[GIT PULL] EFI fixes

From: Ingo Molnar
Date: Sat Jul 25 2020 - 06:33:10 EST


Linus,

Please pull the latest efi/urgent git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git efi-urgent-2020-07-25

# HEAD: 74f85551666fe40bd739e95b5ecb20f53f8ad4df Merge tag 'efi-urgent-for-v5.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/urgent

Various EFI fixes:

- Fix the layering violation in the use of the EFI runtime services
availability mask in users of the 'efivars' abstraction

- Revert build fix for GCC v4.8 which is no longer supported

- Clean up some x86 EFI stub details, some of which are borderline bugs
that copy around garbage into padding fields - let's fix these
out of caution.

- Fix build issues while working on RISC-V support

- Avoid --whole-archive when linking the stub on arm64

Thanks,

Ingo

------------------>
Ard Biesheuvel (2):
efi/efivars: Expose RT service availability via efivars abstraction
efi: Revert "efi/x86: Fix build with gcc 4"

Arvind Sankar (2):
efi/x86: Remove unused variables
efi/x86: Only copy upto the end of setup_header

Atish Patra (2):
efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds
efi/libstub: Move the function prototypes to header file

Masahiro Yamada (1):
efi/libstub/arm64: link stub lib.a conditionally


arch/arm64/Makefile | 2 +-
drivers/firmware/efi/efi-pstore.c | 5 +----
drivers/firmware/efi/efi.c | 12 ++++++++----
drivers/firmware/efi/efivars.c | 5 +----
drivers/firmware/efi/libstub/Makefile | 3 +--
drivers/firmware/efi/libstub/alignedmem.c | 2 +-
drivers/firmware/efi/libstub/efi-stub.c | 17 -----------------
drivers/firmware/efi/libstub/efistub.h | 16 ++++++++++++++++
drivers/firmware/efi/libstub/x86-stub.c | 8 ++++----
drivers/firmware/efi/vars.c | 6 ++++++
fs/efivarfs/super.c | 6 +++---
include/linux/efi.h | 1 +
12 files changed, 43 insertions(+), 40 deletions(-)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 76359cfb328a..4621fb690d9c 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -143,7 +143,7 @@ export TEXT_OFFSET

core-y += arch/arm64/
libs-y := arch/arm64/lib/ $(libs-y)
-core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
+libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a

# Default target when executing plain make
boot := arch/arm64/boot
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index c2f1d4e6630b..feb7fe6f2da7 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -356,10 +356,7 @@ static struct pstore_info efi_pstore_info = {

static __init int efivars_pstore_init(void)
{
- if (!efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
- return 0;
-
- if (!efivars_kobject())
+ if (!efivars_kobject() || !efivar_supports_writes())
return 0;

if (efivars_pstore_disable)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 5114cae4ec97..fdd1db025dbf 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -176,11 +176,13 @@ static struct efivar_operations generic_ops;
static int generic_ops_register(void)
{
generic_ops.get_variable = efi.get_variable;
- generic_ops.set_variable = efi.set_variable;
- generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
generic_ops.get_next_variable = efi.get_next_variable;
generic_ops.query_variable_store = efi_query_variable_store;

+ if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
+ generic_ops.set_variable = efi.set_variable;
+ generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
+ }
return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
}

@@ -382,7 +384,8 @@ static int __init efisubsys_init(void)
return -ENOMEM;
}

- if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES)) {
+ if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
+ EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
efivar_ssdt_load();
error = generic_ops_register();
if (error)
@@ -416,7 +419,8 @@ static int __init efisubsys_init(void)
err_remove_group:
sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
err_unregister:
- if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
+ if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
+ EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
generic_ops_unregister();
err_put:
kobject_put(efi_kobj);
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 26528a46d99e..dcea137142b3 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -680,11 +680,8 @@ int efivars_sysfs_init(void)
struct kobject *parent_kobj = efivars_kobject();
int error = 0;

- if (!efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
- return -ENODEV;
-
/* No efivars has been registered yet */
- if (!parent_kobj)
+ if (!parent_kobj || !efivar_supports_writes())
return 0;

printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 4cce372edaf4..75daaf20374e 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -6,8 +6,7 @@
# enabled, even if doing so doesn't break the build.
#
cflags-$(CONFIG_X86_32) := -march=i386
-cflags-$(CONFIG_X86_64) := -mcmodel=small \
- $(call cc-option,-maccumulate-outgoing-args)
+cflags-$(CONFIG_X86_64) := -mcmodel=small
cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \
-fPIC -fno-strict-aliasing -mno-red-zone \
-mno-mmx -mno-sse -fshort-wchar \
diff --git a/drivers/firmware/efi/libstub/alignedmem.c b/drivers/firmware/efi/libstub/alignedmem.c
index cc89c4d6196f..1de9878ddd3a 100644
--- a/drivers/firmware/efi/libstub/alignedmem.c
+++ b/drivers/firmware/efi/libstub/alignedmem.c
@@ -44,7 +44,7 @@ efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr,
*addr = ALIGN((unsigned long)alloc_addr, align);

if (slack > 0) {
- int l = (alloc_addr % align) / EFI_PAGE_SIZE;
+ int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE;

if (l) {
efi_bs_call(free_pages, alloc_addr, slack - l + 1);
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 3318ec3f8e5b..a5a405d8ab44 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -121,23 +121,6 @@ static unsigned long get_dram_base(void)
return membase;
}

-/*
- * This function handles the architcture specific differences between arm and
- * arm64 regarding where the kernel image must be loaded and any memory that
- * must be reserved. On failure it is required to free all
- * all allocations it has made.
- */
-efi_status_t handle_kernel_image(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);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
- unsigned long fdt_addr,
- unsigned long fdt_size);
-
/*
* EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
* that is described in the PE/COFF header. Most of the code is the same
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 2c9d42264c29..85050f5a1b28 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -776,6 +776,22 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image,
unsigned long *load_size,
unsigned long soft_limit,
unsigned long hard_limit);
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+efi_status_t handle_kernel_image(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);
+
+asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
+ unsigned long fdt_addr,
+ unsigned long fdt_size);

void efi_handle_post_ebs_state(void);

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 5a48d996ed71..3672539cb96e 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -8,6 +8,7 @@

#include <linux/efi.h>
#include <linux/pci.h>
+#include <linux/stddef.h>

#include <asm/efi.h>
#include <asm/e820/types.h>
@@ -361,8 +362,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
int options_size = 0;
efi_status_t status;
char *cmdline_ptr;
- unsigned long ramdisk_addr;
- unsigned long ramdisk_size;

efi_system_table = sys_table_arg;

@@ -390,8 +389,9 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,

hdr = &boot_params->hdr;

- /* Copy the second sector to boot_params */
- memcpy(&hdr->jump, image_base + 512, 512);
+ /* Copy the setup header from the second sector to boot_params */
+ memcpy(&hdr->jump, image_base + 512,
+ sizeof(struct setup_header) - offsetof(struct setup_header, jump));

/*
* Fill out some of the header fields ourselves because the
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 5f2a4d162795..973eef234b36 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -1229,3 +1229,9 @@ int efivars_unregister(struct efivars *efivars)
return rv;
}
EXPORT_SYMBOL_GPL(efivars_unregister);
+
+int efivar_supports_writes(void)
+{
+ return __efivars && __efivars->ops->set_variable;
+}
+EXPORT_SYMBOL_GPL(efivar_supports_writes);
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index 12c66f5d92dd..28bb5689333a 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -201,6 +201,9 @@ static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_d_op = &efivarfs_d_ops;
sb->s_time_gran = 1;

+ if (!efivar_supports_writes())
+ sb->s_flags |= SB_RDONLY;
+
inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0, true);
if (!inode)
return -ENOMEM;
@@ -252,9 +255,6 @@ static struct file_system_type efivarfs_type = {

static __init int efivarfs_init(void)
{
- if (!efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
- return -ENODEV;
-
if (!efivars_kobject())
return -ENODEV;

diff --git a/include/linux/efi.h b/include/linux/efi.h
index bb35f3305e55..05c47f857383 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -994,6 +994,7 @@ int efivars_register(struct efivars *efivars,
int efivars_unregister(struct efivars *efivars);
struct kobject *efivars_kobject(void);

+int efivar_supports_writes(void);
int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
void *data, bool duplicates, struct list_head *head);