From 243b6754cd17112bbf0724ed3c13446b48cf6a28 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 5 Nov 2014 17:00:56 +0100 Subject: [PATCH] efi/x86: Move x86 back to libstub This reverts commit 84be880560fb, which itself reverted my original attempt to move x86 from #include'ing .c files from across the tree to using the EFI stub built as a static library. The issue that affected the original approach was that splitting the implementation into several .o files resulted in the variable 'efi_early' becoming a global with external linkage, which under -fPIC implies that references to it must go through the GOT. However, dealing with this additional GOT entry turned out to be troublesome on some EFI implementations. (GCC's visibility=hidden attribute is supposed to lift this requirement, but it turned out not to work on the 32-bit build.) Instead, use a pure getter function to get a reference to efi_early. This approach results in no additional GOT entries being generated, so there is no need for any changes in the early GOT handling. Tested-by: Maarten Lankhorst Signed-off-by: Ard Biesheuvel Signed-off-by: Matt Fleming --- arch/x86/boot/compressed/Makefile | 3 ++- arch/x86/boot/compressed/eboot.c | 8 ++++---- arch/x86/boot/compressed/eboot.h | 16 ---------------- arch/x86/include/asm/efi.h | 24 ++++++++++++++++++++++++ drivers/firmware/efi/Makefile | 2 +- 5 files changed, 31 insertions(+), 22 deletions(-) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 704f58aa79cd..20db5b3609de 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -35,7 +35,8 @@ vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/aslr.o $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone -vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o +vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \ + $(objtree)/drivers/firmware/efi/libstub/lib.a $(obj)/vmlinux: $(vmlinux-objs-y) FORCE $(call if_changed,ld) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index 1acf605a646d..92b9a5f2aed6 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -21,8 +21,10 @@ static efi_system_table_t *sys_table; static struct efi_config *efi_early; -#define efi_call_early(f, ...) \ - efi_early->call(efi_early->f, __VA_ARGS__); +__pure const struct efi_config *__efi_early(void) +{ + return efi_early; +} #define BOOT_SERVICES(bits) \ static void setup_boot_services##bits(struct efi_config *c) \ @@ -285,8 +287,6 @@ 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 c88c31ecad12..d487e727f1ec 100644 --- a/arch/x86/boot/compressed/eboot.h +++ b/arch/x86/boot/compressed/eboot.h @@ -103,20 +103,4 @@ 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 9b11757975d0..25bce45c6fc4 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -158,6 +158,30 @@ 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; + +__pure const struct efi_config *__efi_early(void); + +#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 aef6a95adef5..d8be608a9f3b 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_ARM_STUB) += libstub/ +obj-$(CONFIG_EFI_STUB) += libstub/ -- GitLab