efi/libstub/x86: Drop __efi_early() export and efi_config struct
authorArd Biesheuvel <ardb@kernel.org>
Tue, 24 Dec 2019 15:10:17 +0000 (16:10 +0100)
committerIngo Molnar <mingo@kernel.org>
Wed, 25 Dec 2019 09:49:22 +0000 (10:49 +0100)
The various pointers we stash in the efi_config struct which we
retrieve using __efi_early() are simply copies of the ones in
the EFI system table, which we have started accessing directly
in the previous patch. So drop all the __efi_early() related
plumbing, as well as all the assembly code dealing with efi_config,
which allows us to move the PE/COFF entry point to C code as well.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-18-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/boot/compressed/eboot.c
arch/x86/boot/compressed/head_32.S
arch/x86/boot/compressed/head_64.S
arch/x86/include/asm/efi.h

index 5fb1282..2a7c6d5 100644 (file)
 #include "eboot.h"
 
 static efi_system_table_t *sys_table;
-
-static struct efi_config *efi_early;
-
-__pure const struct efi_config *__efi_early(void)
-{
-       return efi_early;
-}
+static bool efi_is64 = IS_ENABLED(CONFIG_X86_64);
 
 __pure efi_system_table_t *efi_system_table(void)
 {
        return sys_table;
 }
 
-#define BOOT_SERVICES(bits)                                            \
-static void setup_boot_services##bits(struct efi_config *c)            \
-{                                                                      \
-       efi_system_table_##bits##_t *table;                             \
-                                                                       \
-       table = (typeof(table))sys_table;                               \
-                                                                       \
-       c->runtime_services     = table->runtime;                       \
-       c->boot_services        = table->boottime;                      \
-       c->text_output          = table->con_out;                       \
+__pure bool efi_is_64bit(void)
+{
+       return efi_is64;
 }
-BOOT_SERVICES(32);
-BOOT_SERVICES(64);
 
 static efi_status_t
 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
@@ -367,21 +352,24 @@ void setup_graphics(struct boot_params *boot_params)
        }
 }
 
+void startup_32(struct boot_params *boot_params);
+
+void __noreturn efi_stub_entry(efi_handle_t handle,
+                              efi_system_table_t *sys_table_arg,
+                              struct boot_params *boot_params);
+
 /*
  * Because the x86 boot code expects to be passed a boot_params we
  * need to create one ourselves (usually the bootloader would create
  * one for us).
- *
- * The caller is responsible for filling out ->code32_start in the
- * returned boot_params.
  */
-struct boot_params *make_boot_params(struct efi_config *c)
+efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
+                                  efi_system_table_t *sys_table_arg)
 {
        struct boot_params *boot_params;
        struct apm_bios_info *bi;
        struct setup_header *hdr;
        efi_loaded_image_t *image;
-       void *handle;
        efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
        int options_size = 0;
        efi_status_t status;
@@ -389,31 +377,24 @@ struct boot_params *make_boot_params(struct efi_config *c)
        unsigned long ramdisk_addr;
        unsigned long ramdisk_size;
 
-       efi_early = c;
-       sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;
-       handle = (void *)(unsigned long)efi_early->image_handle;
+       sys_table = sys_table_arg;
 
        /* Check if we were booted by the EFI firmware */
        if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
-               return NULL;
-
-       if (efi_is_64bit())
-               setup_boot_services64(efi_early);
-       else
-               setup_boot_services32(efi_early);
+               return EFI_INVALID_PARAMETER;
 
        status = efi_call_early(handle_protocol, handle,
                                &proto, (void *)&image);
        if (status != EFI_SUCCESS) {
                efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
-               return NULL;
+               return status;
        }
 
        status = efi_low_alloc(sys_table, 0x4000, 1,
                               (unsigned long *)&boot_params);
        if (status != EFI_SUCCESS) {
                efi_printk(sys_table, "Failed to allocate lowmem for boot params\n");
-               return NULL;
+               return status;
        }
 
        memset(boot_params, 0x0, 0x4000);
@@ -474,14 +455,17 @@ struct boot_params *make_boot_params(struct efi_config *c)
        boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
        boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
 
-       return boot_params;
+       hdr->code32_start = (u32)(unsigned long)startup_32;
+
+       efi_stub_entry(handle, sys_table, boot_params);
+       /* not reached */
 
 fail2:
        efi_free(sys_table, options_size, hdr->cmd_line_ptr);
 fail:
        efi_free(sys_table, 0x4000, (unsigned long)boot_params);
 
-       return NULL;
+       return status;
 }
 
 static void add_e820ext(struct boot_params *params,
@@ -737,33 +721,26 @@ static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
  * On success we return a pointer to a boot_params structure, and NULL
  * on failure.
  */
-struct boot_params *
-efi_main(struct efi_config *c, struct boot_params *boot_params)
+struct boot_params *efi_main(efi_handle_t handle,
+                            efi_system_table_t *sys_table_arg,
+                            struct boot_params *boot_params,
+                            bool is64)
 {
        struct desc_ptr *gdt = NULL;
        struct setup_header *hdr = &boot_params->hdr;
        efi_status_t status;
        struct desc_struct *desc;
-       void *handle;
-       efi_system_table_t *_table;
        unsigned long cmdline_paddr;
 
-       efi_early = c;
-
-       _table = (efi_system_table_t *)(unsigned long)efi_early->table;
-       handle = (void *)(unsigned long)efi_early->image_handle;
+       sys_table = sys_table_arg;
 
-       sys_table = _table;
+       if (IS_ENABLED(CONFIG_EFI_MIXED))
+               efi_is64 = is64;
 
        /* Check if we were booted by the EFI firmware */
        if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
                goto fail;
 
-       if (efi_is_64bit())
-               setup_boot_services64(efi_early);
-       else
-               setup_boot_services32(efi_early);
-
        /*
         * make_boot_params() may have been called before efi_main(), in which
         * case this is the second time we parse the cmdline. This is ok,
@@ -925,5 +902,6 @@ efi_main(struct efi_config *c, struct boot_params *boot_params)
 fail:
        efi_printk(sys_table, "efi_main() failed!\n");
 
-       return NULL;
+       for (;;)
+               asm("hlt");
 }
index 0b03dc7..e43ac17 100644 (file)
@@ -145,63 +145,16 @@ SYM_FUNC_START(startup_32)
 SYM_FUNC_END(startup_32)
 
 #ifdef CONFIG_EFI_STUB
-/*
- * We don't need the return address, so set up the stack so efi_main() can find
- * its arguments.
- */
-SYM_FUNC_START(efi_pe_entry)
-       add     $0x4, %esp
-
-       call    1f
-1:     popl    %esi
-       subl    $1b, %esi
-
-       popl    %ecx
-       movl    %ecx, efi32_config(%esi)        /* Handle */
-       popl    %ecx
-       movl    %ecx, efi32_config+8(%esi)      /* EFI System table pointer */
-
-       leal    efi32_config(%esi), %eax
-       pushl   %eax
-
-       call    make_boot_params
-       cmpl    $0, %eax
-       je      fail
-       movl    %esi, BP_code32_start(%eax)
-       popl    %ecx
-       pushl   %eax
-       pushl   %ecx
-       jmp     2f              /* Skip efi_config initialization */
-SYM_FUNC_END(efi_pe_entry)
-
 SYM_FUNC_START(efi32_stub_entry)
+SYM_FUNC_START_ALIAS(efi_stub_entry)
        add     $0x4, %esp
-       popl    %ecx
-       popl    %edx
-
-       call    1f
-1:     popl    %esi
-       subl    $1b, %esi
-
-       movl    %ecx, efi32_config(%esi)        /* Handle */
-       movl    %edx, efi32_config+8(%esi)      /* EFI System table pointer */
-
-       leal    efi32_config(%esi), %eax
-       pushl   %eax
-2:
        call    efi_main
-       cmpl    $0, %eax
        movl    %eax, %esi
-       jne     2f
-fail:
-       /* EFI init failed, so hang. */
-       hlt
-       jmp     fail
-2:
        movl    BP_code32_start(%esi), %eax
        leal    startup_32(%eax), %eax
        jmp     *%eax
 SYM_FUNC_END(efi32_stub_entry)
+SYM_FUNC_END_ALIAS(efi_stub_entry)
 #endif
 
        .text
@@ -258,13 +211,6 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
        jmp     *%eax
 SYM_FUNC_END(.Lrelocated)
 
-#ifdef CONFIG_EFI_STUB
-       .data
-efi32_config:
-       .fill 5,8,0
-       .byte 0
-#endif
-
 /*
  * Stack and heap for uncompression
  */
index ad57ede..a6f3ee9 100644 (file)
@@ -208,10 +208,14 @@ SYM_FUNC_START(startup_32)
        pushl   $__KERNEL_CS
        leal    startup_64(%ebp), %eax
 #ifdef CONFIG_EFI_MIXED
-       movl    efi32_config(%ebp), %ebx
+       movl    efi32_boot_args(%ebp), %ebx
        cmp     $0, %ebx
        jz      1f
        leal    handover_entry(%ebp), %eax
+       movl    0(%ebx), %edi
+       movl    4(%ebx), %esi
+       movl    8(%ebx), %edx
+       movl    $0x0, %ecx
 1:
 #endif
        pushl   %eax
@@ -228,22 +232,14 @@ SYM_FUNC_END(startup_32)
        .org 0x190
 SYM_FUNC_START(efi32_stub_entry)
        add     $0x4, %esp              /* Discard return address */
-       popl    %ecx
-       popl    %edx
-       popl    %esi
 
-       leal    (BP_scratch+4)(%esi), %esp
        call    1f
 1:     pop     %ebp
        subl    $1b, %ebp
 
-       movl    %ecx, efi32_config(%ebp)
-       movl    %edx, efi32_config+8(%ebp)
+       movl    %esp, efi32_boot_args(%ebp)
        sgdtl   efi32_boot_gdt(%ebp)
 
-       leal    efi32_config(%ebp), %eax
-       movl    %eax, efi_config(%ebp)
-
        /* Disable paging */
        movl    %cr0, %eax
        btrl    $X86_CR0_PG_BIT, %eax
@@ -450,51 +446,19 @@ trampoline_return:
 SYM_CODE_END(startup_64)
 
 #ifdef CONFIG_EFI_STUB
-
-/* The entry point for the PE/COFF executable is efi_pe_entry. */
-SYM_FUNC_START(efi_pe_entry)
-       movq    %rcx, efi64_config(%rip)        /* Handle */
-       movq    %rdx, efi64_config+8(%rip) /* EFI System table pointer */
-
-       leaq    efi64_config(%rip), %rax
-       movq    %rax, efi_config(%rip)
-
-       movq    %rax, %rdi
-       call    make_boot_params
-       cmpq    $0,%rax
-       je      fail
-       mov     %rax, %rsi
-       leaq    startup_32(%rip), %rax
-       movl    %eax, BP_code32_start(%rsi)
-
-handover_entry:
-       movq    efi_config(%rip), %rdi
+       .org 0x390
+SYM_FUNC_START(efi64_stub_entry)
+SYM_FUNC_START_ALIAS(efi_stub_entry)
+       movq    $1, %rcx
+SYM_INNER_LABEL(handover_entry, SYM_L_LOCAL)
        and     $~0xf, %rsp                     /* realign the stack */
        call    efi_main
        movq    %rax,%rsi
-       cmpq    $0,%rax
-       jne     2f
-fail:
-       /* EFI init failed, so hang. */
-       hlt
-       jmp     fail
-2:
        movl    BP_code32_start(%esi), %eax
        leaq    startup_64(%rax), %rax
        jmp     *%rax
-SYM_FUNC_END(efi_pe_entry)
-
-       .org 0x390
-SYM_FUNC_START(efi64_stub_entry)
-       movq    %rdi, efi64_config(%rip)        /* Handle */
-       movq    %rsi, efi64_config+8(%rip) /* EFI System table pointer */
-
-       leaq    efi64_config(%rip), %rax
-       movq    %rax, efi_config(%rip)
-
-       movq    %rdx, %rsi
-       jmp     handover_entry
 SYM_FUNC_END(efi64_stub_entry)
+SYM_FUNC_END_ALIAS(efi_stub_entry)
 #endif
 
        .text
@@ -663,22 +627,10 @@ SYM_DATA_START_LOCAL(gdt)
        .quad   0x0000000000000000      /* TS continued */
 SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
 
-#ifdef CONFIG_EFI_STUB
-SYM_DATA_LOCAL(efi_config, .quad 0)
-
 #ifdef CONFIG_EFI_MIXED
-SYM_DATA_START(efi32_config)
-       .fill   5,8,0
-       .byte   0
-SYM_DATA_END(efi32_config)
+SYM_DATA_LOCAL(efi32_boot_args, .long 0)
 #endif
 
-SYM_DATA_START(efi64_config)
-       .fill   5,8,0
-       .byte   1
-SYM_DATA_END(efi64_config)
-#endif /* CONFIG_EFI_STUB */
-
 /*
  * Stack and heap for uncompression
  */
index 001905d..1817f35 100644 (file)
@@ -200,32 +200,14 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
 
 /* arch specific definitions used by the stub code */
 
-struct efi_config {
-       u64 image_handle;
-       u64 table;
-       u64 runtime_services;
-       u64 boot_services;
-       u64 text_output;
-       bool is64;
-} __packed;
-
-__pure const struct efi_config *__efi_early(void);
-
-static inline bool efi_is_64bit(void)
-{
-       if (!IS_ENABLED(CONFIG_X86_64))
-               return false;
-
-       if (!IS_ENABLED(CONFIG_EFI_MIXED))
-               return true;
-
-       return __efi_early()->is64;
-}
+__pure bool efi_is_64bit(void);
 
 static inline bool efi_is_native(void)
 {
        if (!IS_ENABLED(CONFIG_X86_64))
                return true;
+       if (!IS_ENABLED(CONFIG_EFI_MIXED))
+               return true;
        return efi_is_64bit();
 }
 
@@ -252,18 +234,16 @@ static inline bool efi_is_native(void)
 
 #define efi_call_early(f, ...)                                         \
        (efi_is_native()                                                \
-               ? ((efi_boot_services_t *)(unsigned long)               \
-                       __efi_early()->boot_services)->f(__VA_ARGS__)   \
-               : efi64_thunk(((efi_boot_services_t *)(unsigned long)   \
-                       __efi_early()->boot_services)->mixed_mode.f,    \
+               ? efi_system_table()->boottime->f(__VA_ARGS__)          \
+               : efi64_thunk(efi_table_attr(efi_boot_services,         \
+                       boottime, efi_system_table())->mixed_mode.f,    \
                        __VA_ARGS__))
 
 #define efi_call_runtime(f, ...)                                       \
        (efi_is_native()                                                \
-               ? ((efi_runtime_services_t *)(unsigned long)            \
-                       __efi_early()->runtime_services)->f(__VA_ARGS__)\
-               : efi64_thunk(((efi_runtime_services_t *)(unsigned long)\
-                       __efi_early()->runtime_services)->mixed_mode.f, \
+               ? efi_system_table()->runtime->f(__VA_ARGS__)           \
+               : efi64_thunk(efi_table_attr(efi_runtime_services,      \
+                       runtime, efi_system_table())->mixed_mode.f,     \
                        __VA_ARGS__))
 
 extern bool efi_reboot_required(void);