From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>,
nivedita@alum.mit.edu, mingo@kernel.org, lukas@wunner.de,
atish.patra@wdc.com
Subject: [PATCH 12/19] efi/libstub: Move efi_random_alloc() into separate source file
Date: Mon, 10 Feb 2020 17:02:41 +0100 [thread overview]
Message-ID: <20200210160248.4889-13-ardb@kernel.org> (raw)
In-Reply-To: <20200210160248.4889-1-ardb@kernel.org>
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>
---
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(-)
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 8e15634fa929..ac0d0e1ef32d 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -39,7 +39,7 @@ 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
diff --git a/drivers/firmware/efi/libstub/random.c b/drivers/firmware/efi/libstub/random.c
index 316ce9ff0193..21e7e9325219 100644
--- 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(unsigned long size, u8 *out)
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;
diff --git a/drivers/firmware/efi/libstub/randomalloc.c b/drivers/firmware/efi/libstub/randomalloc.c
new file mode 100644
index 000000000000..4578f59e160c
--- /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;
+}
--
2.17.1
next prev parent reply other threads:[~2020-02-10 16:03 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-10 16:02 [PATCH 00/19] EFI stub early spring cleaning part 2 Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 01/19] efi/libstub/x86: Remove pointless zeroing of apm_bios_info Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 02/19] efi/libstub/x86: Avoid overflowing code32_start on PE entry Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 03/19] efi/libstub: Use hidden visiblity for all source files Ard Biesheuvel
2020-02-24 23:15 ` Atish Patra
2020-02-24 23:36 ` Ard Biesheuvel
2020-02-25 19:18 ` Atish Patra
2020-02-10 16:02 ` [PATCH 04/19] efi/libstub/arm: Relax FDT alignment requirement Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 05/19] efi/libstub: Move memory map handling and allocation routines to mem.c Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 06/19] efi/libstub: Simplify efi_high_alloc() and rename to efi_allocate_pages() Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 07/19] efi/libstub/x86: Incorporate eboot.c into libstub Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 08/19] efi/libstub: Use consistent type names for file I/O protocols Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 09/19] efi/libstub: Move stub specific declarations into efistub.h Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 10/19] efi/libstub/x86: Permit bootparams struct to be allocated above 4 GB Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 11/19] efi/libstub/x86: Permit cmdline data " Ard Biesheuvel
2020-02-10 16:02 ` Ard Biesheuvel [this message]
2020-02-10 16:02 ` [PATCH 13/19] efi/libstub: Move get_dram_base() into arm-stub.c Ard Biesheuvel
2020-02-17 1:17 ` Atish Patra
2020-02-17 8:37 ` Ard Biesheuvel
2020-02-26 23:34 ` Atish Patra
2020-02-27 7:38 ` Ard Biesheuvel
2020-02-27 7:48 ` Atish Patra
2020-02-27 7:50 ` Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 14/19] efi/libstub: Move file I/O support code into separate file Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 15/19] efi/libstub: Rewrite file I/O routine Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 16/19] efi/libstub: Take soft and hard memory limits into account for initrd loading Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 17/19] efi/libstub: Clean up command line parsing routine Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 18/19] efi/libstub: Expose LocateDevicePath boot service Ard Biesheuvel
2020-02-10 16:02 ` [PATCH 19/19] efi/libstub: Make the LoadFile EFI protocol accessible Ard Biesheuvel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200210160248.4889-13-ardb@kernel.org \
--to=ardb@kernel.org \
--cc=atish.patra@wdc.com \
--cc=linux-efi@vger.kernel.org \
--cc=lukas@wunner.de \
--cc=mingo@kernel.org \
--cc=nivedita@alum.mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.