uprobes: Introduce MMF_RECALC_UPROBES
Add the new MMF_RECALC_UPROBES flag, it means that MMF_HAS_UPROBES
can be false positive after remove_breakpoint() or uprobe_munmap().
It is also set by uprobe_dup_mmap(), this is not optimal but simple.
We could add the new hook, uprobe_dup_vma(), to set MMF_HAS_UPROBES
only if the new mm actually has uprobes, but I don't think this
makes sense.
The next patch will use this flag to clear MMF_HAS_UPROBES.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3667c332..255661d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -446,7 +446,8 @@
#define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
-#define MMF_HAS_UPROBES 19 /* might have uprobes */
+#define MMF_HAS_UPROBES 19 /* has uprobes */
+#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)