From: Ard Biesheuvel <ardb@kernel.org>
Date: Mon, 10 Feb 2020 17:02:41 +0100
Subject: efi/libstub: Move efi_random_alloc() into separate source file
Patch-mainline: v5.7-rc1
Git-commit: 0ed02bdaa7d8d93157a7055a23b03774c930f561
References: jsc#SLE-16407
efi_random_alloc() is only used on arm64, but as it shares a source
file with efi_random_get_seed(), the latter will pull in the former
on other architectures as well.
Let's take advantage of the fact that libstub is a static library,
and so the linker will only incorporate objects that are needed to
satisfy dependencies in other objects. This means we can move the
random alloc code to a separate source file that gets built
unconditionally, but only used when needed.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
drivers/firmware/efi/libstub/Makefile | 2
drivers/firmware/efi/libstub/random.c | 114 --------------------------
drivers/firmware/efi/libstub/randomalloc.c | 124 +++++++++++++++++++++++++++++
3 files changed, 125 insertions(+), 115 deletions(-)
create mode 100644 drivers/firmware/efi/libstub/randomalloc.c
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -40,7 +40,7 @@ OBJECT_FILES_NON_STANDARD := y
KCOV_INSTRUMENT := n
lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
- mem.o random.o pci.o
+ mem.o random.o randomalloc.o pci.o
# include the stub's generic dependencies from lib/ when building for ARM/arm64
arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
--- a/drivers/firmware/efi/libstub/random.c
+++ b/drivers/firmware/efi/libstub/random.c
@@ -4,7 +4,6 @@
*/
#include <linux/efi.h>
-#include <linux/log2.h>
#include <asm/efi.h>
#include "efistub.h"
@@ -39,119 +38,6 @@ efi_status_t efi_get_random_bytes(unsign
return efi_call_proto(rng, get_rng, NULL, size, out);
}
-/*
- * Return the number of slots covered by this entry, i.e., the number of
- * addresses it covers that are suitably aligned and supply enough room
- * for the allocation.
- */
-static unsigned long get_entry_num_slots(efi_memory_desc_t *md,
- unsigned long size,
- unsigned long align_shift)
-{
- unsigned long align = 1UL << align_shift;
- u64 first_slot, last_slot, region_end;
-
- if (md->type != EFI_CONVENTIONAL_MEMORY)
- return 0;
-
- if (efi_soft_reserve_enabled() &&
- (md->attribute & EFI_MEMORY_SP))
- return 0;
-
- region_end = min((u64)ULONG_MAX, md->phys_addr + md->num_pages*EFI_PAGE_SIZE - 1);
-
- first_slot = round_up(md->phys_addr, align);
- last_slot = round_down(region_end - size + 1, align);
-
- if (first_slot > last_slot)
- return 0;
-
- return ((unsigned long)(last_slot - first_slot) >> align_shift) + 1;
-}
-
-/*
- * The UEFI memory descriptors have a virtual address field that is only used
- * when installing the virtual mapping using SetVirtualAddressMap(). Since it
- * is unused here, we can reuse it to keep track of each descriptor's slot
- * count.
- */
-#define MD_NUM_SLOTS(md) ((md)->virt_addr)
-
-efi_status_t efi_random_alloc(unsigned long size,
- unsigned long align,
- unsigned long *addr,
- unsigned long random_seed)
-{
- unsigned long map_size, desc_size, total_slots = 0, target_slot;
- unsigned long buff_size;
- efi_status_t status;
- efi_memory_desc_t *memory_map;
- int map_offset;
- struct efi_boot_memmap map;
-
- map.map = &memory_map;
- map.map_size = &map_size;
- map.desc_size = &desc_size;
- map.desc_ver = NULL;
- map.key_ptr = NULL;
- map.buff_size = &buff_size;
-
- status = efi_get_memory_map(&map);
- if (status != EFI_SUCCESS)
- return status;
-
- if (align < EFI_ALLOC_ALIGN)
- align = EFI_ALLOC_ALIGN;
-
- /* count the suitable slots in each memory map entry */
- for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
- efi_memory_desc_t *md = (void *)memory_map + map_offset;
- unsigned long slots;
-
- slots = get_entry_num_slots(md, size, ilog2(align));
- MD_NUM_SLOTS(md) = slots;
- total_slots += slots;
- }
-
- /* find a random number between 0 and total_slots */
- target_slot = (total_slots * (u16)random_seed) >> 16;
-
- /*
- * target_slot is now a value in the range [0, total_slots), and so
- * it corresponds with exactly one of the suitable slots we recorded
- * when iterating over the memory map the first time around.
- *
- * So iterate over the memory map again, subtracting the number of
- * slots of each entry at each iteration, until we have found the entry
- * that covers our chosen slot. Use the residual value of target_slot
- * to calculate the randomly chosen address, and allocate it directly
- * using EFI_ALLOCATE_ADDRESS.
- */
- for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
- efi_memory_desc_t *md = (void *)memory_map + map_offset;
- efi_physical_addr_t target;
- unsigned long pages;
-
- if (target_slot >= MD_NUM_SLOTS(md)) {
- target_slot -= MD_NUM_SLOTS(md);
- continue;
- }
-
- target = round_up(md->phys_addr, align) + target_slot * align;
- pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
-
- status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
- EFI_LOADER_DATA, pages, &target);
- if (status == EFI_SUCCESS)
- *addr = target;
- break;
- }
-
- efi_bs_call(free_pool, memory_map);
-
- return status;
-}
-
efi_status_t efi_random_get_seed(void)
{
efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID;
--- /dev/null
+++ b/drivers/firmware/efi/libstub/randomalloc.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016 Linaro Ltd; <ard.biesheuvel@linaro.org>
+ */
+
+#include <linux/efi.h>
+#include <linux/log2.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+/*
+ * Return the number of slots covered by this entry, i.e., the number of
+ * addresses it covers that are suitably aligned and supply enough room
+ * for the allocation.
+ */
+static unsigned long get_entry_num_slots(efi_memory_desc_t *md,
+ unsigned long size,
+ unsigned long align_shift)
+{
+ unsigned long align = 1UL << align_shift;
+ u64 first_slot, last_slot, region_end;
+
+ if (md->type != EFI_CONVENTIONAL_MEMORY)
+ return 0;
+
+ if (efi_soft_reserve_enabled() &&
+ (md->attribute & EFI_MEMORY_SP))
+ return 0;
+
+ region_end = min(md->phys_addr + md->num_pages * EFI_PAGE_SIZE - 1,
+ (u64)ULONG_MAX);
+
+ first_slot = round_up(md->phys_addr, align);
+ last_slot = round_down(region_end - size + 1, align);
+
+ if (first_slot > last_slot)
+ return 0;
+
+ return ((unsigned long)(last_slot - first_slot) >> align_shift) + 1;
+}
+
+/*
+ * The UEFI memory descriptors have a virtual address field that is only used
+ * when installing the virtual mapping using SetVirtualAddressMap(). Since it
+ * is unused here, we can reuse it to keep track of each descriptor's slot
+ * count.
+ */
+#define MD_NUM_SLOTS(md) ((md)->virt_addr)
+
+efi_status_t efi_random_alloc(unsigned long size,
+ unsigned long align,
+ unsigned long *addr,
+ unsigned long random_seed)
+{
+ unsigned long map_size, desc_size, total_slots = 0, target_slot;
+ unsigned long buff_size;
+ efi_status_t status;
+ efi_memory_desc_t *memory_map;
+ int map_offset;
+ struct efi_boot_memmap map;
+
+ map.map = &memory_map;
+ map.map_size = &map_size;
+ map.desc_size = &desc_size;
+ map.desc_ver = NULL;
+ map.key_ptr = NULL;
+ map.buff_size = &buff_size;
+
+ status = efi_get_memory_map(&map);
+ if (status != EFI_SUCCESS)
+ return status;
+
+ if (align < EFI_ALLOC_ALIGN)
+ align = EFI_ALLOC_ALIGN;
+
+ /* count the suitable slots in each memory map entry */
+ for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
+ efi_memory_desc_t *md = (void *)memory_map + map_offset;
+ unsigned long slots;
+
+ slots = get_entry_num_slots(md, size, ilog2(align));
+ MD_NUM_SLOTS(md) = slots;
+ total_slots += slots;
+ }
+
+ /* find a random number between 0 and total_slots */
+ target_slot = (total_slots * (u16)random_seed) >> 16;
+
+ /*
+ * target_slot is now a value in the range [0, total_slots), and so
+ * it corresponds with exactly one of the suitable slots we recorded
+ * when iterating over the memory map the first time around.
+ *
+ * So iterate over the memory map again, subtracting the number of
+ * slots of each entry at each iteration, until we have found the entry
+ * that covers our chosen slot. Use the residual value of target_slot
+ * to calculate the randomly chosen address, and allocate it directly
+ * using EFI_ALLOCATE_ADDRESS.
+ */
+ for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
+ efi_memory_desc_t *md = (void *)memory_map + map_offset;
+ efi_physical_addr_t target;
+ unsigned long pages;
+
+ if (target_slot >= MD_NUM_SLOTS(md)) {
+ target_slot -= MD_NUM_SLOTS(md);
+ continue;
+ }
+
+ target = round_up(md->phys_addr, align) + target_slot * align;
+ pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+
+ status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
+ EFI_LOADER_DATA, pages, &target);
+ if (status == EFI_SUCCESS)
+ *addr = target;
+ break;
+ }
+
+ efi_bs_call(free_pool, memory_map);
+
+ return status;
+}