Re: [GIT PULL] x86 fixes

[Matt Fleming <matt@console-pimps.org>]

On Tue, 23 Sep, at 10:18:07AM, Ard Biesheuvel wrote:
> 
> It will be difficult for me to keep up with this thread over the next
> days, so I have added Leif and Roy on cc. If you need to make any
> changes that affect arm64, they should be able to confirm whether it
> causes any problems or not.

OK, below is what I've got on top of commit f3670394c29f in Linus' tree.
Please don't anyone pick this up yet, I'm still testing it on my
machines and it desperately needs some Tested-by tags.

Josh, your machines probably boot fine after the revert from Linus but
it'd be good to verify that this patch doesn't make things any worse.

Maarten, please verify that your Macbook pro boots with this patch. I
very much want to be able to add a Tested-by from you.

Ard, Leif, Roy, can you please validate this for arm64? The thing to
look out for is whether the changes to drivers/firmware/efi/Makefile
make sense, and in particular, whether it's ever possible to have
CONFIG_EFI_STUB=y and CONFIG_EFI_ARM_STUB=n.

If the answer is yes, then this patch might break your build and we
probably want to do something like unconditionally select
CONFIG_EFI_ARM_STUB when CONFIG_EFI_STUB=y.

---

>From 8054c405f0acc8ecb74b7e29675a1e6894afedb0 Mon Sep 17 00:00:00 2001
From: Matt Fleming <matt.fleming@intel.com>
Date: Tue, 23 Sep 2014 10:37:43 +0100
Subject: [PATCH] Revert "efi/x86: efistub: Move shared dependencies to
 <asm/efi.h>"

This reverts commit f23cf8bd5c1f ("efi/x86: efistub: Move shared
dependencies to <asm/efi.h>") as well as the x86 parts of commit
f4f75ad5741f ("efi: efistub: Convert into static library").

The road leading to these two reverts is long and winding.

The above two commits were merged during the v3.17 merge window and
turned the common EFI boot stub code into a static library. This
necessitated making some symbols global in the x86 boot stub which
introduced new entries into the early boot GOT.

The problem was that we weren't fixing up the newly created GOT entries
before invoking the EFI boot stub, which sometimes resulted in hangs or
resets. This failure was reported by Maarten on his Macbook pro.

The proposed fix was commit 9cb0e394234d ("x86/efi: Fixup GOT in all
boot code paths"). However, that caused issues for Linus when booting
his Sony Vaio Pro 11. It was subsequently reverted in commit
f3670394c29f.

So that leaves us back with Maarten's Macbook pro not booting.

At this stage in the release cycle the least risky option is to revert
the x86 EFI boot stub to the pre-merge window code structure where we
explicitly #include efi-stub-helper.c instead of linking with the static
library. The arm64 code remains unaffected.

We can take another swing at the x86 parts for v3.18.

Conflicts:
	arch/x86/include/asm/efi.h

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---
 arch/x86/boot/compressed/Makefile |  3 +--
 arch/x86/boot/compressed/eboot.c  |  7 ++++++-
 arch/x86/boot/compressed/eboot.h  | 16 ++++++++++++++++
 arch/x86/include/asm/efi.h        | 24 ------------------------
 drivers/firmware/efi/Makefile     |  2 +-
 5 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 7a801a310e37..0fcd9133790c 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -33,8 +33,7 @@ VMLINUX_OBJS = $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
 $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
 
 ifeq ($(CONFIG_EFI_STUB), y)
-	VMLINUX_OBJS += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
-				$(objtree)/drivers/firmware/efi/libstub/lib.a
+	VMLINUX_OBJS += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o
 endif
 
 $(obj)/vmlinux: $(VMLINUX_OBJS) FORCE
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index dca9842d8f91..b04f1e0e3fab 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -19,7 +19,10 @@
 
 static efi_system_table_t *sys_table;
 
-struct efi_config *efi_early;
+static struct efi_config *efi_early;
+
+#define efi_call_early(f, ...)						\
+	efi_early->call(efi_early->f, __VA_ARGS__);
 
 #define BOOT_SERVICES(bits)						\
 static void setup_boot_services##bits(struct efi_config *c)		\
@@ -280,6 +283,8 @@ void efi_char16_printk(efi_system_table_t *table, efi_char16_t *str)
 	}
 }
 
+#include "../../../../drivers/firmware/efi/libstub/efi-stub-helper.c"
+
 static void find_bits(unsigned long mask, u8 *pos, u8 *size)
 {
 	u8 first, len;
diff --git a/arch/x86/boot/compressed/eboot.h b/arch/x86/boot/compressed/eboot.h
index d487e727f1ec..c88c31ecad12 100644
--- a/arch/x86/boot/compressed/eboot.h
+++ b/arch/x86/boot/compressed/eboot.h
@@ -103,4 +103,20 @@ struct efi_uga_draw_protocol {
 	void *blt;
 };
 
+struct efi_config {
+	u64 image_handle;
+	u64 table;
+	u64 allocate_pool;
+	u64 allocate_pages;
+	u64 get_memory_map;
+	u64 free_pool;
+	u64 free_pages;
+	u64 locate_handle;
+	u64 handle_protocol;
+	u64 exit_boot_services;
+	u64 text_output;
+	efi_status_t (*call)(unsigned long, ...);
+	bool is64;
+} __packed;
+
 #endif /* BOOT_COMPRESSED_EBOOT_H */
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 044a2fd3c5fe..0ec241ede5a2 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -159,30 +159,6 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
 }
 #endif /* CONFIG_EFI_MIXED */
 
-
-/* arch specific definitions used by the stub code */
-
-struct efi_config {
-	u64 image_handle;
-	u64 table;
-	u64 allocate_pool;
-	u64 allocate_pages;
-	u64 get_memory_map;
-	u64 free_pool;
-	u64 free_pages;
-	u64 locate_handle;
-	u64 handle_protocol;
-	u64 exit_boot_services;
-	u64 text_output;
-	efi_status_t (*call)(unsigned long, ...);
-	bool is64;
-} __packed;
-
-extern struct efi_config *efi_early;
-
-#define efi_call_early(f, ...)						\
-	efi_early->call(efi_early->f, __VA_ARGS__);
-
 extern bool efi_reboot_required(void);
 
 #else
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index d8be608a9f3b..aef6a95adef5 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -7,4 +7,4 @@ obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o
 obj-$(CONFIG_UEFI_CPER)			+= cper.o
 obj-$(CONFIG_EFI_RUNTIME_MAP)		+= runtime-map.o
 obj-$(CONFIG_EFI_RUNTIME_WRAPPERS)	+= runtime-wrappers.o
-obj-$(CONFIG_EFI_STUB)			+= libstub/
+obj-$(CONFIG_EFI_ARM_STUB)		+= libstub/
-- 
1.9.3

-- 
Matt Fleming, Intel Open Source Technology Center