efi/capsule-loader: Redirect calls to efi_capsule_setup_info() via weak alias

To allow platform specific code to hook into the capsule loading
routines, indirect calls to efi_capsule_setup_info() via a weak alias
of __efi_capsule_setup_info(), allowing platforms to redefine the former
but still use the latter.

Tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170602135207.21708-9-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c
index 2357bcdcb44d1d6e24517f4dc35e826bf00217c6..cbc3526953d5b665e4dbda5fb1f72c6e0efd8060 100644 (file)
--- a/drivers/firmware/efi/capsule-loader.c
+++ b/drivers/firmware/efi/capsule-loader.c
@@ -20,16 +20,6 @@
 
 #define NO_FURTHER_WRITE_ACTION -1
 
-struct capsule_info {
-       efi_capsule_header_t    header;
-       int                     reset_type;
-       long                    index;
-       size_t                  count;
-       size_t                  total_size;
-       struct page             **pages;
-       size_t                  page_bytes_remain;
-};
-
 /**
  * efi_free_all_buff_pages - free all previous allocated buffer pages
  * @cap_info: pointer to current instance of capsule_info structure
@@ -46,28 +36,13 @@ static void efi_free_all_buff_pages(struct capsule_info *cap_info)
        cap_info->index = NO_FURTHER_WRITE_ACTION;
 }
 
-/**
- * efi_capsule_setup_info - obtain the efi capsule header in the binary and
- *                         setup capsule_info structure
- * @cap_info: pointer to current instance of capsule_info structure
- * @kbuff: a mapped first page buffer pointer
- * @hdr_bytes: the total received number of bytes for efi header
- **/
-static int efi_capsule_setup_info(struct capsule_info *cap_info,
-                                 void *kbuff, size_t hdr_bytes)
+int __efi_capsule_setup_info(struct capsule_info *cap_info)
 {
        size_t pages_needed;
        int ret;
        void *temp_page;
 
-       /* Only process data block that is larger than efi header size */
-       if (hdr_bytes < sizeof(efi_capsule_header_t))
-               return 0;
-
-       /* Reset back to the correct offset of header */
-       kbuff -= cap_info->count;
-       memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
-       pages_needed = ALIGN(cap_info->header.imagesize, PAGE_SIZE) / PAGE_SIZE;
+       pages_needed = ALIGN(cap_info->total_size, PAGE_SIZE) / PAGE_SIZE;
 
        if (pages_needed == 0) {
                pr_err("invalid capsule size");
@@ -84,7 +59,6 @@ static int efi_capsule_setup_info(struct capsule_info *cap_info,
                return ret;
        }
 
-       cap_info->total_size = cap_info->header.imagesize;
        temp_page = krealloc(cap_info->pages,
                             pages_needed * sizeof(void *),
                             GFP_KERNEL | __GFP_ZERO);
@@ -96,6 +70,30 @@ static int efi_capsule_setup_info(struct capsule_info *cap_info,
        return 0;
 }
 
+/**
+ * efi_capsule_setup_info - obtain the efi capsule header in the binary and
+ *                         setup capsule_info structure
+ * @cap_info: pointer to current instance of capsule_info structure
+ * @kbuff: a mapped first page buffer pointer
+ * @hdr_bytes: the total received number of bytes for efi header
+ *
+ * Platforms with non-standard capsule update mechanisms can override
+ * this __weak function so they can perform any required capsule
+ * image munging. See quark_quirk_function() for an example.
+ **/
+int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
+                                 size_t hdr_bytes)
+{
+       /* Only process data block that is larger than efi header size */
+       if (hdr_bytes < sizeof(efi_capsule_header_t))
+               return 0;
+
+       memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
+       cap_info->total_size = cap_info->header.imagesize;
+
+       return __efi_capsule_setup_info(cap_info);
+}
+
 /**
  * efi_capsule_submit_update - invoke the efi_capsule_update API once binary
  *                            upload done
@@ -182,7 +180,7 @@ static ssize_t efi_capsule_write(struct file *file, const char __user *buff,
 
        /* Setup capsule binary info structure */
        if (cap_info->header.headersize == 0) {
-               ret = efi_capsule_setup_info(cap_info, kbuff,
+               ret = efi_capsule_setup_info(cap_info, kbuff - cap_info->count,
                                             cap_info->count + write_byte);
                if (ret)
                        goto fail_unmap;

diff --git a/include/linux/efi.h b/include/linux/efi.h
index ec36f42a2adde07cd9ca9b37ddaaf9442dccee31..a7379a2b5680bbb509911841c032b99c6e0d2504 100644 (file)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -137,6 +137,18 @@ struct efi_boot_memmap {
 #define EFI_CAPSULE_POPULATE_SYSTEM_TABLE      0x00020000
 #define EFI_CAPSULE_INITIATE_RESET             0x00040000
 
+struct capsule_info {
+       efi_capsule_header_t    header;
+       int                     reset_type;
+       long                    index;
+       size_t                  count;
+       size_t                  total_size;
+       struct page             **pages;
+       size_t                  page_bytes_remain;
+};
+
+int __efi_capsule_setup_info(struct capsule_info *cap_info);
+
 /*
  * Allocation types for calls to boottime->allocate_pages.
  */