[PATCH 4.9 60/83] efi/libstub: Unify command line param parsing

From: Greg Kroah-Hartman
Date: Sun Jun 09 2019 - 13:19:38 EST


From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>

commit 60f38de7a8d4e816100ceafd1b382df52527bd50 upstream.

Merge the parsing of the command line carried out in arm-stub.c with
the handling in efi_parse_options(). Note that this also fixes the
missing handling of CONFIG_CMDLINE_FORCE=y, in which case the builtin
command line should supersede the one passed by the firmware.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: bhe@xxxxxxxxxx
Cc: bhsharma@xxxxxxxxxx
Cc: bp@xxxxxxxxx
Cc: eugene@xxxxxx
Cc: evgeny.kalugin@xxxxxxxxx
Cc: jhugo@xxxxxxxxxxxxxx
Cc: leif.lindholm@xxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Cc: mark.rutland@xxxxxxx
Cc: roy.franz@xxxxxxxxxx
Cc: rruigrok@xxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20170404160910.28115-1-ard.biesheuvel@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
[ardb: fix up merge conflicts with 4.9.180]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/firmware/efi/libstub/arm-stub.c | 23 +++++++----------------
drivers/firmware/efi/libstub/arm64-stub.c | 4 +---
drivers/firmware/efi/libstub/efi-stub-helper.c | 19 +++++++++++--------
drivers/firmware/efi/libstub/efistub.h | 2 ++
include/linux/efi.h | 2 +-
5 files changed, 22 insertions(+), 28 deletions(-)

--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -18,7 +18,6 @@

#include "efistub.h"

-bool __nokaslr;

static int efi_get_secureboot(efi_system_table_t *sys_table_arg)
{
@@ -268,18 +267,6 @@ unsigned long efi_entry(void *handle, ef
goto fail;
}

- /* check whether 'nokaslr' was passed on the command line */
- if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
- static const u8 default_cmdline[] = CONFIG_CMDLINE;
- const u8 *str, *cmdline = cmdline_ptr;
-
- if (IS_ENABLED(CONFIG_CMDLINE_FORCE))
- cmdline = default_cmdline;
- str = strstr(cmdline, "nokaslr");
- if (str == cmdline || (str > cmdline && *(str - 1) == ' '))
- __nokaslr = true;
- }
-
si = setup_graphics(sys_table);

status = handle_kernel_image(sys_table, image_addr, &image_size,
@@ -291,9 +278,13 @@ unsigned long efi_entry(void *handle, ef
goto fail_free_cmdline;
}

- status = efi_parse_options(cmdline_ptr);
- if (status != EFI_SUCCESS)
- pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");
+ if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+ IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+ cmdline_size == 0)
+ efi_parse_options(CONFIG_CMDLINE);
+
+ if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
+ efi_parse_options(cmdline_ptr);

secure_boot = efi_get_secureboot(sys_table);
if (secure_boot > 0)
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -24,8 +24,6 @@

#include "efistub.h"

-extern bool __nokaslr;
-
efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
{
u64 tg;
@@ -60,7 +58,7 @@ efi_status_t handle_kernel_image(efi_sys
u64 phys_seed = 0;

if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
- if (!__nokaslr) {
+ if (!nokaslr()) {
status = efi_get_random_bytes(sys_table_arg,
sizeof(phys_seed),
(u8 *)&phys_seed);
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -32,6 +32,13 @@

static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE;

+static int __section(.data) __nokaslr;
+
+int __pure nokaslr(void)
+{
+ return __nokaslr;
+}
+
/*
* Allow the platform to override the allocation granularity: this allows
* systems that have the capability to run with a larger page size to deal
@@ -351,17 +358,13 @@ void efi_free(efi_system_table_t *sys_ta
* environments, first in the early boot environment of the EFI boot
* stub, and subsequently during the kernel boot.
*/
-efi_status_t efi_parse_options(char *cmdline)
+efi_status_t efi_parse_options(char const *cmdline)
{
char *str;

- /*
- * Currently, the only efi= option we look for is 'nochunk', which
- * is intended to work around known issues on certain x86 UEFI
- * versions. So ignore for now on other architectures.
- */
- if (!IS_ENABLED(CONFIG_X86))
- return EFI_SUCCESS;
+ str = strstr(cmdline, "nokaslr");
+ if (str == cmdline || (str && str > cmdline && *(str - 1) == ' '))
+ __nokaslr = 1;

/*
* If no EFI parameters were specified on the cmdline we've got
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -15,6 +15,8 @@
*/
#undef __init

+extern int __pure nokaslr(void);
+
void efi_char16_printk(efi_system_table_t *, efi_char16_t *);

efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image,
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1427,7 +1427,7 @@ efi_status_t handle_cmdline_files(efi_sy
unsigned long *load_addr,
unsigned long *load_size);

-efi_status_t efi_parse_options(char *cmdline);
+efi_status_t efi_parse_options(char const *cmdline);

efi_status_t efi_setup_gop(efi_system_table_t *sys_table_arg,
struct screen_info *si, efi_guid_t *proto,