Refactor IMA buffer related functions to make them reusable for carrying
TPM logs across kexec.
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
v5:
- Rebased on Jonathan McDowell's commit "b69a2afd5afc x86/kexec: Carry
forward IMA measurement log on kexec"
v4:
- Move debug output into setup_buffer()
---
drivers/of/kexec.c | 125 ++++++++++++++++++++++++++-------------------
1 file changed, 73 insertions(+), 52 deletions(-)
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 548dd5b1b5c1..404a86bb3978 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -117,45 +117,56 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
}
#ifdef CONFIG_HAVE_IMA_KEXEC
-/**
- * ima_get_kexec_buffer - get IMA buffer from the previous kernel
- * @addr: On successful return, set to point to the buffer contents.
- * @size: On successful return, set to the buffer size.
- *
- * Return: 0 on success, negative errno on error.
- */
-int __init ima_get_kexec_buffer(void **addr, size_t *size)
+static int get_kexec_buffer(const char *name, unsigned long *addr, size_t *size)
{
int ret, len;
- unsigned long tmp_addr;
unsigned long start_pfn, end_pfn;
- size_t tmp_size;
const void *prop;
- prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
+ prop = of_get_property(of_chosen, name, &len);
if (!prop)
return -ENOENT;
- ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+ ret = do_get_kexec_buffer(prop, len, addr, size);
if (ret)
return ret;
- /* Do some sanity on the returned size for the ima-kexec buffer */
- if (!tmp_size)
+ /* Do some sanity on the returned size for the kexec buffer */
+ if (!*size)
return -ENOENT;
/*
* Calculate the PFNs for the buffer and ensure
* they are with in addressable memory.
*/
- start_pfn = PHYS_PFN(tmp_addr);
- end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1);
+ start_pfn = PHYS_PFN(*addr);
+ end_pfn = PHYS_PFN(*addr + *size - 1);
if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) {
- pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n",
- tmp_addr, tmp_size);
+ pr_warn("%s buffer at 0x%lx, size = 0x%zx beyond memory\n",
+ name, *addr, *size);
return -EINVAL;
}
+ return 0;
+}
+
+/**
+ * ima_get_kexec_buffer - get IMA buffer from the previous kernel
+ * @addr: On successful return, set to point to the buffer contents.
+ * @size: On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __init ima_get_kexec_buffer(void **addr, size_t *size)
+{
+ int ret;
+ unsigned long tmp_addr;
+ size_t tmp_size;
+
+ ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size);
+ if (ret)
+ return ret;
+
*addr = __va(tmp_addr);
*size = tmp_size;
@@ -188,72 +199,82 @@ int __init ima_free_kexec_buffer(void)
}
#endif
-/**
- * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
- *
- * @fdt: Flattened Device Tree to update
- * @chosen_node: Offset to the chosen node in the device tree
- *
- * The IMA measurement buffer is of no use to a subsequent kernel, so we always
- * remove it from the device tree.
- */
-static void remove_ima_buffer(void *fdt, int chosen_node)
+static int remove_buffer(void *fdt, int chosen_node, const char *name)
{
int ret, len;
unsigned long addr;
size_t size;
const void *prop;
- if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
- return;
-
- prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
+ prop = fdt_getprop(fdt, chosen_node, name, &len);
if (!prop)
- return;
+ return -ENOENT;
ret = do_get_kexec_buffer(prop, len, &addr, &size);
- fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
+ fdt_delprop(fdt, chosen_node, name);
if (ret)
- return;
+ return ret;
ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
if (!ret)
- pr_debug("Removed old IMA buffer reservation.\n");
+ pr_debug("Remove old %s buffer reserveration", name);
+ return ret;
}
-#ifdef CONFIG_IMA_KEXEC
/**
- * setup_ima_buffer - add IMA buffer information to the fdt
- * @image: kexec image being loaded.
- * @fdt: Flattened device tree for the next kernel.
- * @chosen_node: Offset to the chosen node.
+ * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
*
- * Return: 0 on success, or negative errno on error.
+ * @fdt: Flattened Device Tree to update
+ * @chosen_node: Offset to the chosen node in the device tree
+ *
+ * The IMA measurement buffer is of no use to a subsequent kernel, so we always
+ * remove it from the device tree.
*/
-static int setup_ima_buffer(const struct kimage *image, void *fdt,
- int chosen_node)
+static void remove_ima_buffer(void *fdt, int chosen_node)
+{
+ if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+ return;
+
+ remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
+}
+
+#ifdef CONFIG_IMA_KEXEC
+static int setup_buffer(void *fdt, int chosen_node, const char *name,
+ phys_addr_t addr, size_t size)
{
int ret;
- if (!image->ima_buffer_size)
+ if (!size)
return 0;
ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
- "linux,ima-kexec-buffer",
- image->ima_buffer_addr,
- image->ima_buffer_size);
+ name, addr, size);
if (ret < 0)
return -EINVAL;
- ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
- image->ima_buffer_size);
+ ret = fdt_add_mem_rsv(fdt, addr, size);
if (ret)
return -EINVAL;
- pr_debug("IMA buffer at 0x%pa, size = 0x%zx\n",
- &image->ima_buffer_addr, image->ima_buffer_size);
+ pr_debug("%s at 0x%pa, size = 0x%zx\n", name, &addr, size);
return 0;
+
+}
+
+/**
+ * setup_ima_buffer - add IMA buffer information to the fdt
+ * @image: kexec image being loaded.
+ * @fdt: Flattened device tree for the next kernel.
+ * @chosen_node: Offset to the chosen node.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int setup_ima_buffer(const struct kimage *image, void *fdt,
+ int chosen_node)
+{
+ return setup_buffer(fdt, chosen_node, "linux,ima-kexec-buffer",
+ image->ima_buffer_addr, image->ima_buffer_size);
}
#else /* CONFIG_IMA_KEXEC */
static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
--
2.35.1
