From aab9593c0cb4454f9d261a8c87a3361f3186c4ec Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 20 Jul 2018 10:47:24 +0900 Subject: [PATCH] efi/x86: Replace references to efi_early->is64 with efi_is_64bit() There are a couple of places in the x86 EFI stub code where we select between 32-bit and 64-bit versions of the support routines based on the value of efi_early->is64. Referencing that field directly is a bad idea, since it prevents the compiler from inferring that this field can never be true on a 32-bit build, and can only become false on a 64-bit build if support for mixed mode is compiled in. This results in dead code to be retained in the uncompressed part of the kernel image, which is wasteful. So switch to the efi_is_64bit() helper, which will resolve to a constant boolean unless building for 64-bit with mixed mode support. Tested-by: Hans de Goede Signed-off-by: Ard Biesheuvel Cc: Andy Shevchenko Cc: Linus Torvalds Cc: Lukas Wunner Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-8-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- arch/x86/boot/compressed/eboot.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index 915c64edbe8e..1458b1700fc7 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -404,7 +404,7 @@ struct boot_params *make_boot_params(struct efi_config *c) if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) return NULL; - if (efi_early->is64) + if (efi_is_64bit()) setup_boot_services64(efi_early); else setup_boot_services32(efi_early); @@ -639,7 +639,6 @@ struct exit_boot_struct { struct efi_info *efi; struct setup_data *e820ext; __u32 e820ext_size; - bool is64; }; static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, @@ -666,7 +665,8 @@ static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, first = false; } - signature = p->is64 ? EFI64_LOADER_SIGNATURE : EFI32_LOADER_SIGNATURE; + signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE + : EFI32_LOADER_SIGNATURE; memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); p->efi->efi_systab = (unsigned long)sys_table_arg; @@ -683,8 +683,7 @@ static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, return EFI_SUCCESS; } -static efi_status_t exit_boot(struct boot_params *boot_params, - void *handle, bool is64) +static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) { unsigned long map_sz, key, desc_size, buff_size; efi_memory_desc_t *mem_map; @@ -705,7 +704,6 @@ static efi_status_t exit_boot(struct boot_params *boot_params, priv.efi = &boot_params->efi_info; priv.e820ext = NULL; priv.e820ext_size = 0; - priv.is64 = is64; /* Might as well exit boot services now */ status = efi_exit_boot_services(sys_table, handle, &map, &priv, @@ -740,13 +738,11 @@ efi_main(struct efi_config *c, struct boot_params *boot_params) struct desc_struct *desc; void *handle; efi_system_table_t *_table; - bool is64; efi_early = c; _table = (efi_system_table_t *)(unsigned long)efi_early->table; handle = (void *)(unsigned long)efi_early->image_handle; - is64 = efi_early->is64; sys_table = _table; @@ -754,7 +750,7 @@ efi_main(struct efi_config *c, struct boot_params *boot_params) if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) goto fail; - if (is64) + if (efi_is_64bit()) setup_boot_services64(efi_early); else setup_boot_services32(efi_early); @@ -810,7 +806,7 @@ efi_main(struct efi_config *c, struct boot_params *boot_params) hdr->code32_start = bzimage_addr; } - status = exit_boot(boot_params, handle, is64); + status = exit_boot(boot_params, handle); if (status != EFI_SUCCESS) { efi_printk(sys_table, "exit_boot() failed!\n"); goto fail; -- GitLab