[PATCH 12/14] efi/capsule-loader: Redirect calls to efi_capsule_setup_info() via weak alias


Jan Kiszka
 

From: Ard Biesheuvel <ard.biesheuvel@...>

commit 3fabd628d5ea24b02ddb1230ffca1df0f779f84e upstream.

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@...>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...>
Cc: Linus Torvalds <torvalds@...>
Cc: Matt Fleming <matt@...>
Cc: Peter Zijlstra <peterz@...>
Cc: Thomas Gleixner <tglx@...>
Cc: linux-efi@...
Link: http://lkml.kernel.org/r/20170602135207.21708-9-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@...>
---
drivers/firmware/efi/capsule-loader.c | 56 +++++++++++++++++------------------
include/linux/efi.h | 12 ++++++++
2 files changed, 39 insertions(+), 29 deletions(-)

diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c
index 5b012a467d7d..f7fdeab0bc37 100644
--- 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);
@@ -97,6 +71,30 @@ static int efi_capsule_setup_info(struct capsule_info *cap_info,
}

/**
+ * 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
* @cap_info: pointer to current instance of capsule_info structure
@@ -186,7 +184,7 @@ 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 5a0b8f7a54c8..b386097e45bc 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -129,6 +129,18 @@ typedef struct {
#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.
*/
--
2.12.3

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