math)
+ if (!tsk_used_math(tsk))
return 0;

old_fs = get_fs();
--- mainline-5/arch/mips/kernel/irixsig.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/mips/kernel/irixsig.c 2005-01-21 06:20:02.085872568 +0100
@@ -99,7 +99,7 @@ static void setup_irix_frame(struct k_si
__put_user((u64) regs->hi, &ctx->hi);
__put_user((u64) regs->lo, &ctx->lo);
__put_user((u64) regs->cp0_epc, &ctx->pc);
- __put_user(current->used_math, &ctx->usedfp);
+ __put_user(!!used_math(), &ctx->usedfp);
__put_user((u64) regs->cp0_cause, &ctx->cp0_cause);
__put_user((u64) regs->cp0_badvaddr, &ctx->cp0_badvaddr);

@@ -725,7 +725,7 @@ asmlinkage int irix_getcontext(struct pt
__put_user(regs->cp0_epc, &ctx->regs[35]);

flags = 0x0f;
- if(!current->used_math) {
+ if(!used_math()) {
flags &= ~(0x08);
} else {
/* XXX wheee... */
--- mainline-5/arch/mips/kernel/process.c.orig 2005-01-04 01:13:10.000000000 +0100
+++ mainline-5/arch/mips/kernel/process.c 2005-01-21 06:20:02.093871352 +0100
@@ -76,7 +76,7 @@ void start_thread(struct pt_regs * regs,
#endif
status |= KU_USER;
regs->cp0_status = status;
- current->used_math = 0;
+ clear_used_math();
lose_fpu();
regs->cp0_epc = pc;
regs->regs[29] = sp;
--- mainline-5/arch/mips/kernel/ptrace.c.orig 2005-01-04 01:13:10.000000000 +0100
+++ mainline-5/arch/mips/kernel/ptrace.c 2005-01-21 06:20:02.094871200 +0100
@@ -119,7 +119,7 @@ asmlinkage int sys_ptrace(long request,
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
- if (child->used_math) {
+ if (tsk_used_math(child)) {
fpureg_t *fregs = get_fpu_regs(child);

#ifdef CONFIG_MIPS32
@@ -205,7 +205,7 @@ asmlinkage int sys_ptrace(long request,
case FPR_BASE ... FPR_BASE + 31: {
fpureg_t *fregs = get_fpu_regs(child);

- if (!child->used_math) {
+ if (!tsk_used_math(child)) {
/* FP not yet used */
memset(&child->thread.fpu.hard, ~0,
sizeof(child->thread.fpu.hard));
--- mainline-5/arch/mips/kernel/ptrace32.c.orig 2005-01-04 01:13:10.000000000 +0100
+++ mainline-5/arch/mips/kernel/ptrace32.c 2005-01-21 06:20:02.096870896 +0100
@@ -112,7 +112,7 @@ asmlinkage int sys32_ptrace(int request,
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
- if (child->used_math) {
+ if (tsk_used_math(child)) {
fpureg_t *fregs = get_fpu_regs(child);

/*
@@ -193,7 +193,7 @@ asmlinkage int sys32_ptrace(int request,
case FPR_BASE ... FPR_BASE + 31: {
fpureg_t *fregs = get_fpu_regs(child);

- if (!child->used_math) {
+ if (!tsk_used_math(child)) {
/* FP not yet used */
memset(&child->thread.fpu.hard, ~0,
sizeof(child->thread.fpu.hard));
--- mainline-5/arch/mips/kernel/signal.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/mips/kernel/signal.c 2005-01-21 06:20:02.098870592 +0100
@@ -178,11 +178,11 @@ asmlinkage int restore_sigcontext(struct
restore_gp_reg(31);
#undef restore_gp_reg

- err |= __get_user(current->used_math, &sc->sc_used_math);
+ err |= __get_user(!!used_math(), &sc->sc_used_math);

preempt_disable();

- if (current->used_math) {
+ if (used_math()) {
/* restore fpu context if we have used it before */
own_fpu();
err |= restore_fp_context(sc);
@@ -323,9 +323,9 @@ inline int setup_sigcontext(struct pt_re
err |= __put_user(regs->cp0_cause, &sc->sc_cause);
err |= __put_user(regs->cp0_badvaddr, &sc->sc_badvaddr);

- err |= __put_user(current->used_math, &sc->sc_used_math);
+ err |= __put_user(!!used_math(), &sc->sc_used_math);

- if (!current->used_math)
+ if (!used_math())
goto out;

/*
--- mainline-5/arch/mips/kernel/signal32.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/mips/kernel/signal32.c 2005-01-21 06:20:02.099870440 +0100
@@ -361,11 +361,11 @@ static asmlinkage int restore_sigcontext
restore_gp_reg(31);
#undef restore_gp_reg

- err |= __get_user(current->used_math, &sc->sc_used_math);
+ err |= __get_user(!!used_math(), &sc->sc_used_math);

preempt_disable();

- if (current->used_math) {
+ if (used_math()) {
/* restore fpu context if we have used it before */
own_fpu();
err |= restore_fp_context32(sc);
@@ -552,9 +552,9 @@ static inline int setup_sigcontext32(str
err |= __put_user(regs->cp0_cause, &sc->sc_cause);
err |= __put_user(regs->cp0_badvaddr, &sc->sc_badvaddr);

- err |= __put_user(current->used_math, &sc->sc_used_math);
+ err |= __put_user(!!used_math(), &sc->sc_used_math);

- if (!current->used_math)
+ if (!used_math())
goto out;

/*
--- mainline-5/arch/mips/kernel/traps.c.orig 2005-01-04 01:13:10.000000000 +0100
+++ mainline-5/arch/mips/kernel/traps.c 2005-01-21 06:20:02.105869528 +0100
@@ -655,11 +655,11 @@ asmlinkage void do_cpu(struct pt_regs *r
preempt_disable();

own_fpu();
- if (current->used_math) { /* Using the FPU again. */
+ if (used_math()) { /* Using the FPU again. */
restore_fp(current);
} else { /* First time FPU user. */
init_fpu();
- current->used_math = 1;
+ set_used_math();
}

if (!cpu_has_fpu) {
--- mainline-5/arch/s390/kernel/process.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/s390/kernel/process.c 2005-01-21 06:20:02.120867248 +0100
@@ -215,8 +215,7 @@ void exit_thread(void)

void flush_thread(void)
{
-
- current->used_math = 0;
+ clear_used_math();
clear_tsk_thread_flag(current, TIF_USEDFPU);
}

--- mainline-5/arch/s390/kernel/setup.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/s390/kernel/setup.c 2005-01-21 06:20:02.129865880 +0100
@@ -96,7 +96,7 @@ void __devinit cpu_init (void)
* Force FPU initialization:
*/
clear_thread_flag(TIF_USEDFPU);
- current->used_math = 0;
+ clear_used_math();

atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
--- mainline-5/arch/sh/kernel/cpu/sh4/fpu.c.orig 2004-02-20 17:26:36.000000000 +0100
+++ mainline-5/arch/sh/kernel/cpu/sh4/fpu.c 2005-01-21 06:20:02.139864360 +0100
@@ -323,13 +323,13 @@ do_fpu_state_restore(unsigned long r4, u
return;
}

- if (tsk->used_math) {
+ if (used_math()) {
/* Using the FPU again. */
restore_fpu(tsk);
} else {
/* First time FPU user. */
fpu_init();
- tsk->used_math = 1;
+ set_used_math();
}
set_tsk_thread_flag(tsk, TIF_USEDFPU);
}
--- mainline-5/arch/sh/kernel/cpu/init.c.orig 2005-01-04 01:13:11.000000000 +0100
+++ mainline-5/arch/sh/kernel/cpu/init.c 2005-01-21 06:20:02.150862688 +0100
@@ -194,7 +194,7 @@ asmlinkage void __init sh_cpu_init(void)
/* FPU initialization */
if ((cpu_data->flags & CPU_HAS_FPU)) {
clear_thread_flag(TIF_USEDFPU);
- current->used_math = 0;
+ clear_used_math();
}

#ifdef CONFIG_SH_DSP
--- mainline-5/arch/sh/kernel/process.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/sh/kernel/process.c 2005-01-21 06:20:02.159861320 +0100
@@ -208,7 +208,7 @@ void flush_thread(void)

/* Forget lazy FPU state */
clear_fpu(tsk, regs);
- tsk->used_math = 0;
+ clear_used_math();
#endif
}

@@ -225,7 +225,7 @@ int dump_fpu(struct pt_regs *regs, elf_f
#if defined(CONFIG_SH_FPU)
struct task_struct *tsk = current;

- fpvalid = tsk->used_math;
+ fpvalid = !!tsk_used_math(tsk);
if (fpvalid) {
unlazy_fpu(tsk, regs);
memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
@@ -260,7 +260,7 @@ dump_task_fpu (struct task_struct *tsk,
int fpvalid = 0;

#if defined(CONFIG_SH_FPU)
- fpvalid = tsk->used_math;
+ fpvalid = !!tsk_used_math(tsk);
if (fpvalid) {
struct pt_regs *regs = (struct pt_regs *)
((unsigned long)tsk->thread_info
@@ -286,7 +286,7 @@ int copy_thread(int nr, unsigned long cl

unlazy_fpu(tsk, regs);
p->thread.fpu = tsk->thread.fpu;
- p->used_math = tsk->used_math;
+ copy_to_stopped_child_used_math(p);
#endif

childregs = ((struct pt_regs *)
--- mainline-5/arch/sh/kernel/ptrace.c.orig 2005-01-04 01:13:11.000000000 +0100
+++ mainline-5/arch/sh/kernel/ptrace.c 2005-01-21 06:20:02.168859952 +0100
@@ -150,7 +150,7 @@ asmlinkage int sys_ptrace(long request,
tmp = get_stack_long(child, addr);
else if (addr >= (long) &dummy->fpu &&
addr < (long) &dummy->u_fpvalid) {
- if (!child->used_math) {
+ if (!tsk_used_math(child)) {
if (addr == (long)&dummy->fpu.fpscr)
tmp = FPSCR_INIT;
else
@@ -159,7 +159,7 @@ asmlinkage int sys_ptrace(long request,
tmp = ((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2];
} else if (addr == (long) &dummy->u_fpvalid)
- tmp = child->used_math;
+ tmp = !!tsk_used_math(child);
else
tmp = 0;
ret = put_user(tmp, (unsigned long *)data);
@@ -185,12 +185,12 @@ asmlinkage int sys_ptrace(long request,
ret = put_stack_long(child, addr, data);
else if (addr >= (long) &dummy->fpu &&
addr < (long) &dummy->u_fpvalid) {
- child->used_math = 1;
+ set_stopped_child_used_math(child);
((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2] = data;
ret = 0;
} else if (addr == (long) &dummy->u_fpvalid) {
- child->used_math = data?1:0;
+ conditional_stopped_child_used_math(data, child);
ret = 0;
}
break;
--- mainline-5/arch/sh/kernel/signal.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/sh/kernel/signal.c 2005-01-21 06:20:02.170859648 +0100
@@ -162,7 +162,7 @@ static inline int restore_sigcontext_fpu
if (!(cpu_data->flags & CPU_HAS_FPU))
return 0;

- tsk->used_math = 1;
+ set_used_math();
return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0],
sizeof(long)*(16*2+2));
}
@@ -175,7 +175,7 @@ static inline int save_sigcontext_fpu(st
if (!(cpu_data->flags & CPU_HAS_FPU))
return 0;

- if (!tsk->used_math) {
+ if (!used_math()) {
__put_user(0, &sc->sc_ownedfp);
return 0;
}
@@ -185,7 +185,7 @@ static inline int save_sigcontext_fpu(st
/* This will cause a "finit" to be triggered by the next
attempted FPU operation by the 'current' process.
*/
- tsk->used_math = 0;
+ clear_used_math();

unlazy_fpu(tsk, regs);
return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard,
@@ -219,7 +219,7 @@ restore_sigcontext(struct pt_regs *regs,

regs->sr |= SR_FD; /* Release FPU */
clear_fpu(tsk, regs);
- tsk->used_math = 0;
+ clear_used_math();
__get_user (owned_fp, &sc->sc_ownedfp);
if (owned_fp)
err |= restore_sigcontext_fpu(sc);
--- mainline-5/arch/sh64/kernel/fpu.c.orig 2004-08-25 02:47:49.000000000 +0200
+++ mainline-5/arch/sh64/kernel/fpu.c 2005-01-21 06:20:02.182857824 +0100
@@ -158,12 +158,12 @@ do_fpu_state_restore(unsigned long ex, s
fpsave(&last_task_used_math->thread.fpu.hard);
}
last_task_used_math = current;
- if (current->used_math) {
+ if (used_math()) {
fpload(&current->thread.fpu.hard);
} else {
/* First time FPU user. */
fpload(&init_fpuregs.hard);
- current->used_math = 1;
+ set_used_math();
}
release_fpu();
}
--- mainline-5/arch/sh64/kernel/process.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/sh64/kernel/process.c 2005-01-21 06:20:02.195855848 +0100
@@ -688,7 +688,7 @@ void flush_thread(void)
last_task_used_math = NULL;
}
/* Force FPU state to be reinitialised after exec */
- current->used_math = 0;
+ clear_used_math();
#endif

/* if we are a kernel thread, about to change to user thread,
@@ -713,7 +713,7 @@ int dump_fpu(struct pt_regs *regs, elf_f
int fpvalid;
struct task_struct *tsk = current;

- fpvalid = tsk->used_math;
+ fpvalid = !!tsk_used_math(tsk);
if (fpvalid) {
if (current == last_task_used_math) {
grab_fpu();
--- mainline-5/arch/sh64/kernel/ptrace.c.orig 2005-01-04 01:13:11.000000000 +0100
+++ mainline-5/arch/sh64/kernel/ptrace.c 2005-01-21 06:20:02.202854784 +0100
@@ -63,7 +63,7 @@ get_fpu_long(struct task_struct *task, u
struct pt_regs *regs;
regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;

- if (!task->used_math) {
+ if (!tsk_used_math(task)) {
if (addr == offsetof(struct user_fpu_struct, fpscr)) {
tmp = FPSCR_INIT;
} else {
@@ -105,9 +105,9 @@ put_fpu_long(struct task_struct *task, u

regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;

- if (!task->used_math) {
+ if (!tsk_used_math(task)) {
fpinit(&task->thread.fpu.hard);
- task->used_math = 1;
+ set_stopped_child_used_math(task);
} else if (last_task_used_math == task) {
grab_fpu();
fpsave(&task->thread.fpu.hard);
@@ -187,7 +187,7 @@ asmlinkage int sys_ptrace(long request,
(addr < offsetof(struct user, u_fpvalid))) {
tmp = get_fpu_long(child, addr - offsetof(struct user, fpu));
} else if (addr == offsetof(struct user, u_fpvalid)) {
- tmp = child->used_math;
+ tmp = !!tsk_used_math(child);
} else {
break;
}
--- mainline-5/arch/sh64/kernel/signal.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/sh64/kernel/signal.c 2005-01-21 06:20:02.204854480 +0100
@@ -186,7 +186,7 @@ restore_sigcontext_fpu(struct pt_regs *r
int fpvalid;

err |= __get_user (fpvalid, &sc->sc_fpvalid);
- current->used_math = fpvalid;
+ conditional_used_math(fpvalid);
if (! fpvalid)
return err;

@@ -207,7 +207,7 @@ setup_sigcontext_fpu(struct pt_regs *reg
int err = 0;
int fpvalid;

- fpvalid = current->used_math;
+ fpvalid = !!used_math();
err |= __put_user(fpvalid, &sc->sc_fpvalid);
if (! fpvalid)
return err;
@@ -222,7 +222,7 @@ setup_sigcontext_fpu(struct pt_regs *reg

err |= __copy_to_user(&sc->sc_fpregs[0], &current->thread.fpu.hard,
(sizeof(long long) * 32) + (sizeof(int) * 1));
- current->used_math = 0;
+ clear_used_math();

return err;
}
--- mainline-5/arch/sparc/kernel/process.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/sparc/kernel/process.c 2005-01-21 06:20:02.219852200 +0100
@@ -599,7 +599,7 @@ void dump_thread(struct pt_regs * regs,
*/
int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
{
- if (current->used_math == 0) {
+ if (used_math()) {
memset(fpregs, 0, sizeof(*fpregs));
fpregs->pr_q_entrysize = 8;
return 1;
--- mainline-5/arch/sparc/kernel/signal.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/sparc/kernel/signal.c 2005-01-21 06:20:02.225851288 +0100
@@ -202,7 +202,7 @@ restore_fpu_state(struct pt_regs *regs,
regs->psr &= ~PSR_EF;
}
#endif
- current->used_math = 1;
+ set_used_math();
clear_tsk_thread_flag(current, TIF_USEDFPU);

if (verify_area(VERIFY_READ, fpu, sizeof(*fpu)))
@@ -584,7 +584,7 @@ save_fpu_state(struct pt_regs *regs, __s
&current->thread.fpqueue[0],
((sizeof(unsigned long) +
(sizeof(unsigned long *)))*16));
- current->used_math = 0;
+ clear_used_math();
return err;
}

@@ -599,7 +599,7 @@ new_setup_frame(struct k_sigaction *ka,
synchronize_user_stack();

sigframe_size = NF_ALIGNEDSZ;
- if (!current->used_math)
+ if (!used_math())
sigframe_size -= sizeof(__siginfo_fpu_t);

sf = (struct new_signal_frame __user *)
@@ -616,7 +616,7 @@ new_setup_frame(struct k_sigaction *ka,

err |= __put_user(0, &sf->extra_size);

- if (current->used_math) {
+ if (used_math()) {
err |= save_fpu_state(regs, &sf->fpu_state);
err |= __put_user(&sf->fpu_state, &sf->fpu_save);
} else {
@@ -677,7 +677,7 @@ new_setup_rt_frame(struct k_sigaction *k

synchronize_user_stack();
sigframe_size = RT_ALIGNEDSZ;
- if (!current->used_math)
+ if (!used_math())
sigframe_size -= sizeof(__siginfo_fpu_t);
sf = (struct rt_signal_frame __user *)
get_sigframe(&ka->sa, regs, sigframe_size);
@@ -690,7 +690,7 @@ new_setup_rt_frame(struct k_sigaction *k
err |= __put_user(regs->npc, &sf->regs.npc);
err |= __put_user(regs->y, &sf->regs.y);
psr = regs->psr;
- if (current->used_math)
+ if (used_math())
psr |= PSR_EF;
err |= __put_user(psr, &sf->regs.psr);
err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
--- mainline-5/arch/sparc/kernel/traps.c.orig 2004-08-25 02:47:49.000000000 +0200
+++ mainline-5/arch/sparc/kernel/traps.c 2005-01-21 06:20:02.233850072 +0100
@@ -246,17 +246,17 @@ void do_fpd_trap(struct pt_regs *regs, u
&fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
}
last_task_used_math = current;
- if(current->used_math) {
+ if(used_math()) {
fpload(&current->thread.float_regs[0], &current->thread.fsr);
} else {
/* Set initial sane state. */
fpload(&init_fregs[0], &init_fsr);
- current->used_math = 1;
+ set_used_math();
}
#else
- if(!current->used_math) {
+ if(!used_math()) {
fpload(&init_fregs[0], &init_fsr);
- current->used_math = 1;
+ set_used_math();
} else {
fpload(&current->thread.float_regs[0], &current->thread.fsr);
}
--- mainline-5/arch/x86_64/ia32/fpu32.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/x86_64/ia32/fpu32.c 2005-01-21 06:20:02.246848096 +0100
@@ -157,7 +157,7 @@ int restore_i387_ia32(struct task_struct
sizeof(struct i387_fxsave_struct)))
return -1;
tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
- tsk->used_math = 1;
+ set_stopped_child_used_math(tsk);
}
return convert_fxsr_from_user(&tsk->thread.i387.fxsave, buf);
}
--- mainline-5/arch/x86_64/ia32/ia32_binfmt.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/x86_64/ia32/ia32_binfmt.c 2005-01-21 06:20:02.255846728 +0100
@@ -214,7 +214,7 @@ elf_core_copy_task_fpregs(struct task_st
struct _fpstate_ia32 *fpstate = (void*)fpu;
mm_segment_t oldfs = get_fs();

- if (!tsk->used_math)
+ if (!tsk_used_math(tsk))
return 0;
if (!regs)
regs = (struct pt_regs *)tsk->thread.rsp0;
@@ -235,7 +235,7 @@ static inline int
elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
{
struct pt_regs *regs = ((struct pt_regs *)(t->thread.rsp0))-1;
- if (!t->used_math)
+ if (!tsk_used_math(t))
return 0;
if (t == current)
unlazy_fpu(t);
--- mainline-5/arch/x86_64/ia32/ia32_signal.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/x86_64/ia32/ia32_signal.c 2005-01-21 06:20:02.256846576 +0100
@@ -389,7 +389,7 @@ ia32_setup_sigcontext(struct sigcontext_
if (tmp < 0)
err = -EFAULT;
else {
- current->used_math = 0;
+ clear_used_math();
stts();
err |= __put_user((u32)(u64)(tmp ? fpstate : NULL), &sc->fpstate);
}
--- mainline-5/arch/x86_64/ia32/ptrace32.c.orig 2005-01-04 01:13:11.000000000 +0100
+++ mainline-5/arch/x86_64/ia32/ptrace32.c 2005-01-21 06:20:02.272844144 +0100
@@ -358,7 +358,7 @@ asmlinkage long sys32_ptrace(long reques
break;
/* no checking to be bug-to-bug compatible with i386 */
__copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u));
- child->used_math = 1;
+ set_stopped_child_used_math(child);
child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
ret = 0;
break;
--- mainline-5/arch/x86_64/kernel/i387.c.orig 2004-08-25 02:47:33.000000000 +0200
+++ mainline-5/arch/x86_64/kernel/i387.c 2005-01-21 06:20:02.282842624 +0100
@@ -57,12 +57,12 @@ void __init fpu_init(void)
mxcsr_feature_mask_init();
/* clean state in init */
current_thread_info()->status = 0;
- current->used_math = 0;
+ clear_used_math();
}

void init_fpu(struct task_struct *child)
{
- if (child->used_math) {
+ if (tsk_used_math(child)) {
if (child == current)
unlazy_fpu(child);
return;
@@ -70,7 +70,8 @@ void init_fpu(struct task_struct *child)
memset(&child->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
child->thread.i387.fxsave.cwd = 0x37f;
child->thread.i387.fxsave.mxcsr = 0x1f80;
- child->used_math = 1;
+ /* only the device not available exception or ptrace can call init_fpu */
+ set_stopped_child_used_math(child);
}

/*
@@ -91,9 +92,9 @@ int save_i387(struct _fpstate __user *bu
if ((unsigned long)buf % 16)
printk("save_i387: bad fpstate %p\n",buf);

- if (!tsk->used_math)
+ if (!used_math())
return 0;
- tsk->used_math = 0; /* trigger finit */
+ clear_used_math(); /* trigger finit */
if (tsk->thread_info->status & TS_USEDFPU) {
err = save_i387_checking((struct i387_fxsave_struct __user *)buf);
if (err) return err;
@@ -133,7 +134,7 @@ int dump_fpu( struct pt_regs *regs, stru
{
struct task_struct *tsk = current;

- if (!tsk->used_math)
+ if (!used_math())
return 0;

unlazy_fpu(tsk);
@@ -143,7 +144,7 @@ int dump_fpu( struct pt_regs *regs, stru

int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
{
- int fpvalid = tsk->used_math;
+ int fpvalid = !!tsk_used_math(tsk);

if (fpvalid) {
if (tsk == current)
--- mainline-5/arch/x86_64/kernel/process.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/x86_64/kernel/process.c 2005-01-21 06:20:02.290841408 +0100
@@ -314,7 +314,7 @@ void flush_thread(void)
* Forget coprocessor state..
*/
clear_fpu(tsk);
- tsk->used_math = 0;
+ clear_used_math();
}

void release_thread(struct task_struct *dead_task)
--- mainline-5/arch/x86_64/kernel/ptrace.c.orig 2005-01-04 01:13:11.000000000 +0100
+++ mainline-5/arch/x86_64/kernel/ptrace.c 2005-01-21 06:20:02.302839584 +0100
@@ -480,7 +480,7 @@ asmlinkage long sys_ptrace(long request,
ret = -EIO;
break;
}
- child->used_math = 1;
+ set_stopped_child_used_math(child);
ret = set_fpregs(child, (struct user_i387_struct __user *)data);
break;
}
--- mainline-5/arch/x86_64/kernel/signal.c.orig 2005-01-20 18:20:09.000000000 +0100
+++ mainline-5/arch/x86_64/kernel/signal.c 2005-01-21 06:20:02.304839280 +0100
@@ -251,7 +251,7 @@ static void setup_rt_frame(int sig, stru
int err = 0;
struct task_struct *me = current;

- if (me->used_math) {
+ if (used_math()) {
fp = get_stack(ka, regs, sizeof(struct _fpstate));
frame = (void __user *)round_down((unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;

--- mainline-5/arch/x86_64/kernel/traps.c.orig 2005-01-15 20:44:50.000000000 +0100
+++ mainline-5/arch/x86_64/kernel/traps.c 2005-01-21 06:20:02.318837152 +0100
@@ -901,7 +901,7 @@ asmlinkage void math_state_restore(void)
struct task_struct *me = current;
clts(); /* Allow maths ops (or we recurse) */

- if (!me->used_math)
+ if (!used_math())
init_fpu(me);
restore_fpu_checking(&me->thread.i387.fxsave);
me->thread_info->status |= TS_USEDFPU;
--- mainline-5/arch/m32r/kernel/ptrace.c.orig 2005-01-15 20:44:49.000000000 +0100
+++ mainline-5/arch/m32r/kernel/ptrace.c 2005-01-21 06:20:02.325836088 +0100
@@ -130,7 +130,7 @@ static int ptrace_read_user(struct task_
#ifndef NO_FPU
else if (off >= (long)(&dummy->fpu >> 2) &&
off < (long)(&dummy->u_fpvalid >> 2)) {
- if (!tsk->used_math) {
+ if (!tsk_used_math(tsk)) {
if (off == (long)(&dummy->fpu.fpscr >> 2))
tmp = FPSCR_INIT;
else
@@ -139,7 +139,7 @@ static int ptrace_read_user(struct task_
tmp = ((long *)(&tsk->thread.fpu >> 2))
[off - (long)&dummy->fpu];
} else if (off == (long)(&dummy->u_fpvalid >> 2))
- tmp = tsk->used_math;
+ tmp = !!tsk_used_math(tsk);
#endif /* not NO_FPU */
else
tmp = 0;
@@ -187,12 +187,12 @@ static int ptrace_write_user(struct task
#ifndef NO_FPU
else if (off >= (long)(&dummy->fpu >> 2) &&
off < (long)(&dummy->u_fpvalid >> 2)) {
- tsk->used_math = 1;
+ set_stopped_child_used_math(tsk);
((long *)&tsk->thread.fpu)
[off - (long)&dummy->fpu] = data;
ret = 0;
} else if (off == (long)(&dummy->u_fpvalid >> 2)) {
- tsk->used_math = data ? 1 : 0;
+ conditional_stopped_child_used_math(data, tsk);
ret = 0;
}
#endif /* not NO_FPU */
--- mainline-5/arch/m32r/kernel/setup.c.orig 2005-01-15 20:44:49.000000000 +0100
+++ mainline-5/arch/m32r/kernel/setup.c 2005-01-21 06:20:02.327835784 +0100
@@ -391,7 +391,7 @@ void __init cpu_init (void)

/* Force FPU initialization */
current_thread_info()->status = 0;
- current->used_math = 0;
+ clear_used_math();

#ifdef CONFIG_MMU
/* Set up MMU */
--- mainline-5/include/asm-arm26/constants.h.orig 2003-06-08 18:21:42.000000000 +0200
+++ mainline-5/include/asm-arm26/constants.h 2005-01-21 06:20:02.339833960 +0100
@@ -7,7 +7,6 @@
*
*/

-#define TSK_USED_MATH 788 /* offsetof(struct task_struct, used_math) */
#define TSK_ACTIVE_MM 96 /* offsetof(struct task_struct, active_mm) */

#define VMA_VM_MM 0 /* offsetof(struct vm_area_struct, vm_mm) */
--- mainline-5/include/asm-x86_64/i387.h.orig 2004-12-04 08:55:04.000000000 +0100
+++ mainline-5/include/asm-x86_64/i387.h 2005-01-21 06:20:02.349832440 +0100
@@ -25,16 +25,6 @@ extern void mxcsr_feature_mask_init(void
extern void init_fpu(struct task_struct *child);
extern int save_i387(struct _fpstate __user *buf);

-static inline int need_signal_i387(struct task_struct *me)
-{
- if (!me->used_math)
- return 0;
- me->used_math = 0;
- if (me->thread_info->status & TS_USEDFPU)
- return 0;
- return 1;
-}
-
/*
* FPU lazy state save handling...
*/
--- mainline-5/include/linux/sched.h.orig 2005-01-21 06:17:24.967758152 +0100
+++ mainline-5/include/linux/sched.h 2005-01-21 06:21:42.854553400 +0100
@@ -614,19 +614,7 @@ struct task_struct {
struct key *process_keyring; /* keyring private to this process (CLONE_THREAD) */
struct key *thread_keyring; /* keyring private to this thread */
#endif
-/*
- * Must be changed atomically so it shouldn't be
- * be a shareable bitflag.
- */
- unsigned char used_math;
-/*
- * OOM kill score adjustment (bit shift).
- * Cannot live together with used_math since
- * used_math and oomkilladj can be changed at the
- * same time, so they would race if they're in the
- * same atomic block.
- */
- short oomkilladj;
+ int oomkilladj; /* OOM kill score adjustment (bit shift). */
char comm[TASK_COMM_LEN];
/* file system info */
int link_count, total_link_count;
@@ -695,7 +683,7 @@ struct task_struct {
#endif
#ifdef CONFIG_NUMA
struct mempolicy *mempolicy;
- short il_next; /* could be shared with used_math */
+ short il_next;
#endif
};

@@ -737,7 +725,7 @@ do { if (atomic_dec_and_test(&(tsk)->usa
#define PF_SIGNALED 0x00000400 /* killed by a signal */
#define PF_MEMALLOC 0x00000800 /* Allocating memory */
#define PF_FLUSHER 0x00001000 /* responsible for disk writeback */
-
+#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
#define PF_FREEZE 0x00004000 /* this task is being frozen for suspend now */
#define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
#define PF_FROZEN 0x00010000 /* frozen for system suspend */
@@ -748,6 +736,31 @@ do { if (atomic_dec_and_test(&(tsk)->usa
#define PF_SYNCWRITE 0x00200000 /* I am doing a sync write */
#define PF_BORROWED_MM 0x00400000 /* I am a kthread doing use_mm */

+/*
+ * Only the _current_ task can read/write to tsk->flags, but other
+ * tasks can access tsk->flags in readonly mode for example
+ * with tsk_used_math (like during threaded core dumping).
+ * There is however an exception to this rule during ptrace
+ * or during fork: the ptracer task is allowed to write to the
+ * child->flags of its traced child (same goes for fork, the parent
+ * can write to the child->flags), because we're guaranteed the
+ * child is not running and in turn not changing child->flags
+ * at the same time the parent does it.
+ */
+#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
+#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
+#define clear_used_math() clear_stopped_child_used_math(current)
+#define set_used_math() set_stopped_child_used_math(current)
+#define conditional_stopped_child_used_math(condition, child) \
+ do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
+#define conditional_used_math(condition) \
+ conditional_stopped_child_used_math(condition, current)
+#define copy_to_stopped_child_used_math(child) \
+ do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
+/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
+#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
+#define used_math() tsk_used_math(current)
+
#ifdef CONFIG_SMP
extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
#else
--- mainline-oom/arch/i386/kernel/signal.c.~1~ 2005-01-15 20:44:49.000000000 +0100
+++ mainline-oom/arch/i386/kernel/signal.c 2005-01-21 06:27:20.433233640 +0100
@@ -192,9 +192,9 @@ restore_sigcontext(struct pt_regs *regs,
err |= restore_i387(buf);
} else {
struct task_struct *me = current;
- if (me->used_math) {
+ if (used_math()) {
clear_fpu(me);
- me->used_math = 0;
+ clear_used_math();
}
}
}
--- mainline-oom/arch/x86_64/ia32/ia32_signal.c.~1~ 2005-01-21 06:24:51.970803360 +0100
+++ mainline-oom/arch/x86_64/ia32/ia32_signal.c 2005-01-21 06:29:47.208920344 +0100
@@ -263,9 +263,9 @@ ia32_restore_sigcontext(struct pt_regs *
err |= restore_i387_ia32(current, buf, 0);
} else {
struct task_struct *me = current;
- if (me->used_math) {
+ if (used_math()) {
clear_fpu(me);
- me->used_math = 0;
+ clear_used_math();
}
}
}
--- mainline-oom/arch/x86_64/kernel/signal.c.~1~ 2005-01-21 06:24:51.975802600 +0100
+++ mainline-oom/arch/x86_64/kernel/signal.c 2005-01-21 06:29:41.988713936 +0100
@@ -126,9 +126,9 @@ restore_sigcontext(struct pt_regs *regs,
err |= restore_i387(buf);
} else {
struct task_struct *me = current;
- if (me->used_math) {
+ if (used_math()) {
clear_fpu(me);
- me->used_math = 0;
+ clear_used_math();
}
}
}
-
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