Commit 2e6fa86f authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

efi: libstub: Enable efi_printk() in zboot decompressor 



Split the efi_printk() routine into its own source file, and provide
local implementations of strlen() and strnlen() so that the standalone
zboot app can efi_err and efi_info etc.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 52dce39c

arch/arm64/kernel/image-vars.h

+0 −2
Original line number Diff line number Diff line
@@ -22,8 +22,6 @@ PROVIDE(__efistub_primary_entry_offset = primary_entry - _text); 
 * position independent manner

 */

PROVIDE(__efistub_memchr		= __pi_memchr);

PROVIDE(__efistub_strlen		= __pi_strlen);

PROVIDE(__efistub_strnlen		= __pi_strnlen);

PROVIDE(__efistub_strcmp		= __pi_strcmp);

PROVIDE(__efistub_strrchr		= __pi_strrchr);

PROVIDE(__efistub_dcache_clean_poc	= __pi_dcache_clean_poc);

arch/loongarch/kernel/image-vars.h

+0 −2
Original line number Diff line number Diff line
@@ -10,10 +10,8 @@ 
__efistub_memchr		= memchr;

__efistub_strcat		= strcat;

__efistub_strcmp		= strcmp;

__efistub_strlen		= strlen;

__efistub_strncat		= strncat;

__efistub_strnstr		= strnstr;

__efistub_strnlen		= strnlen;

__efistub_strrchr		= strrchr;

__efistub_kernel_entry		= kernel_entry;

__efistub_kernel_asize		= kernel_asize;

arch/riscv/kernel/image-vars.h

+0 −2
Original line number Diff line number Diff line
@@ -24,8 +24,6 @@ 
 * position independent manner

 */

__efistub_memchr		= memchr;

__efistub_strlen		= strlen;

__efistub_strnlen		= strnlen;

__efistub_strcmp		= strcmp;

__efistub_strrchr		= strrchr;

drivers/firmware/efi/libstub/Makefile

+3 −2
Original line number Diff line number Diff line
@@ -24,7 +24,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \ 
# disable the stackleak plugin

cflags-$(CONFIG_ARM64)		+= -fpie $(DISABLE_STACKLEAK_PLUGIN) \

				   $(call cc-option,-mbranch-protection=none)

cflags-$(CONFIG_ARM)		+= -fno-builtin -fpic \

cflags-$(CONFIG_ARM)		+= -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \

				   -fno-builtin -fpic \

				   $(call cc-option,-mno-single-pic-base)

cflags-$(CONFIG_RISCV)		+= -fpic

cflags-$(CONFIG_LOONGARCH)	+= -fpie
@@ -68,7 +69,7 @@ KCOV_INSTRUMENT := n 
lib-y				:= efi-stub-helper.o gop.o secureboot.o tpm.o \

				   file.o mem.o random.o randomalloc.o pci.o \

				   skip_spaces.o lib-cmdline.o lib-ctype.o \

				   alignedmem.o relocate.o vsprintf.o

				   alignedmem.o relocate.o printk.o vsprintf.o



# include the stub's libfdt dependencies from lib/ when needed

libfdt-deps			:= fdt_rw.c fdt_ro.c fdt_wip.c fdt.c \

drivers/firmware/efi/libstub/efi-stub-helper.c

+0 −143
Original line number Diff line number Diff line
@@ -9,10 +9,8 @@ 


#include <linux/stdarg.h>



#include <linux/ctype.h>

#include <linux/efi.h>

#include <linux/kernel.h>

#include <linux/printk.h> /* For CONSOLE_LOGLEVEL_* */

#include <asm/efi.h>

#include <asm/setup.h>
@@ -20,7 +18,6 @@ 


bool efi_nochunk;

bool efi_nokaslr = !IS_ENABLED(CONFIG_RANDOMIZE_BASE);

int efi_loglevel = CONSOLE_LOGLEVEL_DEFAULT;

bool efi_novamap;



static bool efi_noinitrd;
@@ -32,146 +29,6 @@ bool __pure __efi_soft_reserve_enabled(void) 
	return !efi_nosoftreserve;

}



/**

 * efi_char16_puts() - Write a UCS-2 encoded string to the console

 * @str:	UCS-2 encoded string

 */

void efi_char16_puts(efi_char16_t *str)

{

	efi_call_proto(efi_table_attr(efi_system_table, con_out),

		       output_string, str);

}



static

u32 utf8_to_utf32(const u8 **s8)

{

	u32 c32;

	u8 c0, cx;

	size_t clen, i;



	c0 = cx = *(*s8)++;

	/*

	 * The position of the most-significant 0 bit gives us the length of

	 * a multi-octet encoding.

	 */

	for (clen = 0; cx & 0x80; ++clen)

		cx <<= 1;

	/*

	 * If the 0 bit is in position 8, this is a valid single-octet

	 * encoding. If the 0 bit is in position 7 or positions 1-3, the

	 * encoding is invalid.

	 * In either case, we just return the first octet.

	 */

	if (clen < 2 || clen > 4)

		return c0;

	/* Get the bits from the first octet. */

	c32 = cx >> clen--;

	for (i = 0; i < clen; ++i) {

		/* Trailing octets must have 10 in most significant bits. */

		cx = (*s8)[i] ^ 0x80;

		if (cx & 0xc0)

			return c0;

		c32 = (c32 << 6) | cx;

	}

	/*

	 * Check for validity:

	 * - The character must be in the Unicode range.

	 * - It must not be a surrogate.

	 * - It must be encoded using the correct number of octets.

	 */

	if (c32 > 0x10ffff ||

	    (c32 & 0xf800) == 0xd800 ||

	    clen != (c32 >= 0x80) + (c32 >= 0x800) + (c32 >= 0x10000))

		return c0;

	*s8 += clen;

	return c32;

}



/**

 * efi_puts() - Write a UTF-8 encoded string to the console

 * @str:	UTF-8 encoded string

 */

void efi_puts(const char *str)

{

	efi_char16_t buf[128];

	size_t pos = 0, lim = ARRAY_SIZE(buf);

	const u8 *s8 = (const u8 *)str;

	u32 c32;



	while (*s8) {

		if (*s8 == '\n')

			buf[pos++] = L'\r';

		c32 = utf8_to_utf32(&s8);

		if (c32 < 0x10000) {

			/* Characters in plane 0 use a single word. */

			buf[pos++] = c32;

		} else {

			/*

			 * Characters in other planes encode into a surrogate

			 * pair.

			 */

			buf[pos++] = (0xd800 - (0x10000 >> 10)) + (c32 >> 10);

			buf[pos++] = 0xdc00 + (c32 & 0x3ff);

		}

		if (*s8 == '\0' || pos >= lim - 2) {

			buf[pos] = L'\0';

			efi_char16_puts(buf);

			pos = 0;

		}

	}

}



/**

 * efi_printk() - Print a kernel message

 * @fmt:	format string

 *

 * The first letter of the format string is used to determine the logging level

 * of the message. If the level is less then the current EFI logging level, the

 * message is suppressed. The message will be truncated to 255 bytes.

 *

 * Return:	number of printed characters

 */

int efi_printk(const char *fmt, ...)

{

	char printf_buf[256];

	va_list args;

	int printed;

	int loglevel = printk_get_level(fmt);



	switch (loglevel) {

	case '0' ... '9':

		loglevel -= '0';

		break;

	default:

		/*

		 * Use loglevel -1 for cases where we just want to print to

		 * the screen.

		 */

		loglevel = -1;

		break;

	}



	if (loglevel >= efi_loglevel)

		return 0;



	if (loglevel >= 0)

		efi_puts("EFI stub: ");



	fmt = printk_skip_level(fmt);



	va_start(args, fmt);

	printed = vsnprintf(printf_buf, sizeof(printf_buf), fmt, args);

	va_end(args);



	efi_puts(printf_buf);

	if (printed >= sizeof(printf_buf)) {

		efi_puts("[Message truncated]\n");

		return -1;

	}



	return printed;

}



/**

 * efi_parse_options() - Parse EFI command line options

 * @cmdline:	kernel command line