tools/vm/slabinfo: Handle files in debugfs

commit 0c7e0d699ef1430d7f4cf12b4b1d097af58b5515 upstream.

Commit 64dd68497be76 relocated and renamed the alloc_calls and
free_calls files from /sys/kernel/slab/NAME/*_calls over to
/sys/kernel/debug/slab/NAME/*_calls but didn't update the slabinfo tool
with the new location.

This change will now have slabinfo look at the new location (and filenames)
with a fallback to the prior files.

Fixes: 64dd68497be76 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Cc: stable@vger.kernel.org
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Tested-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/vm/slabinfo.c b/tools/vm/slabinfo.c
index 9b68658..5b98f3e 100644 (file)
--- a/tools/vm/slabinfo.c
+++ b/tools/vm/slabinfo.c
@@ -233,6 +233,24 @@ static unsigned long read_slab_obj(struct slabinfo *s, const char *name)
        return l;
 }
 
+static unsigned long read_debug_slab_obj(struct slabinfo *s, const char *name)
+{
+       char x[128];
+       FILE *f;
+       size_t l;
+
+       snprintf(x, 128, "/sys/kernel/debug/slab/%s/%s", s->name, name);
+       f = fopen(x, "r");
+       if (!f) {
+               buffer[0] = 0;
+               l = 0;
+       } else {
+               l = fread(buffer, 1, sizeof(buffer), f);
+               buffer[l] = 0;
+               fclose(f);
+       }
+       return l;
+}
 
 /*
  * Put a size string together
@@ -409,14 +427,18 @@ static void show_tracking(struct slabinfo *s)
 {
        printf("\n%s: Kernel object allocation\n", s->name);
        printf("-----------------------------------------------------------------------\n");
-       if (read_slab_obj(s, "alloc_calls"))
+       if (read_debug_slab_obj(s, "alloc_traces"))
+               printf("%s", buffer);
+       else if (read_slab_obj(s, "alloc_calls"))
                printf("%s", buffer);
        else
                printf("No Data\n");
 
        printf("\n%s: Kernel object freeing\n", s->name);
        printf("------------------------------------------------------------------------\n");
-       if (read_slab_obj(s, "free_calls"))
+       if (read_debug_slab_obj(s, "free_traces"))
+               printf("%s", buffer);
+       else if (read_slab_obj(s, "free_calls"))
                printf("%s", buffer);
        else
                printf("No Data\n");