efi/libstub: Move file I/O support code into separate file
authorArd Biesheuvel <ardb@kernel.org>
Mon, 10 Feb 2020 16:02:43 +0000 (17:02 +0100)
committerArd Biesheuvel <ardb@kernel.org>
Sun, 23 Feb 2020 20:57:15 +0000 (21:57 +0100)
Split off the file I/O support code into a separate source file so
it ends up in a separate object file in the static library, allowing
the linker to omit it if the routines are not used.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
drivers/firmware/efi/libstub/Makefile
drivers/firmware/efi/libstub/efi-stub-helper.c
drivers/firmware/efi/libstub/efistub.h
drivers/firmware/efi/libstub/file.c [new file with mode: 0644]

index a07b044..1202c9e 100644 (file)
@@ -40,7 +40,7 @@ OBJECT_FILES_NON_STANDARD     := y
 KCOV_INSTRUMENT                        := n
 
 lib-y                          := efi-stub-helper.o gop.o secureboot.o tpm.o \
-                                  mem.o random.o randomalloc.o pci.o
+                                  file.o mem.o random.o randomalloc.o pci.o
 
 # include the stub's generic dependencies from lib/ when building for ARM/arm64
 arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
index 1a8f2cf..db23be5 100644 (file)
 
 #include "efistub.h"
 
-/*
- * Some firmware implementations have problems reading files in one go.
- * A read chunk size of 1MB seems to work for most platforms.
- *
- * Unfortunately, reading files in chunks triggers *other* bugs on some
- * platforms, so we provide a way to disable this workaround, which can
- * be done by passing "efi=nochunk" on the EFI boot stub command line.
- *
- * If you experience issues with initrd images being corrupt it's worth
- * trying efi=nochunk, but chunking is enabled by default because there
- * are far more machines that require the workaround than those that
- * break with it enabled.
- */
-#define EFI_READ_CHUNK_SIZE    (1024 * 1024)
-
-static unsigned long efi_chunk_size = EFI_READ_CHUNK_SIZE;
-
+static bool __efistub_global efi_nochunk;
 static bool __efistub_global efi_nokaslr;
 static bool __efistub_global efi_quiet;
 static bool __efistub_global efi_novamap;
@@ -36,6 +20,10 @@ static bool __efistub_global efi_nosoftreserve;
 static bool __efistub_global efi_disable_pci_dma =
                                        IS_ENABLED(CONFIG_EFI_DISABLE_PCI_DMA);
 
+bool __pure nochunk(void)
+{
+       return efi_nochunk;
+}
 bool __pure nokaslr(void)
 {
        return efi_nokaslr;
@@ -53,11 +41,6 @@ bool __pure __efi_soft_reserve_enabled(void)
        return !efi_nosoftreserve;
 }
 
-struct file_info {
-       efi_file_protocol_t *handle;
-       u64 size;
-};
-
 void efi_printk(char *str)
 {
        char *s8;
@@ -75,90 +58,6 @@ void efi_printk(char *str)
        }
 }
 
-static efi_status_t efi_file_size(void *__fh, efi_char16_t *filename_16,
-                                 void **handle, u64 *file_sz)
-{
-       efi_file_protocol_t *h, *fh = __fh;
-       efi_file_info_t *info;
-       efi_status_t status;
-       efi_guid_t info_guid = EFI_FILE_INFO_ID;
-       unsigned long info_sz;
-
-       status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, 0);
-       if (status != EFI_SUCCESS) {
-               efi_printk("Failed to open file: ");
-               efi_char16_printk(filename_16);
-               efi_printk("\n");
-               return status;
-       }
-
-       *handle = h;
-
-       info_sz = 0;
-       status = h->get_info(h, &info_guid, &info_sz, NULL);
-       if (status != EFI_BUFFER_TOO_SMALL) {
-               efi_printk("Failed to get file info size\n");
-               return status;
-       }
-
-grow:
-       status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, info_sz,
-                            (void **)&info);
-       if (status != EFI_SUCCESS) {
-               efi_printk("Failed to alloc mem for file info\n");
-               return status;
-       }
-
-       status = h->get_info(h, &info_guid, &info_sz, info);
-       if (status == EFI_BUFFER_TOO_SMALL) {
-               efi_bs_call(free_pool, info);
-               goto grow;
-       }
-
-       *file_sz = info->file_size;
-       efi_bs_call(free_pool, info);
-
-       if (status != EFI_SUCCESS)
-               efi_printk("Failed to get initrd info\n");
-
-       return status;
-}
-
-static efi_status_t efi_file_read(efi_file_protocol_t *handle,
-                                 unsigned long *size, void *addr)
-{
-       return handle->read(handle, size, addr);
-}
-
-static efi_status_t efi_file_close(efi_file_protocol_t *handle)
-{
-       return handle->close(handle);
-}
-
-static efi_status_t efi_open_volume(efi_loaded_image_t *image,
-                                   efi_file_protocol_t **__fh)
-{
-       efi_simple_file_system_protocol_t *io;
-       efi_file_protocol_t *fh;
-       efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
-       efi_status_t status;
-       efi_handle_t handle = image->device_handle;
-
-       status = efi_bs_call(handle_protocol, handle, &fs_proto, (void **)&io);
-       if (status != EFI_SUCCESS) {
-               efi_printk("Failed to handle fs_proto\n");
-               return status;
-       }
-
-       status = io->open_volume(io, &fh);
-       if (status != EFI_SUCCESS)
-               efi_printk("Failed to open volume\n");
-       else
-               *__fh = fh;
-
-       return status;
-}
-
 /*
  * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
  * option, e.g. efi=nochunk.
@@ -197,7 +96,7 @@ efi_status_t efi_parse_options(char const *cmdline)
        while (*str && *str != ' ') {
                if (!strncmp(str, "nochunk", 7)) {
                        str += strlen("nochunk");
-                       efi_chunk_size = -1UL;
+                       efi_nochunk = true;
                }
 
                if (!strncmp(str, "novamap", 7)) {
@@ -232,187 +131,6 @@ efi_status_t efi_parse_options(char const *cmdline)
        return EFI_SUCCESS;
 }
 
-/*
- * Check the cmdline for a LILO-style file= arguments.
- *
- * We only support loading a file from the same filesystem as
- * the kernel image.
- */
-efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
-                                 char *cmd_line, char *option_string,
-                                 unsigned long max_addr,
-                                 unsigned long *load_addr,
-                                 unsigned long *load_size)
-{
-       struct file_info *files;
-       unsigned long file_addr;
-       u64 file_size_total;
-       efi_file_protocol_t *fh = NULL;
-       efi_status_t status;
-       int nr_files;
-       char *str;
-       int i, j, k;
-
-       file_addr = 0;
-       file_size_total = 0;
-
-       str = cmd_line;
-
-       j = 0;                  /* See close_handles */
-
-       if (!load_addr || !load_size)
-               return EFI_INVALID_PARAMETER;
-
-       *load_addr = 0;
-       *load_size = 0;
-
-       if (!str || !*str)
-               return EFI_SUCCESS;
-
-       for (nr_files = 0; *str; nr_files++) {
-               str = strstr(str, option_string);
-               if (!str)
-                       break;
-
-               str += strlen(option_string);
-
-               /* Skip any leading slashes */
-               while (*str == '/' || *str == '\\')
-                       str++;
-
-               while (*str && *str != ' ' && *str != '\n')
-                       str++;
-       }
-
-       if (!nr_files)
-               return EFI_SUCCESS;
-
-       status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
-                            nr_files * sizeof(*files), (void **)&files);
-       if (status != EFI_SUCCESS) {
-               pr_efi_err("Failed to alloc mem for file handle list\n");
-               goto fail;
-       }
-
-       str = cmd_line;
-       for (i = 0; i < nr_files; i++) {
-               struct file_info *file;
-               efi_char16_t filename_16[256];
-               efi_char16_t *p;
-
-               str = strstr(str, option_string);
-               if (!str)
-                       break;
-
-               str += strlen(option_string);
-
-               file = &files[i];
-               p = filename_16;
-
-               /* Skip any leading slashes */
-               while (*str == '/' || *str == '\\')
-                       str++;
-
-               while (*str && *str != ' ' && *str != '\n') {
-                       if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
-                               break;
-
-                       if (*str == '/') {
-                               *p++ = '\\';
-                               str++;
-                       } else {
-                               *p++ = *str++;
-                       }
-               }
-
-               *p = '\0';
-
-               /* Only open the volume once. */
-               if (!i) {
-                       status = efi_open_volume(image, &fh);
-                       if (status != EFI_SUCCESS)
-                               goto free_files;
-               }
-
-               status = efi_file_size(fh, filename_16, (void **)&file->handle,
-                                      &file->size);
-               if (status != EFI_SUCCESS)
-                       goto close_handles;
-
-               file_size_total += file->size;
-       }
-
-       if (file_size_total) {
-               unsigned long addr;
-
-               /*
-                * Multiple files need to be at consecutive addresses in memory,
-                * so allocate enough memory for all the files.  This is used
-                * for loading multiple files.
-                */
-               status = efi_allocate_pages(file_size_total, &file_addr, max_addr);
-               if (status != EFI_SUCCESS) {
-                       pr_efi_err("Failed to alloc highmem for files\n");
-                       goto close_handles;
-               }
-
-               /* We've run out of free low memory. */
-               if (file_addr > max_addr) {
-                       pr_efi_err("We've run out of free low memory\n");
-                       status = EFI_INVALID_PARAMETER;
-                       goto free_file_total;
-               }
-
-               addr = file_addr;
-               for (j = 0; j < nr_files; j++) {
-                       unsigned long size;
-
-                       size = files[j].size;
-                       while (size) {
-                               unsigned long chunksize;
-
-                               if (IS_ENABLED(CONFIG_X86) && size > efi_chunk_size)
-                                       chunksize = efi_chunk_size;
-                               else
-                                       chunksize = size;
-
-                               status = efi_file_read(files[j].handle,
-                                                      &chunksize,
-                                                      (void *)addr);
-                               if (status != EFI_SUCCESS) {
-                                       pr_efi_err("Failed to read file\n");
-                                       goto free_file_total;
-                               }
-                               addr += chunksize;
-                               size -= chunksize;
-                       }
-
-                       efi_file_close(files[j].handle);
-               }
-
-       }
-
-       efi_bs_call(free_pool, files);
-
-       *load_addr = file_addr;
-       *load_size = file_size_total;
-
-       return status;
-
-free_file_total:
-       efi_free(file_size_total, file_addr);
-
-close_handles:
-       for (k = j; k < i; k++)
-               efi_file_close(files[k].handle);
-free_files:
-       efi_bs_call(free_pool, files);
-fail:
-       *load_addr = 0;
-       *load_size = 0;
-
-       return status;
-}
 /*
  * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
  * This overestimates for surrogates, but that is okay.
index 5123def..e057d50 100644 (file)
@@ -31,6 +31,7 @@
 #define __efistub_global
 #endif
 
+extern bool __pure nochunk(void);
 extern bool __pure nokaslr(void);
 extern bool __pure is_quiet(void);
 extern bool __pure novamap(void);
diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c
new file mode 100644 (file)
index 0000000..e0302f3
--- /dev/null
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helper functions used by the EFI stub on multiple
+ * architectures. This should be #included by the EFI stub
+ * implementation files.
+ *
+ * Copyright 2011 Intel Corporation; author Matt Fleming
+ */
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+/*
+ * Some firmware implementations have problems reading files in one go.
+ * A read chunk size of 1MB seems to work for most platforms.
+ *
+ * Unfortunately, reading files in chunks triggers *other* bugs on some
+ * platforms, so we provide a way to disable this workaround, which can
+ * be done by passing "efi=nochunk" on the EFI boot stub command line.
+ *
+ * If you experience issues with initrd images being corrupt it's worth
+ * trying efi=nochunk, but chunking is enabled by default on x86 because
+ * there are far more machines that require the workaround than those that
+ * break with it enabled.
+ */
+#define EFI_READ_CHUNK_SIZE    SZ_1M
+
+struct file_info {
+       efi_file_protocol_t *handle;
+       u64 size;
+};
+
+static efi_status_t efi_file_size(void *__fh, efi_char16_t *filename_16,
+                                 void **handle, u64 *file_sz)
+{
+       efi_file_protocol_t *h, *fh = __fh;
+       efi_file_info_t *info;
+       efi_status_t status;
+       efi_guid_t info_guid = EFI_FILE_INFO_ID;
+       unsigned long info_sz;
+
+       status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, 0);
+       if (status != EFI_SUCCESS) {
+               efi_printk("Failed to open file: ");
+               efi_char16_printk(filename_16);
+               efi_printk("\n");
+               return status;
+       }
+
+       *handle = h;
+
+       info_sz = 0;
+       status = h->get_info(h, &info_guid, &info_sz, NULL);
+       if (status != EFI_BUFFER_TOO_SMALL) {
+               efi_printk("Failed to get file info size\n");
+               return status;
+       }
+
+grow:
+       status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, info_sz,
+                            (void **)&info);
+       if (status != EFI_SUCCESS) {
+               efi_printk("Failed to alloc mem for file info\n");
+               return status;
+       }
+
+       status = h->get_info(h, &info_guid, &info_sz, info);
+       if (status == EFI_BUFFER_TOO_SMALL) {
+               efi_bs_call(free_pool, info);
+               goto grow;
+       }
+
+       *file_sz = info->file_size;
+       efi_bs_call(free_pool, info);
+
+       if (status != EFI_SUCCESS)
+               efi_printk("Failed to get initrd info\n");
+
+       return status;
+}
+
+static efi_status_t efi_file_read(efi_file_protocol_t *handle,
+                                 unsigned long *size, void *addr)
+{
+       return handle->read(handle, size, addr);
+}
+
+static efi_status_t efi_file_close(efi_file_protocol_t *handle)
+{
+       return handle->close(handle);
+}
+
+static efi_status_t efi_open_volume(efi_loaded_image_t *image,
+                                   efi_file_protocol_t **__fh)
+{
+       efi_simple_file_system_protocol_t *io;
+       efi_file_protocol_t *fh;
+       efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
+       efi_status_t status;
+       efi_handle_t handle = image->device_handle;
+
+       status = efi_bs_call(handle_protocol, handle, &fs_proto, (void **)&io);
+       if (status != EFI_SUCCESS) {
+               efi_printk("Failed to handle fs_proto\n");
+               return status;
+       }
+
+       status = io->open_volume(io, &fh);
+       if (status != EFI_SUCCESS)
+               efi_printk("Failed to open volume\n");
+       else
+               *__fh = fh;
+
+       return status;
+}
+
+/*
+ * Check the cmdline for a LILO-style file= arguments.
+ *
+ * We only support loading a file from the same filesystem as
+ * the kernel image.
+ */
+efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
+                                 char *cmd_line, char *option_string,
+                                 unsigned long max_addr,
+                                 unsigned long *load_addr,
+                                 unsigned long *load_size)
+{
+       unsigned long efi_chunk_size = ULONG_MAX;
+       struct file_info *files;
+       unsigned long file_addr;
+       u64 file_size_total;
+       efi_file_protocol_t *fh = NULL;
+       efi_status_t status;
+       int nr_files;
+       char *str;
+       int i, j, k;
+
+       if (IS_ENABLED(CONFIG_X86) && !nochunk())
+               efi_chunk_size = EFI_READ_CHUNK_SIZE;
+
+       file_addr = 0;
+       file_size_total = 0;
+
+       str = cmd_line;
+
+       j = 0;                  /* See close_handles */
+
+       if (!load_addr || !load_size)
+               return EFI_INVALID_PARAMETER;
+
+       *load_addr = 0;
+       *load_size = 0;
+
+       if (!str || !*str)
+               return EFI_SUCCESS;
+
+       for (nr_files = 0; *str; nr_files++) {
+               str = strstr(str, option_string);
+               if (!str)
+                       break;
+
+               str += strlen(option_string);
+
+               /* Skip any leading slashes */
+               while (*str == '/' || *str == '\\')
+                       str++;
+
+               while (*str && *str != ' ' && *str != '\n')
+                       str++;
+       }
+
+       if (!nr_files)
+               return EFI_SUCCESS;
+
+       status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
+                            nr_files * sizeof(*files), (void **)&files);
+       if (status != EFI_SUCCESS) {
+               pr_efi_err("Failed to alloc mem for file handle list\n");
+               goto fail;
+       }
+
+       str = cmd_line;
+       for (i = 0; i < nr_files; i++) {
+               struct file_info *file;
+               efi_char16_t filename_16[256];
+               efi_char16_t *p;
+
+               str = strstr(str, option_string);
+               if (!str)
+                       break;
+
+               str += strlen(option_string);
+
+               file = &files[i];
+               p = filename_16;
+
+               /* Skip any leading slashes */
+               while (*str == '/' || *str == '\\')
+                       str++;
+
+               while (*str && *str != ' ' && *str != '\n') {
+                       if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
+                               break;
+
+                       if (*str == '/') {
+                               *p++ = '\\';
+                               str++;
+                       } else {
+                               *p++ = *str++;
+                       }
+               }
+
+               *p = '\0';
+
+               /* Only open the volume once. */
+               if (!i) {
+                       status = efi_open_volume(image, &fh);
+                       if (status != EFI_SUCCESS)
+                               goto free_files;
+               }
+
+               status = efi_file_size(fh, filename_16, (void **)&file->handle,
+                                      &file->size);
+               if (status != EFI_SUCCESS)
+                       goto close_handles;
+
+               file_size_total += file->size;
+       }
+
+       if (file_size_total) {
+               unsigned long addr;
+
+               /*
+                * Multiple files need to be at consecutive addresses in memory,
+                * so allocate enough memory for all the files.  This is used
+                * for loading multiple files.
+                */
+               status = efi_allocate_pages(file_size_total, &file_addr, max_addr);
+               if (status != EFI_SUCCESS) {
+                       pr_efi_err("Failed to alloc highmem for files\n");
+                       goto close_handles;
+               }
+
+               /* We've run out of free low memory. */
+               if (file_addr > max_addr) {
+                       pr_efi_err("We've run out of free low memory\n");
+                       status = EFI_INVALID_PARAMETER;
+                       goto free_file_total;
+               }
+
+               addr = file_addr;
+               for (j = 0; j < nr_files; j++) {
+                       unsigned long size;
+
+                       size = files[j].size;
+                       while (size) {
+                               unsigned long chunksize;
+
+                               if (size > efi_chunk_size)
+                                       chunksize = efi_chunk_size;
+                               else
+                                       chunksize = size;
+
+                               status = efi_file_read(files[j].handle,
+                                                      &chunksize,
+                                                      (void *)addr);
+                               if (status != EFI_SUCCESS) {
+                                       pr_efi_err("Failed to read file\n");
+                                       goto free_file_total;
+                               }
+                               addr += chunksize;
+                               size -= chunksize;
+                       }
+
+                       efi_file_close(files[j].handle);
+               }
+
+       }
+
+       efi_bs_call(free_pool, files);
+
+       *load_addr = file_addr;
+       *load_size = file_size_total;
+
+       return status;
+
+free_file_total:
+       efi_free(file_size_total, file_addr);
+
+close_handles:
+       for (k = j; k < i; k++)
+               efi_file_close(files[k].handle);
+free_files:
+       efi_bs_call(free_pool, files);
+fail:
+       *load_addr = 0;
+       *load_size = 0;
+
+       return status;
+}