Merge branch 'master' of ssh://master.kernel.org/pub/scm/linux/kernel/git/torvalds...

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 2bf27f364d098c210ed7cca9ece5edca613a9f2b..8182f45ca493724f732f59cfe38e69a7c45afe44 100644 (file)
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -767,12 +767,20 @@ long arch_ptrace(struct task_struct *child, long request,
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
                case PTRACE_GETHBPREGS:
+                       if (ptrace_get_breakpoints(child) < 0)
+                               return -ESRCH;
+
                        ret = ptrace_gethbpregs(child, addr,
                                                (unsigned long __user *)data);
+                       ptrace_put_breakpoints(child);
                        break;
                case PTRACE_SETHBPREGS:
+                       if (ptrace_get_breakpoints(child) < 0)
+                               return -ESRCH;
+
                        ret = ptrace_sethbpregs(child, addr,
                                                (unsigned long __user *)data);
+                       ptrace_put_breakpoints(child);
                        break;
 #endif
 

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 55613e33e263ac7abb3b1d478f4a27bb9912b86f..4edeeb325429dd6b8e10c44ccf51057659ea5d5b 100644 (file)
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1591,7 +1591,10 @@ long arch_ptrace(struct task_struct *child, long request,
        }
 
        case PTRACE_SET_DEBUGREG:
+               if (ptrace_get_breakpoints(child) < 0)
+                       return -ESRCH;
                ret = ptrace_set_debugreg(child, addr, data);
+               ptrace_put_breakpoints(child);
                break;
 
 #ifdef CONFIG_PPC64

diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index 2130ca674e9bdd1674a22d339011a7f364bf0ec5..3d7b209b2178cc63c520975a35d4146c99042ba4 100644 (file)
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -117,7 +117,11 @@ void user_enable_single_step(struct task_struct *child)
 
        set_tsk_thread_flag(child, TIF_SINGLESTEP);
 
+       if (ptrace_get_breakpoints(child) < 0)
+               return;
+
        set_single_step(child, pc);
+       ptrace_put_breakpoints(child);
 }
 
 void user_disable_single_step(struct task_struct *child)

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 45892dc4b72a37f01627725db2654591fc4dad6b..f65e5b521dbd4b3d28c8dc30faecec02073e56fb 100644 (file)
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -608,6 +608,9 @@ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
        unsigned len, type;
        struct perf_event *bp;
 
+       if (ptrace_get_breakpoints(tsk) < 0)
+               return -ESRCH;
+
        data &= ~DR_CONTROL_RESERVED;
        old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 restore:
@@ -655,6 +658,9 @@ restore:
                }
                goto restore;
        }
+
+       ptrace_put_breakpoints(tsk);
+
        return ((orig_ret < 0) ? orig_ret : rc);
 }
 
@@ -668,10 +674,17 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 
        if (n < HBP_NUM) {
                struct perf_event *bp;
+
+               if (ptrace_get_breakpoints(tsk) < 0)
+                       return -ESRCH;
+
                bp = thread->ptrace_bps[n];
                if (!bp)
-                       return 0;
-               val = bp->hw.info.address;
+                       val = 0;
+               else
+                       val = bp->hw.info.address;
+
+               ptrace_put_breakpoints(tsk);
        } else if (n == 6) {
                val = thread->debugreg6;
         } else if (n == 7) {
@@ -686,6 +699,10 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
        struct perf_event *bp;
        struct thread_struct *t = &tsk->thread;
        struct perf_event_attr attr;
+       int err = 0;
+
+       if (ptrace_get_breakpoints(tsk) < 0)
+               return -ESRCH;
 
        if (!t->ptrace_bps[nr]) {
                ptrace_breakpoint_init(&attr);
@@ -709,24 +726,23 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
                 * writing for the user. And anyway this is the previous
                 * behaviour.
                 */
-               if (IS_ERR(bp))
-                       return PTR_ERR(bp);
+               if (IS_ERR(bp)) {
+                       err = PTR_ERR(bp);
+                       goto put;
+               }
 
                t->ptrace_bps[nr] = bp;
        } else {
-               int err;
-
                bp = t->ptrace_bps[nr];
 
                attr = bp->attr;
                attr.bp_addr = addr;
                err = modify_user_hw_breakpoint(bp, &attr);
-               if (err)
-                       return err;
        }
 
-
-       return 0;
+put:
+       ptrace_put_breakpoints(tsk);
+       return err;
 }
 
 /*

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index a1147e5dd245e8d7d262598b3c920ceb796efd00..9178d5cc0b0143a0e81336e6dea09e1cbedab86e 100644 (file)
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -189,6 +189,10 @@ static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
                child->ptrace = current->ptrace;
                __ptrace_link(child, current->parent);
        }
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+       atomic_set(&child->ptrace_bp_refcnt, 1);
+#endif
 }
 
 /**
@@ -350,6 +354,13 @@ extern int task_current_syscall(struct task_struct *target, long *callno,
                                unsigned long args[6], unsigned int maxargs,
                                unsigned long *sp, unsigned long *pc);
 
-#endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+extern int ptrace_get_breakpoints(struct task_struct *tsk);
+extern void ptrace_put_breakpoints(struct task_struct *tsk);
+#else
+static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+
+#endif /* __KERNEL */
 
 #endif

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 18d63cea28481c478906f791e384b520ad1f483b..781abd13767302cce2ba08db01a211e3178de0d9 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1537,6 +1537,9 @@ struct task_struct {
                unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
        } memcg_batch;
 #endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+       atomic_t ptrace_bp_refcnt;
+#endif
 };
 
 /* Future-safe accessor for struct task_struct's cpus_allowed. */

diff --git a/kernel/exit.c b/kernel/exit.c
index f5d2f63bae0b70b2818edd92e06040906f115216..8dd87418154205940341f98641191fe1c1d6ea70 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1016,7 +1016,7 @@ NORET_TYPE void do_exit(long code)
        /*
         * FIXME: do that only when needed, using sched_exit tracepoint
         */
-       flush_ptrace_hw_breakpoint(tsk);
+       ptrace_put_breakpoints(tsk);
 
        exit_notify(tsk, group_dead);
 #ifdef CONFIG_NUMA

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 0fc1eed28d2783e0b2779fe50d1ff86fbf4ca858..dc7ab65f3b36cb0b71c8365e13d0e73a9601f6ee 100644 (file)
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -22,6 +22,7 @@
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
 #include <linux/regset.h>
+#include <linux/hw_breakpoint.h>
 
 
 /*
@@ -879,3 +880,19 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
        return ret;
 }
 #endif /* CONFIG_COMPAT */
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+int ptrace_get_breakpoints(struct task_struct *tsk)
+{
+       if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
+               return 0;
+
+       return -1;
+}
+
+void ptrace_put_breakpoints(struct task_struct *tsk)
+{
+       if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
+               flush_ptrace_hw_breakpoint(tsk);
+}
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */