From: Michael Jeanson <mjeanson@efficios.com>
Date: Tue, 7 Jul 2020 15:58:03 +0000 (-0400)
Subject: fix: prior to v4.0, __vmalloc_node_range had no vm_flags param
X-Git-Tag: v2.11.5~10
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=24b1dd9405ea4c7af7ed3a2f7bf3824a43c1bbca;p=lttng-modules.git

fix: prior to v4.0, __vmalloc_node_range had no vm_flags param

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ib476e32d109298d9ca3e6b6ab7ac8f63c50fb09f
---

diff --git a/wrapper/vmalloc.h b/wrapper/vmalloc.h
index 21e9bda2..5901ef32 100644
--- a/wrapper/vmalloc.h
+++ b/wrapper/vmalloc.h
@@ -212,6 +212,8 @@ void print_vmalloc_node_range_warning(void)
 	printk_once(KERN_WARNING "Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
 }
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0))
+
 /*
  * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
  */
@@ -260,6 +262,56 @@ void *__canary____lttng_vmalloc_node_range(unsigned long size, unsigned long ali
 			vm_flags, node, caller);
 }
 
+#else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0)) */
+
+/*
+ * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
+ */
+static inline
+void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
+			unsigned long start, unsigned long end, gfp_t gfp_mask,
+			pgprot_t prot, unsigned long vm_flags, int node,
+			const void *caller)
+{
+#ifdef CONFIG_KALLSYMS
+	/*
+	 * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
+	 */
+	void *(*lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
+			unsigned long start, unsigned long end, gfp_t gfp_mask,
+			pgprot_t prot, int node, const void *caller);
+
+	lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
+	if (lttng__vmalloc_node_range)
+		return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
+				node, caller);
+#endif
+	if (node != NUMA_NO_NODE)
+		print_vmalloc_node_range_warning();
+	return __vmalloc(size, gfp_mask, prot);
+}
+
+/*
+ * Canary function to check for '__vmalloc_node_range()' at compile time.
+ *
+ * From 'include/linux/vmalloc.h':
+ *
+ *   extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
+ *                           unsigned long start, unsigned long end, gfp_t gfp_mask,
+ *                           pgprot_t prot, unsigned long vm_flags, int node,
+ *                           const void *caller);
+ */
+static inline
+void *__canary____lttng_vmalloc_node_range(unsigned long size, unsigned long align,
+			unsigned long start, unsigned long end, gfp_t gfp_mask,
+			pgprot_t prot, int node, const void *caller)
+{
+	return __vmalloc_node_range(size, align, start, end, gfp_mask, prot,
+			node, caller);
+}
+
+#endif
+
 /**
  * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
  * failure, fall back to non-contiguous (vmalloc) allocation.