diff options
| -rw-r--r-- | arch/ia64/kernel/process.c | 6 | ||||
| -rw-r--r-- | arch/ia64/kernel/ptrace.c | 82 | ||||
| -rw-r--r-- | include/asm-ia64/ptrace.h | 7 | ||||
| -rw-r--r-- | include/asm-ia64/thread_info.h | 2 |
4 files changed, 97 insertions, 0 deletions
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 5c9efe6..be6c6f7 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -163,6 +163,8 @@ void tsk_clear_notify_resume(struct task_struct *tsk) 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); } @@ -184,6 +186,10 @@ do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall /* 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(); } static int pal_halt = 1; diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 2e96f17..2de5a52 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -547,6 +547,72 @@ ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw, return 0; } +static 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; +} + +typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *, + unsigned long, unsigned long); + +static void do_sync_rbs(struct unw_frame_info *info, void *arg) +{ + struct pt_regs *pt; + unsigned long urbs_end; + syncfunc_t fn = arg; + + if (unw_unwind_to_user(info) < 0) + return; + pt = task_pt_regs(info->task); + urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL); + + fn(info->task, info->sw, pt->ar_bspstore, urbs_end); +} + +/* + * when a thread is stopped (ptraced), debugger might change thread's user + * stack (change memory directly), and we must avoid the RSE stored in kernel + * to override user stack (user space's RSE is newer than kernel's in the + * case). To workaround the issue, we copy kernel RSE to user RSE before the + * task is stopped, so user RSE has updated data. we then copy user RSE to + * kernel after the task is resummed from traced stop and kernel will use the + * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need + * synchronize user RSE to kernel. + */ +void ia64_ptrace_stop(void) +{ + if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE)) + return; + tsk_set_notify_resume(current); + unw_init_running(do_sync_rbs, ia64_sync_user_rbs); +} + +/* + * This is called to read back the register backing store. + */ +void ia64_sync_krbs(void) +{ + clear_tsk_thread_flag(current, TIF_RESTORE_RSE); + tsk_clear_notify_resume(current); + + unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs); +} + static inline int thread_matches (struct task_struct *thread, unsigned long addr) { @@ -1422,6 +1488,7 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) struct task_struct *child; struct switch_stack *sw; long ret; + struct unw_frame_info info; lock_kernel(); ret = -EPERM; @@ -1453,6 +1520,8 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) if (request == PTRACE_ATTACH) { ret = ptrace_attach(child); + if (!ret) + arch_ptrace_attach(child); goto out_tsk; } @@ -1481,6 +1550,11 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) /* write the word at location addr */ urbs_end = ia64_get_user_rbs_end(child, pt, NULL); ret = ia64_poke(child, sw, urbs_end, addr, data); + + /* Make sure user RBS has the latest data */ + unw_init_from_blocked_task(&info, child); + do_sync_rbs(&info, ia64_sync_user_rbs); + goto out_tsk; case PTRACE_PEEKUSR: @@ -1634,6 +1708,10 @@ syscall_trace_enter (long arg0, long arg1, long arg2, long arg3, && (current->ptrace & PT_PTRACED)) syscall_trace(); + /* copy user rbs to kernel rbs */ + if (test_thread_flag(TIF_RESTORE_RSE)) + ia64_sync_krbs(); + if (unlikely(current->audit_context)) { long syscall; int arch; @@ -1671,4 +1749,8 @@ syscall_trace_leave (long arg0, long arg1, long arg2, long arg3, || test_thread_flag(TIF_SINGLESTEP)) && (current->ptrace & PT_PTRACED)) syscall_trace(); + + /* copy user rbs to kernel rbs */ + if (test_thread_flag(TIF_RESTORE_RSE)) + ia64_sync_krbs(); } diff --git a/include/asm-ia64/ptrace.h b/include/asm-ia64/ptrace.h index f4ef87a..13435f7 100644 --- a/include/asm-ia64/ptrace.h +++ b/include/asm-ia64/ptrace.h @@ -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 void ia64_sync_krbs(void); extern long ia64_sync_user_rbs (struct task_struct *, struct switch_stack *, unsigned long, unsigned long); @@ -303,6 +304,12 @@ struct switch_stack { extern void ia64_increment_ip (struct pt_regs *pt); extern void ia64_decrement_ip (struct pt_regs *pt); + extern void ia64_ptrace_stop(void); + #define arch_ptrace_stop(code, info) \ + ia64_ptrace_stop() + #define arch_ptrace_stop_needed(code, info) \ + (!test_thread_flag(TIF_RESTORE_RSE)) + #endif /* !__KERNEL__ */ /* pt_all_user_regs is used for PTRACE_GETREGS PTRACE_SETREGS */ diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h index 5a2c479..93d83cb 100644 --- a/include/asm-ia64/thread_info.h +++ b/include/asm-ia64/thread_info.h @@ -94,6 +94,7 @@ extern void tsk_clear_notify_resume(struct task_struct *tsk); #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 /* user RBS is newer than kernel RBS */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) @@ -107,6 +108,7 @@ extern void tsk_clear_notify_resume(struct task_struct *tsk); #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_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\ |
