Fixup some memory tapset vm kernel function probe fallbacks.

Older kernels don't have all GFP constants defined, and the fallback
kernel function probe fallbacks don't have the same dwarf variable
names as the kernel trace point probes. So replace them with variables
that are available. bytes_alloc was sometimes a long and sometimes a
string, this caused scripts to fail depending on which alternative was
chosen for a particular kernel. So make it a long always.
This isn't a full solution since kmalloc is always inlined which makes
the kernel.function("kmalloc").return probe fail.

* tapset/memory.stp: Define __GFP_THISNODE, __GFP_RECLAIMABLE,
  GFP_TEMPORARY, GFP_HIGHUSER_MOVABLE and GFP_THISNODE when not yet
  defined.
  (__vm.kmalloc.kp): Use $flags, not $gfp_flags. Set bytes_alloc equal
  to bytes_req.
  (__vm.kmem_cache_alloc.kp): Likewise. And use $cachep->buffer_size
  for bytes_req.
  (__vm.kmalloc_node.kp): Likewise.
  (__vm.kmem_cache_alloc_node.kp): Likewise.
  (__vm.kfree.kp): Use $ibjp for ptr, not $return.
  (__vm.kmem_cache_free.kp): Likewise.
* testsuite/buildok/vm.tracepoints.stp: Move vm.kmalloc test to...
* testsuite/buildok/vm.tracepoints.kmalloc.stp: ... here.

3 files changed, 53 insertions, 20 deletions

diff --git a/tapset/memory.stp b/tapset/memory.stp
index bd71a386..c170c5c7 100644
--- a/tapset/memory.stp
+++ b/tapset/memory.stp
@@ -217,6 +217,33 @@ function __gfp_flag_str:string(gfp_flag:long) %{
 #endif
 #endif
 
+#ifndef __GFP_THISNODE
+#define __GFP_THISNODE  ((__force gfp_t)0x40000u)
+#endif
+
+#ifndef __GFP_RECLAIMABLE
+#define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u)
+#endif
+
+#ifndef GFP_TEMPORARY
+#define GFP_TEMPORARY  (__GFP_WAIT | __GFP_IO | __GFP_FS | \
+                        __GFP_RECLAIMABLE)
+#endif
+
+#ifndef GFP_HIGHUSER_MOVABLE
+#define GFP_HIGHUSER_MOVABLE   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
+                                __GFP_HARDWALL | __GFP_HIGHMEM | \
+                                __GFP_MOVABLE)
+#endif
+
+#ifndef GFP_THISNODE
+#ifdef CONFIG_NUMA
+#define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
+#else
+#define GFP_THISNODE    ((__force gfp_t)0)
+#endif
+#endif
+
 /* Macro for GFP Bitmasks. */
 /* The resulted GFP_FLAGS may be either single or concatenation of the multiple bitmasks. */
 
@@ -298,9 +325,9 @@ probe __vm.kmalloc.kp = kernel.function("kmalloc").return {
 	call_site = 0
 	caller_function = "unknown"
 	bytes_req = $size
-	bytes_alloc = "unknown"
-	gfp_flags = $gfp_flags
-	gfp_flag_name = __gfp_flag_str($gfp_flags)
+	bytes_alloc = bytes_req // pretend they are always the same
+	gfp_flags = $flags
+	gfp_flag_name = __gfp_flag_str(gfp_flags)
 	ptr = $return
 }
 
@@ -334,10 +361,10 @@ probe __vm.kmem_cache_alloc.kp = kernel.function("kmem_cache_alloc").return {
 	name = "kmem_cache_alloc"
 	call_site = 0
 	caller_function = "unknown"
-	bytes_req = $size
-	bytes_alloc = "unknown"
-	gfp_flags = $gfp_flags
-	gfp_flag_name = __gfp_flag_str($gfp_flags)
+	bytes_req = $cachep->buffer_size
+	bytes_alloc = bytes_req // pretend they are always the same
+	gfp_flags = $flags
+	gfp_flag_name = __gfp_flag_str(gfp_flags)
 	ptr = $return
 }
 
@@ -373,9 +400,9 @@ probe __vm.kmalloc_node.kp = kernel.function("kmalloc_node").return? {
 	call_site = 0
 	caller_function = "unknown"
 	bytes_req = $size
-	bytes_alloc = "unknown"
-	gfp_flags = $gfp_flags
-	gfp_flag_name = __gfp_flag_str($gfp_flags)
+	bytes_alloc = bytes_req // pretend they are always the same
+	gfp_flags = $flags
+	gfp_flag_name = __gfp_flag_str(gfp_flags)
 	ptr = $return
 }
 
@@ -408,10 +435,10 @@ probe __vm.kmem_cache_alloc_node.kp = kernel.function("kmem_cache_alloc_node").r
 	name = "kmem_cache_alloc_node"
 	call_site = 0
 	caller_function = "unknown"
-	bytes_req = $size
-	bytes_alloc = "unknown"
-	gfp_flags = $gfp_flags
-	gfp_flag_name = __gfp_flag_str($gfp_flags)
+	bytes_req = $cachep->buffer_size
+	bytes_alloc = bytes_req // pretend they are always the same
+	gfp_flags = $flags
+	gfp_flag_name = __gfp_flag_str(gfp_flags)
 	ptr = $return
 }
 
@@ -442,7 +469,7 @@ probe __vm.kfree.kp = kernel.function("kfree").return {
 	name = "kfree"
 	call_site = 0
 	caller_function = "unknown"
-	ptr = $return
+	ptr = $objp
 }
 
 /**
@@ -465,7 +492,7 @@ probe __vm.kmem_cache_free.kp = kernel.function("kmem_cache_free").return {
 	name = "kmem_cache_free"
 	call_site = 0
 	caller_function = "unknown"
-	ptr = $return
+	ptr = $objp
 }
 /**
  * probe vm.kmem_cache_free - Fires when \
diff --git a/testsuite/buildok/vm.tracepoints.kmalloc.stp b/testsuite/buildok/vm.tracepoints.kmalloc.stp
new file mode 100644
index 00000000..f723737c
--- /dev/null
+++ b/testsuite/buildok/vm.tracepoints.kmalloc.stp
@@ -0,0 +1,9 @@
+#! stap -up4
+
+/* All other tracepoint memory probes are in another test vm.tracepoints.stp */
+
+probe vm.kmalloc {
+        println(name)
+        printf("%-15s %-15p %-15s %-15p %-15d %-15d %-15d %-15s \n", execname(), call_site, caller_function, ptr, bytes_req, bytes_alloc, gfp_flags, gfp_flag_name)
+}
+
diff --git a/testsuite/buildok/vm.tracepoints.stp b/testsuite/buildok/vm.tracepoints.stp
index 488ca0fc..6ed747d7 100644
--- a/testsuite/buildok/vm.tracepoints.stp
+++ b/testsuite/buildok/vm.tracepoints.stp
@@ -5,10 +5,7 @@ probe vm.kfree {
         printf("%-15s %-15p %-15s %-15p \n", execname(), call_site, caller_function, ptr)
 }
 
-probe vm.kmalloc {
-        println(name)
-        printf("%-15s %-15p %-15s %-15p %-15d %-15d %-15d %-15s \n", execname(), call_site, caller_function, ptr, bytes_req, bytes_alloc, gfp_flags, gfp_flag_name)
-}
+/* vm.kmalloc is in a separate test vm.tracepoints.kmalloc.stp */
 
 probe vm.kmem_cache_alloc {
         println(name)