From db7d9a4eb700be766cc9f29241483dbb1e748832 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 24 Jul 2005 19:36:26 -0700 Subject: [SPARC64]: Move syscall success and newchild state out of thread flags. These two bits were accesses non-atomically from assembler code. So, in order to eliminate any potential races resulting from that, move these pieces of state into two bytes elsewhere in struct thread_info. Signed-off-by: David S. Miller --- arch/sparc64/kernel/entry.S | 17 ++++++++--------- arch/sparc64/kernel/process.c | 2 +- arch/sparc64/kernel/smp.c | 2 +- arch/sparc64/kernel/traps.c | 2 ++ 4 files changed, 12 insertions(+), 11 deletions(-) (limited to 'arch/sparc64') diff --git a/arch/sparc64/kernel/entry.S b/arch/sparc64/kernel/entry.S index d781f10..88332f0 100644 --- a/arch/sparc64/kernel/entry.S +++ b/arch/sparc64/kernel/entry.S @@ -1600,11 +1600,11 @@ sys_clone: flushw ba,pt %xcc, sparc_do_fork add %sp, PTREGS_OFF, %o2 ret_from_syscall: - /* Clear SPARC_FLAG_NEWCHILD, switch_to leaves thread.flags in - * %o7 for us. Check performance counter stuff too. + /* Clear current_thread_info()->new_child, and + * check performance counter stuff too. */ - andn %o7, _TIF_NEWCHILD, %l0 - stx %l0, [%g6 + TI_FLAGS] + stb %g0, [%g6 + TI_NEW_CHILD] + ldx [%g6 + TI_FLAGS], %l0 call schedule_tail mov %g7, %o0 andcc %l0, _TIF_PERFCTR, %g0 @@ -1720,12 +1720,11 @@ ret_sys_call: /* Check if force_successful_syscall_return() * was invoked. */ - ldx [%curptr + TI_FLAGS], %l0 - andcc %l0, _TIF_SYSCALL_SUCCESS, %g0 - be,pt %icc, 1f - andn %l0, _TIF_SYSCALL_SUCCESS, %l0 + ldub [%curptr + TI_SYS_NOERROR], %l0 + brz,pt %l0, 1f + nop ba,pt %xcc, 80f - stx %l0, [%curptr + TI_FLAGS] + stb %g0, [%curptr + TI_SYS_NOERROR] 1: cmp %o0, -ERESTART_RESTARTBLOCK diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c index a0cd2b2..cffb1c8 100644 --- a/arch/sparc64/kernel/process.c +++ b/arch/sparc64/kernel/process.c @@ -621,8 +621,8 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ)); t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) | - _TIF_NEWCHILD | (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT); + t->new_child = 1; t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS; t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf)); t->fpsaved[0] = 0; diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c index 7e8e291..b9b4249 100644 --- a/arch/sparc64/kernel/smp.c +++ b/arch/sparc64/kernel/smp.c @@ -137,7 +137,7 @@ void __init smp_callin(void) /* Clear this or we will die instantly when we * schedule back to this idler... */ - clear_thread_flag(TIF_NEWCHILD); + current_thread_info()->new_child = 0; /* Attach to the address space of init_task. */ atomic_inc(&init_mm.mm_count); diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c index a9f4596..100b010 100644 --- a/arch/sparc64/kernel/traps.c +++ b/arch/sparc64/kernel/traps.c @@ -2125,6 +2125,8 @@ void __init trap_init(void) TI_PCR != offsetof(struct thread_info, pcr_reg) || TI_CEE_STUFF != offsetof(struct thread_info, cee_stuff) || TI_PRE_COUNT != offsetof(struct thread_info, preempt_count) || + TI_NEW_CHILD != offsetof(struct thread_info, new_child) || + TI_SYS_NOERROR != offsetof(struct thread_info, syscall_noerror) || TI_FPREGS != offsetof(struct thread_info, fpregs) || (TI_FPREGS & (64 - 1))) thread_info_offsets_are_bolixed_dave(); -- cgit v1.1