uprobes: Do not setup ->active_uprobe/state prematurely

handle_swbp() sets utask->active_uprobe before handler_chain(),
and UTASK_SSTEP before pre_ssout(). This complicates the code
for no reason,  arch_ hooks or consumer->handler() should not
(and can't) use this info.

Change handle_swbp() to initialize them after pre_ssout(), and
remove the no longer needed cleanup-utask code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
cked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2c1ff05af6f5..41f048c91425 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1496,22 +1496,19 @@ static void handle_swbp(struct pt_regs *regs)
                 if (!utask)
                         goto cleanup_ret;
         }
-        utask->active_uprobe = uprobe;
+
         handler_chain(uprobe, regs);
         if (uprobe->flags & UPROBE_SKIP_SSTEP && can_skip_sstep(uprobe, regs))
                 goto cleanup_ret;
 
-        utask->state = UTASK_SSTEP;
         if (!pre_ssout(uprobe, regs, bp_vaddr)) {
                 arch_uprobe_enable_step(&uprobe->arch);
+                utask->active_uprobe = uprobe;
+                utask->state = UTASK_SSTEP;
                 return;
         }
 
 cleanup_ret:
-        if (utask) {
-                utask->active_uprobe = NULL;
-                utask->state = UTASK_RUNNING;
-        }
         if (!(uprobe->flags & UPROBE_SKIP_SSTEP))
 
                 /*