Hi, Well, looks like we need to resurect TIF_NOTIFY_RESUME now that we do have some actual need for it. This implies that I need to rework my perfmon new code base to take this into account. I don't want to use pfm_needs_checking. So maybe it is okay to use a higher order TIF bit for perfmon on IA-64 combined with TIF_NOTIFY_RESUME. For the RSE part, I am not sure I understand the logic behind this change. I think more explanantions maybe needed to calrify this a bit more. On Wed, Aug 08, 2007 at 10:30:37AM +0800, Shaohua Li wrote: > On Tue, 2007-08-07 at 15:13 +0800, Roland McGrath wrote: > > That looks reasonable to me, not being expert on the ia64 details. > > I rolled that into utrace-regset-ia64.patch in the 2.6.22 backport > > version. > > > > > patch is against latest utrace source (2.6.22 base + utrace patches) > > > > The latest utrace source is based on 2.6.23-rc2, and your patch does > > not > > apply there. TIF_NOTIFY_RESUME has been renamed to TIF_PERFMON_WORK. > > So you need to rename it back (or to something else) to overload it. > > > > If the gist of your patch here seems right to ia64 folks, then I'd > > suggest > > you do a patch adding ia64_sync_krbs to the upstream kernel. That > > would be > > the necessary prelude to doing the arch_ptrace_stop plan, which I can > > help > > ia64 folks with later. > Ok, this is the patch against 2.6.23-rc2 > > > In ptrace case, user space RSE might be newer than kernel RSE. To avoid > stale RSE is used when return to userspace, this patch synchronize user > space RSE to kernel RSE. > Also, as TIF_ALLWORK_MASK bits are limited, TIF_NOTIFY_RESUME is > overrided. > > Signed-off-by: Bibo Mao<bibo.mao@xxxxxxxxx> > Signed-off-by: Shaohua Li<shaohua.li@xxxxxxxxx> > > ============================================================== > arch/ia64/kernel/perfmon.c | 21 ++-------------- > arch/ia64/kernel/process.c | 14 +++++++++++ > arch/ia64/kernel/ptrace.c | 52 +++++++++++++++++++++++++++++++++++++++++ > include/asm-ia64/ptrace.h | 1 > include/asm-ia64/thread_info.h | 11 ++++++-- > 5 files changed, 78 insertions(+), 21 deletions(-) > > Index: 2.6.23-rc2/arch/ia64/kernel/process.c > =================================================================== > --- 2.6.23-rc2.orig/arch/ia64/kernel/process.c 2007-08-04 10:49:55.000000000 +0800 > +++ 2.6.23-rc2/arch/ia64/kernel/process.c 2007-08-08 09:27:18.000000000 +0800 > @@ -154,6 +154,17 @@ show_regs (struct pt_regs *regs) > show_stack(NULL, NULL); > } > > +void tsk_clear_notify_resume(struct task_struct *tsk) > +{ > +#ifdef CONFIG_PERFMON > + if (tsk->thread.pfm_needs_checking) > + return; > +#endif > + if (test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_RSE)) > + return; > + clear_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME); > +} > + > void > do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall) > { > @@ -172,6 +183,9 @@ do_notify_resume_user (sigset_t *unused, > /* deal with pending signal delivery */ > if (test_thread_flag(TIF_SIGPENDING)||test_thread_flag(TIF_RESTORE_SIGMASK)) > ia64_do_signal(scr, in_syscall); > + /* copy user rbs to kernel rbs */ > + if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) > + ia64_sync_krbs(current); > } > > static int pal_halt = 1; > Index: 2.6.23-rc2/arch/ia64/kernel/ptrace.c > =================================================================== > --- 2.6.23-rc2.orig/arch/ia64/kernel/ptrace.c 2007-08-08 09:00:28.000000000 +0800 > +++ 2.6.23-rc2/arch/ia64/kernel/ptrace.c 2007-08-08 09:27:18.000000000 +0800 > @@ -554,6 +554,25 @@ ia64_sync_user_rbs (struct task_struct * > return 0; > } > > +long > +ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw, > + unsigned long user_rbs_start, unsigned long user_rbs_end) > +{ > + unsigned long addr, val; > + long ret; > + > + /* now copy word for word from user rbs to kernel rbs: */ > + for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) { > + if (access_process_vm(child, addr, &val, sizeof(val), 0) > + != sizeof(val)) > + return -EIO; > + ret = ia64_poke(child, sw, user_rbs_end, addr, val); > + if (ret < 0) > + return ret; > + } > + return 0; > +} > + > /* > * Write f32-f127 back to task->thread.fph if it has been modified. > */ > @@ -728,6 +747,10 @@ syscall_trace_enter (long arg0, long arg > if (test_thread_flag(TIF_SYSCALL_TRACE)) > tracehook_report_syscall(®s, 0); > > + /* copy user rbs to kernel rbs */ > + if (test_thread_flag(TIF_RESTORE_RSE)) > + ia64_sync_krbs(current); > + > if (unlikely(current->audit_context)) { > long syscall; > int arch; > @@ -764,6 +787,10 @@ syscall_trace_leave (long arg0, long arg > if (test_thread_flag(TIF_SYSCALL_TRACE)) > tracehook_report_syscall(®s, 1); > > + /* copy user rbs to kernel rbs */ > + if (test_thread_flag(TIF_RESTORE_RSE)) > + ia64_sync_krbs(current); > + > if (test_thread_flag(TIF_SINGLESTEP)) { > force_sig(SIGTRAP, current); /* XXX */ > tracehook_report_syscall_step(®s); > @@ -1416,9 +1443,34 @@ gpregs_writeback(struct task_struct *tar > const struct utrace_regset *regset, > int now) > { > + if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE)) > + return 0; > + tsk_set_notify_resume(target); > return do_regset_call(do_gpregs_writeback, target, regset, 0, 0, NULL, NULL); > } > > +static void do_gpregs_readback(struct unw_frame_info *info, void *arg) > +{ > + struct pt_regs *pt; > + utrace_getset_t *dst = arg; > + unsigned long urbs_end; > + > + if (unw_unwind_to_user(info) < 0) > + return; > + pt = task_pt_regs(dst->target); > + urbs_end = ia64_get_user_rbs_end(dst->target, pt, NULL); > + dst->ret = ia64_sync_kernel_rbs(dst->target, info->sw, pt->ar_bspstore, urbs_end); > +} > +/* > + * This is called to read back the register backing store. > + */ > +long ia64_sync_krbs(struct task_struct *target) > +{ > + clear_tsk_thread_flag(target, TIF_RESTORE_RSE); > + tsk_clear_notify_resume(target); > + return do_regset_call(do_gpregs_readback, target, NULL, 0, 0, NULL, NULL); > +} > + > static int > fpregs_active(struct task_struct *target, const struct utrace_regset *regset) > { > Index: 2.6.23-rc2/include/asm-ia64/ptrace.h > =================================================================== > --- 2.6.23-rc2.orig/include/asm-ia64/ptrace.h 2007-08-04 10:49:55.000000000 +0800 > +++ 2.6.23-rc2/include/asm-ia64/ptrace.h 2007-08-08 09:27:18.000000000 +0800 > @@ -292,6 +292,7 @@ struct switch_stack { > unsigned long, long); > extern void ia64_flush_fph (struct task_struct *); > extern void ia64_sync_fph (struct task_struct *); > + extern long ia64_sync_krbs(struct task_struct *); > extern long ia64_sync_user_rbs (struct task_struct *, struct switch_stack *, > unsigned long, unsigned long); > > Index: 2.6.23-rc2/include/asm-ia64/thread_info.h > =================================================================== > --- 2.6.23-rc2.orig/include/asm-ia64/thread_info.h 2007-08-04 10:49:55.000000000 +0800 > +++ 2.6.23-rc2/include/asm-ia64/thread_info.h 2007-08-08 09:35:08.000000000 +0800 > @@ -71,6 +71,9 @@ struct thread_info { > #define alloc_task_struct() ((struct task_struct *)__get_free_pages(GFP_KERNEL | __GFP_COMP, KERNEL_STACK_SIZE_ORDER)) > #define free_task_struct(tsk) free_pages((unsigned long) (tsk), KERNEL_STACK_SIZE_ORDER) > > +#define tsk_set_notify_resume(tsk) \ > + set_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME) > +extern void tsk_clear_notify_resume(struct task_struct *tsk); > #endif /* !__ASSEMBLY */ > > /* > @@ -85,28 +88,30 @@ struct thread_info { > #define TIF_SYSCALL_AUDIT 3 /* syscall auditing active */ > #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ > #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */ > -#define TIF_PERFMON_WORK 6 /* work for pfm_handle_work() */ > +#define TIF_NOTIFY_RESUME 6 /* resumption notification requested */ > #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ > #define TIF_MEMDIE 17 > #define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */ > #define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */ > #define TIF_FREEZE 20 /* is freezing for suspend */ > +#define TIF_RESTORE_RSE 21 /* task need RSE synchronization */ > > #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) > #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) > #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) > #define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP) > #define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK) > -#define _TIF_PERFMON_WORK (1 << TIF_PERFMON_WORK) > +#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) > #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) > #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) > #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) > #define _TIF_MCA_INIT (1 << TIF_MCA_INIT) > #define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED) > #define _TIF_FREEZE (1 << TIF_FREEZE) > +#define _TIF_RESTORE_RSE (1 << TIF_RESTORE_RSE) > > /* "work to do on user-return" bits */ > -#define TIF_ALLWORK_MASK (_TIF_SIGPENDING|_TIF_PERFMON_WORK|_TIF_SYSCALL_AUDIT|\ > +#define TIF_ALLWORK_MASK (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\ > _TIF_NEED_RESCHED| _TIF_SYSCALL_TRACE|\ > _TIF_RESTORE_SIGMASK) > /* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */ > Index: 2.6.23-rc2/arch/ia64/kernel/perfmon.c > =================================================================== > --- 2.6.23-rc2.orig/arch/ia64/kernel/perfmon.c 2007-08-04 10:49:55.000000000 +0800 > +++ 2.6.23-rc2/arch/ia64/kernel/perfmon.c 2007-08-08 09:32:41.000000000 +0800 > @@ -586,21 +586,6 @@ pfm_put_task(struct task_struct *task) > } > > static inline void > -pfm_set_task_notify(struct task_struct *task) > -{ > - struct thread_info *info; > - > - info = (struct thread_info *) ((char *) task + IA64_TASK_SIZE); > - set_bit(TIF_PERFMON_WORK, &info->flags); > -} > - > -static inline void > -pfm_clear_task_notify(void) > -{ > - clear_thread_flag(TIF_PERFMON_WORK); > -} > - > -static inline void > pfm_reserve_page(unsigned long a) > { > SetPageReserved(vmalloc_to_page((void *)a)); > @@ -3730,7 +3715,7 @@ pfm_restart(pfm_context_t *ctx, void *ar > > PFM_SET_WORK_PENDING(task, 1); > > - pfm_set_task_notify(task); > + tsk_set_notify_resume(task); > > /* > * XXX: send reschedule if task runs on another CPU > @@ -5087,7 +5072,7 @@ pfm_handle_work(void) > > PFM_SET_WORK_PENDING(current, 0); > > - pfm_clear_task_notify(); > + tsk_clear_notify_resume(current); > > regs = task_pt_regs(current); > > @@ -5455,7 +5440,7 @@ pfm_overflow_handler(struct task_struct > * when coming from ctxsw, current still points to the > * previous task, therefore we must work with task and not current. > */ > - pfm_set_task_notify(task); > + tsk_set_notify_resume(task); > } > /* > * defer until state is changed (shorten spin window). the context is locked > - > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- -Stephane - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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