From 3185bd26188223195dc2e659a3d00219cad71a0f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 20 Oct 2012 15:52:23 +0100 Subject: alpha: separate thread-synchronous flags ... and fix the race in updating unaligned control ones Signed-off-by: Al Viro Signed-off-by: Linus Torvalds --- arch/alpha/include/asm/thread_info.h | 80 ++++++++++++++++++++++++------------ arch/alpha/kernel/osf_sys.c | 25 +++++------ arch/alpha/kernel/process.c | 2 +- arch/alpha/kernel/traps.c | 6 +-- 4 files changed, 68 insertions(+), 45 deletions(-) (limited to 'arch') diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h index 4554ecbff7c6..1f8c72959fb6 100644 --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -7,6 +7,7 @@ #include #include #include +#include #endif #ifndef __ASSEMBLY__ @@ -21,6 +22,7 @@ struct thread_info { mm_segment_t addr_limit; /* thread address space */ unsigned cpu; /* current CPU */ int preempt_count; /* 0 => preemptable, <0 => BUG */ + unsigned int status; /* thread-synchronous flags */ int bpt_nsaved; unsigned long bpt_addr[2]; /* breakpoint handling */ @@ -63,8 +65,6 @@ register struct thread_info *__current_thread_info __asm__("$8"); * - these are process state flags and used from assembly * - pending work-to-be-done flags come first and must be assigned to be * within bits 0 to 7 to fit in and immediate operand. - * - ALPHA_UAC_SHIFT below must be kept consistent with the unaligned - * control flags. * * TIF_SYSCALL_TRACE is known to be 0 via blbs. */ @@ -72,18 +72,12 @@ register struct thread_info *__current_thread_info __asm__("$8"); #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ -#define TIF_POLLING_NRFLAG 8 /* poll_idle is polling NEED_RESCHED */ #define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */ -#define TIF_UAC_NOPRINT 10 /* ! Preserve sequence of following */ -#define TIF_UAC_NOFIX 11 /* ! flags as they match */ -#define TIF_UAC_SIGBUS 12 /* ! userspace part of 'osf_sysinfo' */ #define TIF_MEMDIE 13 /* is terminating due to OOM killer */ -#define TIF_RESTORE_SIGMASK 14 /* restore signal mask in do_signal */ #define _TIF_SYSCALL_TRACE (1<flags = ((task_thread_info(task)->flags & \ - ~ALPHA_UAC_MASK) \ - | (((value) << ALPHA_UAC_SHIFT) & (1<status & TS_POLLING) + +#ifndef __ASSEMBLY__ +#define HAVE_SET_RESTORE_SIGMASK 1 +static inline void set_restore_sigmask(void) +{ + struct thread_info *ti = current_thread_info(); + ti->status |= TS_RESTORE_SIGMASK; + WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); +} +static inline void clear_restore_sigmask(void) +{ + current_thread_info()->status &= ~TS_RESTORE_SIGMASK; +} +static inline bool test_restore_sigmask(void) +{ + return current_thread_info()->status & TS_RESTORE_SIGMASK; +} +static inline bool test_and_clear_restore_sigmask(void) +{ + struct thread_info *ti = current_thread_info(); + if (!(ti->status & TS_RESTORE_SIGMASK)) + return false; + ti->status &= ~TS_RESTORE_SIGMASK; + return true; +} +#endif + +#define SET_UNALIGN_CTL(task,value) ({ \ + __u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \ + if (value & PR_UNALIGN_NOPRINT) \ + status |= TS_UAC_NOPRINT; \ + if (value & PR_UNALIGN_SIGBUS) \ + status |= TS_UAC_SIGBUS; \ + if (value & 4) /* alpha-specific */ \ + status |= TS_UAC_NOFIX; \ + task_thread_info(task)->status = status; \ 0; }) #define GET_UNALIGN_CTL(task,value) ({ \ - put_user((task_thread_info(task)->flags & (1 << TIF_UAC_NOPRINT))\ - >> ALPHA_UAC_SHIFT \ - | (task_thread_info(task)->flags & (1 << TIF_UAC_SIGBUS))\ - >> (ALPHA_UAC_SHIFT + 1) \ - | (task_thread_info(task)->flags & (1 << TIF_UAC_NOFIX))\ - >> (ALPHA_UAC_SHIFT - 1), \ - (int __user *)(value)); \ + __u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \ + __u32 res = 0; \ + if (status & TS_UAC_NOPRINT) \ + res |= PR_UNALIGN_NOPRINT; \ + if (status & TS_UAC_SIGBUS) \ + res |= PR_UNALIGN_SIGBUS; \ + if (status & TS_UAC_NOFIX) \ + res |= 4; \ + put_user(res, (int __user *)(value)); \ }) -#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) - #endif /* __KERNEL__ */ #endif /* _ALPHA_THREAD_INFO_H */ diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index 9eb090582cf1..1e6956a90608 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -793,8 +793,7 @@ SYSCALL_DEFINE5(osf_getsysinfo, unsigned long, op, void __user *, buffer, case GSI_UACPROC: if (nbytes < sizeof(unsigned int)) return -EINVAL; - w = (current_thread_info()->flags >> ALPHA_UAC_SHIFT) & - UAC_BITMASK; + w = current_thread_info()->status & UAC_BITMASK; if (put_user(w, (unsigned int __user *)buffer)) return -EFAULT; return 1; @@ -904,24 +903,20 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer, break; case SSI_NVPAIRS: { - unsigned long v, w, i; - unsigned int old, new; + unsigned __user *p = buffer; + unsigned i; - for (i = 0; i < nbytes; ++i) { + for (i = 0, p = buffer; i < nbytes; ++i, p += 2) { + unsigned v, w, status; - if (get_user(v, 2*i + (unsigned int __user *)buffer)) - return -EFAULT; - if (get_user(w, 2*i + 1 + (unsigned int __user *)buffer)) + if (get_user(v, p) || get_user(w, p + 1)) return -EFAULT; switch (v) { case SSIN_UACPROC: - again: - old = current_thread_info()->flags; - new = old & ~(UAC_BITMASK << ALPHA_UAC_SHIFT); - new = new | (w & UAC_BITMASK) << ALPHA_UAC_SHIFT; - if (cmpxchg(¤t_thread_info()->flags, - old, new) != old) - goto again; + w &= UAC_BITMASK; + status = current_thread_info()->status; + status = (status & ~UAC_BITMASK) | w; + current_thread_info()->status = status; break; default: diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 4054e0ffe2b2..51987dcf79b8 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -49,7 +49,7 @@ EXPORT_SYMBOL(pm_power_off); void cpu_idle(void) { - set_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status |= TS_POLLING; while (1) { /* FIXME -- EV6 and LCA45 know how to power down diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c index 80d987c0e9aa..272666d006df 100644 --- a/arch/alpha/kernel/traps.c +++ b/arch/alpha/kernel/traps.c @@ -780,17 +780,17 @@ do_entUnaUser(void __user * va, unsigned long opcode, /* Check the UAC bits to decide what the user wants us to do with the unaliged access. */ - if (!test_thread_flag (TIF_UAC_NOPRINT)) { + if (!(current_thread_info()->status & TS_UAC_NOPRINT)) { if (__ratelimit(&ratelimit)) { printk("%s(%d): unaligned trap at %016lx: %p %lx %ld\n", current->comm, task_pid_nr(current), regs->pc - 4, va, opcode, reg); } } - if (test_thread_flag (TIF_UAC_SIGBUS)) + if ((current_thread_info()->status & TS_UAC_SIGBUS)) goto give_sigbus; /* Not sure why you'd want to use this, but... */ - if (test_thread_flag (TIF_UAC_NOFIX)) + if ((current_thread_info()->status & TS_UAC_NOFIX)) return; /* Don't bother reading ds in the access check since we already -- cgit v1.2.3-70-g09d2