perf/core: Fix PERF_RECORD_MMAP2 prot/flags for anonymous memory

commit 0b3589be9b98994ce3d5aeca52445d1f5627c4ba upstream.

Andres reported that MMAP2 records for anonymous memory always have
their protection field 0.

Turns out, someone daft put the prot/flags generation code in the file
branch, leaving them unset for anonymous memory.

Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Don Zickus <dzickus@redhat.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: anton@ozlabs.org
Cc: namhyung@kernel.org
Fixes: f972eb63b100 ("perf: Pass protection and flags bits through mmap2 interface")
Link: http://lkml.kernel.org/r/20170126221508.GF6536@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 21 insertions, 21 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6e440c4d17fe..b1cfd7416db0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6606,6 +6606,27 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
         char *buf = NULL;
         char *name;
 
+        if (vma->vm_flags & VM_READ)
+                prot |= PROT_READ;
+        if (vma->vm_flags & VM_WRITE)
+                prot |= PROT_WRITE;
+        if (vma->vm_flags & VM_EXEC)
+                prot |= PROT_EXEC;
+
+        if (vma->vm_flags & VM_MAYSHARE)
+                flags = MAP_SHARED;
+        else
+                flags = MAP_PRIVATE;
+
+        if (vma->vm_flags & VM_DENYWRITE)
+                flags |= MAP_DENYWRITE;
+        if (vma->vm_flags & VM_MAYEXEC)
+                flags |= MAP_EXECUTABLE;
+        if (vma->vm_flags & VM_LOCKED)
+                flags |= MAP_LOCKED;
+        if (vma->vm_flags & VM_HUGETLB)
+                flags |= MAP_HUGETLB;
+
         if (file) {
                 struct inode *inode;
                 dev_t dev;
@@ -6632,27 +6653,6 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
                 maj = MAJOR(dev);
                 min = MINOR(dev);
 
-                if (vma->vm_flags & VM_READ)
-                        prot |= PROT_READ;
-                if (vma->vm_flags & VM_WRITE)
-                        prot |= PROT_WRITE;
-                if (vma->vm_flags & VM_EXEC)
-                        prot |= PROT_EXEC;
-
-                if (vma->vm_flags & VM_MAYSHARE)
-                        flags = MAP_SHARED;
-                else
-                        flags = MAP_PRIVATE;
-
-                if (vma->vm_flags & VM_DENYWRITE)
-                        flags |= MAP_DENYWRITE;
-                if (vma->vm_flags & VM_MAYEXEC)
-                        flags |= MAP_EXECUTABLE;
-                if (vma->vm_flags & VM_LOCKED)
-                        flags |= MAP_LOCKED;
-                if (vma->vm_flags & VM_HUGETLB)
-                        flags |= MAP_HUGETLB;
-
                 goto got_name;
         } else {
                 if (vma->vm_ops && vma->vm_ops->name) {