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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /drivers/firmware/efi/libstub
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'drivers/firmware/efi/libstub')
-rw-r--r--drivers/firmware/efi/libstub/Makefile42
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c78
-rw-r--r--drivers/firmware/efi/libstub/fdt.c9
-rw-r--r--drivers/firmware/efi/libstub/string.c57
4 files changed, 171 insertions, 15 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 816dbe9f4..3c0467d36 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -14,6 +14,8 @@ cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS))
cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \
-fno-builtin -fpic -mno-single-pic-base
+cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt
+
KBUILD_CFLAGS := $(cflags-y) \
$(call cc-option,-ffreestanding) \
$(call cc-option,-fno-stack-protector)
@@ -22,7 +24,18 @@ GCOV_PROFILE := n
KASAN_SANITIZE := n
lib-y := efi-stub-helper.o
-lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o
+
+# include the stub's generic dependencies from lib/ when building for ARM/arm64
+arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c
+
+$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
+ $(call if_changed_rule,cc_o_c)
+
+lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \
+ $(patsubst %.c,lib-%.o,$(arm-deps))
+
+lib-$(CONFIG_ARM64) += arm64-stub.o
+CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
#
# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
@@ -30,10 +43,27 @@ lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o
# So let's apply the __init annotations at the section level, by prefixing
# the section names directly. This will ensure that even all the inline string
# literals are covered.
+# The fact that the stub and the kernel proper are essentially the same binary
+# also means that we need to be extra careful to make sure that the stub does
+# not rely on any absolute symbol references, considering that the virtual
+# kernel mapping that the linker uses is not active yet when the stub is
+# executing. So build all C dependencies of the EFI stub into libstub, and do
+# a verification pass to see if any absolute relocations exist in any of the
+# object files.
#
-extra-$(CONFIG_ARM64) := $(lib-y)
-lib-$(CONFIG_ARM64) := $(patsubst %.o,%.init.o,$(lib-y))
+extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y)
+lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y))
+
+STUBCOPY_FLAGS-y := -R .debug* -R *ksymtab* -R *kcrctab*
+STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \
+ --prefix-symbols=__efistub_
+STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS
+
+$(obj)/%.stub.o: $(obj)/%.o FORCE
+ $(call if_changed,stubcopy)
-OBJCOPYFLAGS := --prefix-alloc-sections=.init
-$(obj)/%.init.o: $(obj)/%.o FORCE
- $(call if_changed,objcopy)
+quiet_cmd_stubcopy = STUBCPY $@
+ cmd_stubcopy = if $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; then \
+ $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y) \
+ && (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
+ rm -f $@; /bin/false); else /bin/false; fi
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
new file mode 100644
index 000000000..78dfbd34b
--- /dev/null
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
+ *
+ * This file implements the EFI boot stub for the arm64 kernel.
+ * Adapted from ARM version by Mark Salter <msalter@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <asm/sections.h>
+
+efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
+ unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long dram_base,
+ efi_loaded_image_t *image)
+{
+ efi_status_t status;
+ unsigned long kernel_size, kernel_memsize = 0;
+ unsigned long nr_pages;
+ void *old_image_addr = (void *)*image_addr;
+ unsigned long preferred_offset;
+
+ /*
+ * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond
+ * a 2 MB aligned base, which itself may be lower than dram_base, as
+ * long as the resulting offset equals or exceeds it.
+ */
+ preferred_offset = round_down(dram_base, SZ_2M) + TEXT_OFFSET;
+ if (preferred_offset < dram_base)
+ preferred_offset += SZ_2M;
+
+ /* Relocate the image, if required. */
+ kernel_size = _edata - _text;
+ if (*image_addr != preferred_offset) {
+ kernel_memsize = kernel_size + (_end - _edata);
+
+ /*
+ * First, try a straight allocation at the preferred offset.
+ * This will work around the issue where, if dram_base == 0x0,
+ * efi_low_alloc() refuses to allocate at 0x0 (to prevent the
+ * address of the allocation to be mistaken for a FAIL return
+ * value or a NULL pointer). It will also ensure that, on
+ * platforms where the [dram_base, dram_base + TEXT_OFFSET)
+ * interval is partially occupied by the firmware (like on APM
+ * Mustang), we can still place the kernel at the address
+ * 'dram_base + TEXT_OFFSET'.
+ */
+ *image_addr = *reserve_addr = preferred_offset;
+ nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
+ EFI_PAGE_SIZE;
+ status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
+ EFI_LOADER_DATA, nr_pages,
+ (efi_physical_addr_t *)reserve_addr);
+ if (status != EFI_SUCCESS) {
+ kernel_memsize += TEXT_OFFSET;
+ status = efi_low_alloc(sys_table_arg, kernel_memsize,
+ SZ_2M, reserve_addr);
+
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
+ return status;
+ }
+ *image_addr = *reserve_addr + TEXT_OFFSET;
+ }
+ memcpy((void *)*image_addr, old_image_addr, kernel_size);
+ *reserve_size = kernel_memsize;
+ }
+
+
+ return EFI_SUCCESS;
+}
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index ef5d764e2..b62e2f5dc 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -147,15 +147,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
if (status)
goto fdt_set_fail;
- /*
- * Add kernel version banner so stub/kernel match can be
- * verified.
- */
- status = fdt_setprop_string(fdt, node, "linux,uefi-stub-kern-ver",
- linux_banner);
- if (status)
- goto fdt_set_fail;
-
return EFI_SUCCESS;
fdt_set_fail:
diff --git a/drivers/firmware/efi/libstub/string.c b/drivers/firmware/efi/libstub/string.c
new file mode 100644
index 000000000..09d5a0894
--- /dev/null
+++ b/drivers/firmware/efi/libstub/string.c
@@ -0,0 +1,57 @@
+/*
+ * Taken from:
+ * linux/lib/string.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+
+#ifndef __HAVE_ARCH_STRSTR
+/**
+ * strstr - Find the first substring in a %NUL terminated string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ */
+char *strstr(const char *s1, const char *s2)
+{
+ size_t l1, l2;
+
+ l2 = strlen(s2);
+ if (!l2)
+ return (char *)s1;
+ l1 = strlen(s1);
+ while (l1 >= l2) {
+ l1--;
+ if (!memcmp(s1, s2, l2))
+ return (char *)s1;
+ s1++;
+ }
+ return NULL;
+}
+#endif
+
+#ifndef __HAVE_ARCH_STRNCMP
+/**
+ * strncmp - Compare two length-limited strings
+ * @cs: One string
+ * @ct: Another string
+ * @count: The maximum number of bytes to compare
+ */
+int strncmp(const char *cs, const char *ct, size_t count)
+{
+ unsigned char c1, c2;
+
+ while (count) {
+ c1 = *cs++;
+ c2 = *ct++;
+ if (c1 != c2)
+ return c1 < c2 ? -1 : 1;
+ if (!c1)
+ break;
+ count--;
+ }
+ return 0;
+}
+#endif