[PATCH 25/33] efi/libstub: Move efi_relocate_kernel() into separate source file

Ard Biesheuvel
2020-04-24T13:07:45Z

Move efi_relocate_kernel() into a separate source file, so that it
only gets pulled into builds for architectures that use it. Since
efi_relocate_kernel() is the only user of efi_low_alloc(), let's
move that over as well.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
drivers/firmware/efi/libstub/Makefile | 2 +-
drivers/firmware/efi/libstub/efistub.h | 15 --
drivers/firmware/efi/libstub/mem.c | 168 -----------------------
drivers/firmware/efi/libstub/relocate.c | 174 ++++++++++++++++++++++++
4 files changed, 175 insertions(+), 184 deletions(-)
create mode 100644 drivers/firmware/efi/libstub/relocate.c

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index bb8af2b16c49..9a712a6e2f87 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -43,7 +43,7 @@ KCOV_INSTRUMENT := n
lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
file.o mem.o random.o randomalloc.o pci.o \
skip_spaces.o lib-cmdline.o lib-ctype.o \
- alignedmem.o
+ alignedmem.o relocate.o

# include the stub's generic dependencies from lib/ when building for ARM/arm64
efi-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index baa0bc166074..2a0698d9dc78 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -639,21 +639,6 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len,

efi_status_t efi_get_memory_map(struct efi_boot_memmap *map);

-efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
- unsigned long *addr, unsigned long min);
-
-static inline
-efi_status_t efi_low_alloc(unsigned long size, unsigned long align,
- unsigned long *addr)
-{
- /*
- * Don't allocate at 0x0. It will confuse code that
- * checks pointers against NULL. Skip the first 8
- * bytes so we start at a nice even number.
- */
- return efi_low_alloc_above(size, align, addr, 0x8);
-}
-
efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
unsigned long max);

diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c
index 0020b0fa9587..6e0ee6b3d897 100644
--- a/drivers/firmware/efi/libstub/mem.c
+++ b/drivers/firmware/efi/libstub/mem.c
@@ -111,96 +111,6 @@ efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
return EFI_SUCCESS;
}

-/**
- * efi_low_alloc_above() - allocate pages at or above given address
- * @size: size of the memory area to allocate
- * @align: minimum alignment of the allocated memory area. It should
- * a power of two.
- * @addr: on exit the address of the allocated memory
- * @min: minimum address to used for the memory allocation
- *
- * Allocate at the lowest possible address that is not below @min as
- * EFI_LOADER_DATA. The allocated pages are aligned according to @align but at
- * least EFI_ALLOC_ALIGN. The first allocated page will not below the address
- * given by @min.
- *
- * Return: status code
- */
-efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
- unsigned long *addr, unsigned long min)
-{
- unsigned long map_size, desc_size, buff_size;
- efi_memory_desc_t *map;
- efi_status_t status;
- unsigned long nr_pages;
- int i;
- struct efi_boot_memmap boot_map;
-
- boot_map.map = &map;
- boot_map.map_size = &map_size;
- boot_map.desc_size = &desc_size;
- boot_map.desc_ver = NULL;
- boot_map.key_ptr = NULL;
- boot_map.buff_size = &buff_size;
-
- status = efi_get_memory_map(&boot_map);
- if (status != EFI_SUCCESS)
- goto fail;
-
- /*
- * Enforce minimum alignment that EFI or Linux requires when
- * requesting a specific address. We are doing page-based (or
- * larger) allocations, and both the address and size must meet
- * alignment constraints.
- */
- if (align < EFI_ALLOC_ALIGN)
- align = EFI_ALLOC_ALIGN;
-
- size = round_up(size, EFI_ALLOC_ALIGN);
- nr_pages = size / EFI_PAGE_SIZE;
- for (i = 0; i < map_size / desc_size; i++) {
- efi_memory_desc_t *desc;
- unsigned long m = (unsigned long)map;
- u64 start, end;
-
- desc = efi_early_memdesc_ptr(m, desc_size, i);
-
- if (desc->type != EFI_CONVENTIONAL_MEMORY)
- continue;
-
- if (efi_soft_reserve_enabled() &&
- (desc->attribute & EFI_MEMORY_SP))
- continue;
-
- if (desc->num_pages < nr_pages)
- continue;
-
- start = desc->phys_addr;
- end = start + desc->num_pages * EFI_PAGE_SIZE;
-
- if (start < min)
- start = min;
-
- start = round_up(start, align);
- if ((start + size) > end)
- continue;
-
- status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
- EFI_LOADER_DATA, nr_pages, &start);
- if (status == EFI_SUCCESS) {
- *addr = start;
- break;
- }
- }
-
- if (i == map_size / desc_size)
- status = EFI_NOT_FOUND;
-
- efi_bs_call(free_pool, map);
-fail:
- return status;
-}
-
/**
* efi_free() - free memory pages
* @size: size of the memory area to free in bytes
@@ -222,81 +132,3 @@ void efi_free(unsigned long size, unsigned long addr)
nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
efi_bs_call(free_pages, addr, nr_pages);
}
-
-/**
- * efi_relocate_kernel() - copy memory area
- * @image_addr: pointer to address of memory area to copy
- * @image_size: size of memory area to copy
- * @alloc_size: minimum size of memory to allocate, must be greater or
- * equal to image_size
- * @preferred_addr: preferred target address
- * @alignment: minimum alignment of the allocated memory area. It
- * should be a power of two.
- * @min_addr: minimum target address
- *
- * Copy a memory area to a newly allocated memory area aligned according
- * to @alignment but at least EFI_ALLOC_ALIGN. If the preferred address
- * is not available, the allocated address will not be below @min_addr.
- * On exit, @image_addr is updated to the target copy address that was used.
- *
- * This function is used to copy the Linux kernel verbatim. It does not apply
- * any relocation changes.
- *
- * Return: status code
- */
-efi_status_t efi_relocate_kernel(unsigned long *image_addr,
- unsigned long image_size,
- unsigned long alloc_size,
- unsigned long preferred_addr,
- unsigned long alignment,
- unsigned long min_addr)
-{
- unsigned long cur_image_addr;
- unsigned long new_addr = 0;
- efi_status_t status;
- unsigned long nr_pages;
- efi_physical_addr_t efi_addr = preferred_addr;
-
- if (!image_addr || !image_size || !alloc_size)
- return EFI_INVALID_PARAMETER;
- if (alloc_size < image_size)
- return EFI_INVALID_PARAMETER;
-
- cur_image_addr = *image_addr;
-
- /*
- * The EFI firmware loader could have placed the kernel image
- * anywhere in memory, but the kernel has restrictions on the
- * max physical address it can run at. Some architectures
- * also have a prefered address, so first try to relocate
- * to the preferred address. If that fails, allocate as low
- * as possible while respecting the required alignment.
- */
- nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
- status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
- EFI_LOADER_DATA, nr_pages, &efi_addr);
- new_addr = efi_addr;
- /*
- * If preferred address allocation failed allocate as low as
- * possible.
- */
- if (status != EFI_SUCCESS) {
- status = efi_low_alloc_above(alloc_size, alignment, &new_addr,
- min_addr);
- }
- if (status != EFI_SUCCESS) {
- pr_efi_err("Failed to allocate usable memory for kernel.\n");
- return status;
- }
-
- /*
- * We know source/dest won't overlap since both memory ranges
- * have been allocated by UEFI, so we can safely use memcpy.
- */
- memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
-
- /* Return the new address of the relocated image. */
- *image_addr = new_addr;
-
- return status;
-}
diff --git a/drivers/firmware/efi/libstub/relocate.c b/drivers/firmware/efi/libstub/relocate.c
new file mode 100644
index 000000000000..1507d3c82884
--- /dev/null
+++ b/drivers/firmware/efi/libstub/relocate.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+/**
+ * efi_low_alloc_above() - allocate pages at or above given address
+ * @size: size of the memory area to allocate
+ * @align: minimum alignment of the allocated memory area. It should
+ * a power of two.
+ * @addr: on exit the address of the allocated memory
+ * @min: minimum address to used for the memory allocation
+ *
+ * Allocate at the lowest possible address that is not below @min as
+ * EFI_LOADER_DATA. The allocated pages are aligned according to @align but at
+ * least EFI_ALLOC_ALIGN. The first allocated page will not below the address
+ * given by @min.
+ *
+ * Return: status code
+ */
+static efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
+ unsigned long *addr, unsigned long min)
+{
+ unsigned long map_size, desc_size, buff_size;
+ efi_memory_desc_t *map;
+ efi_status_t status;
+ unsigned long nr_pages;
+ int i;
+ struct efi_boot_memmap boot_map;
+
+ boot_map.map = &map;
+ boot_map.map_size = &map_size;
+ boot_map.desc_size = &desc_size;
+ boot_map.desc_ver = NULL;
+ boot_map.key_ptr = NULL;
+ boot_map.buff_size = &buff_size;
+
+ status = efi_get_memory_map(&boot_map);
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ /*
+ * Enforce minimum alignment that EFI or Linux requires when
+ * requesting a specific address. We are doing page-based (or
+ * larger) allocations, and both the address and size must meet
+ * alignment constraints.
+ */
+ if (align < EFI_ALLOC_ALIGN)
+ align = EFI_ALLOC_ALIGN;
+
+ size = round_up(size, EFI_ALLOC_ALIGN);
+ nr_pages = size / EFI_PAGE_SIZE;
+ for (i = 0; i < map_size / desc_size; i++) {
+ efi_memory_desc_t *desc;
+ unsigned long m = (unsigned long)map;
+ u64 start, end;
+
+ desc = efi_early_memdesc_ptr(m, desc_size, i);
+
+ if (desc->type != EFI_CONVENTIONAL_MEMORY)
+ continue;
+
+ if (efi_soft_reserve_enabled() &&
+ (desc->attribute & EFI_MEMORY_SP))
+ continue;
+
+ if (desc->num_pages < nr_pages)
+ continue;
+
+ start = desc->phys_addr;
+ end = start + desc->num_pages * EFI_PAGE_SIZE;
+
+ if (start < min)
+ start = min;
+
+ start = round_up(start, align);
+ if ((start + size) > end)
+ continue;
+
+ status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
+ EFI_LOADER_DATA, nr_pages, &start);
+ if (status == EFI_SUCCESS) {
+ *addr = start;
+ break;
+ }
+ }
+
+ if (i == map_size / desc_size)
+ status = EFI_NOT_FOUND;
+
+ efi_bs_call(free_pool, map);
+fail:
+ return status;
+}
+
+/**
+ * efi_relocate_kernel() - copy memory area
+ * @image_addr: pointer to address of memory area to copy
+ * @image_size: size of memory area to copy
+ * @alloc_size: minimum size of memory to allocate, must be greater or
+ * equal to image_size
+ * @preferred_addr: preferred target address
+ * @alignment: minimum alignment of the allocated memory area. It
+ * should be a power of two.
+ * @min_addr: minimum target address
+ *
+ * Copy a memory area to a newly allocated memory area aligned according
+ * to @alignment but at least EFI_ALLOC_ALIGN. If the preferred address
+ * is not available, the allocated address will not be below @min_addr.
+ * On exit, @image_addr is updated to the target copy address that was used.
+ *
+ * This function is used to copy the Linux kernel verbatim. It does not apply
+ * any relocation changes.
+ *
+ * Return: status code
+ */
+efi_status_t efi_relocate_kernel(unsigned long *image_addr,
+ unsigned long image_size,
+ unsigned long alloc_size,
+ unsigned long preferred_addr,
+ unsigned long alignment,
+ unsigned long min_addr)
+{
+ unsigned long cur_image_addr;
+ unsigned long new_addr = 0;
+ efi_status_t status;
+ unsigned long nr_pages;
+ efi_physical_addr_t efi_addr = preferred_addr;
+
+ if (!image_addr || !image_size || !alloc_size)
+ return EFI_INVALID_PARAMETER;
+ if (alloc_size < image_size)
+ return EFI_INVALID_PARAMETER;
+
+ cur_image_addr = *image_addr;
+
+ /*
+ * The EFI firmware loader could have placed the kernel image
+ * anywhere in memory, but the kernel has restrictions on the
+ * max physical address it can run at. Some architectures
+ * also have a prefered address, so first try to relocate
+ * to the preferred address. If that fails, allocate as low
+ * as possible while respecting the required alignment.
+ */
+ nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
+ status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
+ EFI_LOADER_DATA, nr_pages, &efi_addr);
+ new_addr = efi_addr;
+ /*
+ * If preferred address allocation failed allocate as low as
+ * possible.
+ */
+ if (status != EFI_SUCCESS) {
+ status = efi_low_alloc_above(alloc_size, alignment, &new_addr,
+ min_addr);
+ }
+ if (status != EFI_SUCCESS) {
+ pr_efi_err("Failed to allocate usable memory for kernel.\n");
+ return status;
+ }
+
+ /*
+ * We know source/dest won't overlap since both memory ranges
+ * have been allocated by UEFI, so we can safely use memcpy.
+ */
+ memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
+
+ /* Return the new address of the relocated image. */
+ *image_addr = new_addr;
+
+ return status;
+}
--
2.17.1