[PATCH] Fix sparc TIF_USEDFPU flag atomicity

[Mathieu Desnoyers]

Fix sparc TIF_USEDFPU flag atomicity

Non atomic update of TIF can be very dangerous, except at thread structure
creation time. Here I standardize the TIF_USEDFPU usage of the sparc arch.

Applies on 2.6.20.

Signed-off-by: Mathieu Desnoyers <[EMAIL PROTECTED]>

--- a/arch/sparc/kernel/process.c
+++ b/arch/sparc/kernel/process.c
@@ -348,7 +348,7 @@ void exit_thread(void)
 #ifndef CONFIG_SMP
        if(last_task_used_math == current) {
 #else
-       if(current_thread_info()->flags & _TIF_USEDFPU) {
+       if(test_tsk_thread_flag(current, TIF_USEDFPU)) {
 #endif
                /* Keep process from leaving FPU in a bogon state. */
                put_psr(get_psr() | PSR_EF);
@@ -357,7 +357,7 @@ void exit_thread(void)
 #ifndef CONFIG_SMP
                last_task_used_math = NULL;
 #else
-               current_thread_info()->flags &= ~_TIF_USEDFPU;
+               clear_tsk_thread_flag(current, TIF_USEDFPU);
 #endif
        }
 }
@@ -371,7 +371,7 @@ void flush_thread(void)
 #ifndef CONFIG_SMP
        if(last_task_used_math == current) {
 #else
-       if(current_thread_info()->flags & _TIF_USEDFPU) {
+       if(test_tsk_thread_flag(current, TIF_USEDFPU)) {
 #endif
                /* Clean the fpu. */
                put_psr(get_psr() | PSR_EF);
@@ -380,7 +380,7 @@ void flush_thread(void)
 #ifndef CONFIG_SMP
                last_task_used_math = NULL;
 #else
-               current_thread_info()->flags &= ~_TIF_USEDFPU;
+               clear_tsk_thread_flag(current, TIF_USEDFPU);
 #endif
        }
 
@@ -466,13 +466,13 @@ int copy_thread(int nr, unsigned long clone_flags, 
unsigned long sp,
 #ifndef CONFIG_SMP
        if(last_task_used_math == current) {
 #else
-       if(current_thread_info()->flags & _TIF_USEDFPU) {
+       if(test_tsk_thread_flag(current, TIF_USEDFPU)) {
 #endif
                put_psr(get_psr() | PSR_EF);
                fpsave(&p->thread.float_regs[0], &p->thread.fsr,
                       &p->thread.fpqueue[0], &p->thread.fpqdepth);
 #ifdef CONFIG_SMP
-               current_thread_info()->flags &= ~_TIF_USEDFPU;
+               clear_tsk_thread_flag(current, TIF_USEDFPU);
 #endif
        }
 
@@ -609,13 +609,13 @@ int dump_fpu (struct pt_regs * regs, elf_fpregset_t * 
fpregs)
                return 1;
        }
 #ifdef CONFIG_SMP
-       if (current_thread_info()->flags & _TIF_USEDFPU) {
+       if (test_tsk_thread_flag(current, TIF_USEDFPU)) {
                put_psr(get_psr() | PSR_EF);
                fpsave(&current->thread.float_regs[0], &current->thread.fsr,
                       &current->thread.fpqueue[0], &current->thread.fpqdepth);
                if (regs != NULL) {
                        regs->psr &= ~(PSR_EF);
-                       current_thread_info()->flags &= ~(_TIF_USEDFPU);
+                       clear_tsk_thread_flag(current, TIF_USEDFPU);
                }
        }
 #else
diff --git a/arch/sparc/kernel/traps.c b/arch/sparc/kernel/traps.c
index 6a70d21..7a7ad05 100644
--- a/arch/sparc/kernel/traps.c
+++ b/arch/sparc/kernel/traps.c
@@ -259,7 +259,7 @@ void do_fpd_trap(struct pt_regs *regs, unsigned long pc, 
unsigned long npc,
        } else {
                fpload(&current->thread.float_regs[0], &current->thread.fsr);
        }
-       current_thread_info()->flags |= _TIF_USEDFPU;
+       set_tsk_thread_flag(current, TIF_USEDFPU);
 #endif
 }
 
@@ -290,7 +290,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, 
unsigned long npc,
 #ifndef CONFIG_SMP
        if(!fpt) {
 #else
-        if(!(task_thread_info(fpt)->flags & _TIF_USEDFPU)) {
+        if(!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 #endif
                fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
                regs->psr &= ~PSR_EF;
@@ -333,7 +333,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, 
unsigned long npc,
        /* nope, better SIGFPE the offending process... */
               
 #ifdef CONFIG_SMP
-       task_thread_info(fpt)->flags &= ~_TIF_USEDFPU;
+       clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 #endif
        if(psr & PSR_PS) {
                /* The first fsr store/load we tried trapped,
-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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