From 5cd28e17600458ee99e69a86856f2b7e8eddd0c0 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 3 Oct 2020 12:44:31 +0200 Subject: efi_loader: description EFI_LOAD_FILE2_PROTOCOL U-Boot offers a EFI_LOAD_FILE2_PROTOCOL which the Linux EFI stub can use to load an initial RAM disk. Update the function comments of the implementation. Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas --- lib/efi_loader/efi_load_initrd.c | 42 ++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 19 deletions(-) (limited to 'lib/efi_loader/efi_load_initrd.c') diff --git a/lib/efi_loader/efi_load_initrd.c b/lib/efi_loader/efi_load_initrd.c index 574a83d7e30..ff69e6eb79b 100644 --- a/lib/efi_loader/efi_load_initrd.c +++ b/lib/efi_loader/efi_load_initrd.c @@ -47,9 +47,9 @@ static const struct efi_initrd_dp dp = { /** * get_file_size() - retrieve the size of initramfs, set efi status on error * - * @dev: device to read from. i.e "mmc" - * @part: device partition. i.e "0:1" - * @file: name fo file + * @dev: device to read from, e.g. "mmc" + * @part: device partition, e.g. "0:1" + * @file: name of file * @status: EFI exit code in case of failure * * Return: size of file @@ -78,15 +78,16 @@ out: } /** - * load_file2() - get information about random number generation + * efi_load_file2initrd() - load initial RAM disk + * + * This function implements the LoadFile service of the EFI_LOAD_FILE2_PROTOCOL + * in order to load an initial RAM disk requested by the Linux kernel stub. * - * This function implement the LoadFile2() service in order to load an initram - * disk requested by the Linux kernel stub. * See the UEFI spec for details. * - * @this: loadfile2 protocol instance - * @file_path: relative path of the file. "" in this case - * @boot_policy: must be false for Loadfile2 + * @this: EFI_LOAD_FILE2_PROTOCOL instance + * @file_path: media device path of the file, "" in this case + * @boot_policy: must be false * @buffer_size: size of allocated buffer * @buffer: buffer to load the file * @@ -128,7 +129,13 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this, goto out; } - /* expect something like 'mmc 0:1 initrd.cpio.gz' */ + /* + * expect a string with three space separated parts: + * + * * a block device type, e.g. "mmc" + * * a device and partition identifier, e.g. "0:1" + * * a file path on the block device, e.g. "/boot/initrd.cpio.gz" + */ dev = strsep(&s, " "); if (!dev) goto out; @@ -168,23 +175,20 @@ out: } /** - * efi_initrd_register() - Register a handle and loadfile2 protocol + * efi_initrd_register() - create handle for loading initial RAM disk * - * This function creates a new handle and installs a linux specific GUID - * to handle initram disk loading during boot. - * See the UEFI spec for details. + * This function creates a new handle and installs a Linux specific vendor + * device path and an EFI_LOAD_FILE_2_PROTOCOL. Linux uses the device path + * to identify the handle and then calls the LoadFile service of the + * EFI_LOAD_FILE_2_PROTOCOL to read the initial RAM disk. * - * Return: status code + * Return: status code */ efi_status_t efi_initrd_register(void) { efi_handle_t efi_initrd_handle = NULL; efi_status_t ret; - /* - * Set up the handle with the EFI_LOAD_FILE2_PROTOCOL which Linux may - * use to load the initial ramdisk. - */ ret = EFI_CALL(efi_install_multiple_protocol_interfaces (&efi_initrd_handle, /* initramfs */ -- cgit v1.2.3 From e2aff337ed53ada0abdbc38d0afa8d6f209bf4ab Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 3 Oct 2020 12:50:52 +0200 Subject: efi_loader: illegal free in EFI_LOAD_FILE2_PROTOCOL strsep() changes the address that its first argument points to. We cannot use the changed address as argument of free(). Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas --- lib/efi_loader/efi_load_initrd.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'lib/efi_loader/efi_load_initrd.c') diff --git a/lib/efi_loader/efi_load_initrd.c b/lib/efi_loader/efi_load_initrd.c index ff69e6eb79b..d517d686c33 100644 --- a/lib/efi_loader/efi_load_initrd.c +++ b/lib/efi_loader/efi_load_initrd.c @@ -98,19 +98,20 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this, struct efi_device_path *file_path, bool boot_policy, efi_uintn_t *buffer_size, void *buffer) { - const char *filespec = CONFIG_EFI_INITRD_FILESPEC; + char *filespec; efi_status_t status = EFI_NOT_FOUND; loff_t file_sz = 0, read_sz = 0; char *dev, *part, *file; - char *s; + char *pos; int ret; EFI_ENTRY("%p, %p, %d, %p, %p", this, file_path, boot_policy, buffer_size, buffer); - s = strdup(filespec); - if (!s) + filespec = strdup(CONFIG_EFI_INITRD_FILESPEC); + if (!filespec) goto out; + pos = filespec; if (!this || this != &efi_lf2_protocol || !buffer_size) { @@ -136,13 +137,13 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this, * * a device and partition identifier, e.g. "0:1" * * a file path on the block device, e.g. "/boot/initrd.cpio.gz" */ - dev = strsep(&s, " "); + dev = strsep(&pos, " "); if (!dev) goto out; - part = strsep(&s, " "); + part = strsep(&pos, " "); if (!part) goto out; - file = strsep(&s, " "); + file = strsep(&pos, " "); if (!file) goto out; @@ -170,7 +171,7 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this, } out: - free(s); + free(filespec); return EFI_EXIT(status); } -- cgit v1.2.3