[tip:efi/core] efi/libstub: Unify command line param parsing

tip-bot for Ard Biesheuvel
2017-04-05T10:43:25Z

Commit-ID: 60f38de7a8d4e816100ceafd1b382df52527bd50
Gitweb: http://git.kernel.org/tip/60f38de7a8d4e816100ceafd1b382df52527bd50
Author: Ard Biesheuvel <ard.biesheuvel@linaro.org>
AuthorDate: Tue, 4 Apr 2017 17:09:08 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 5 Apr 2017 12:27:28 +0200

efi/libstub: Unify command line param parsing

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@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Cc: bhsharma@redhat.com
Cc: bp@alien8.de
Cc: eugene@hp.com
Cc: evgeny.kalugin@intel.com
Cc: jhugo@codeaurora.org
Cc: leif.lindholm@linaro.org
Cc: linux-efi@vger.kernel.org
Cc: mark.rutland@arm.com
Cc: roy.franz@cavium.com
Cc: rruigrok@codeaurora.org
Link: http://lkml.kernel.org/r/20170404160910.28115-1-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
drivers/firmware/efi/libstub/arm-stub.c | 24 +++++++-----------------
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(+), 29 deletions(-)

diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 02049ff..ac3222f 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -18,8 +18,6 @@

#include "efistub.h"

-bool __nokaslr;
-
efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
void *__image, void **__fh)
{
@@ -153,18 +151,6 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
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,
@@ -176,9 +162,13 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
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);

diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index eae693e..b4c2589 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -16,8 +16,6 @@

#include "efistub.h"

-extern bool __nokaslr;
-
efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
{
u64 tg;
@@ -52,7 +50,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
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);
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 3290fae..2e17d2b 100644
--- 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;
+}
+
#define EFI_MMAP_NR_SLACK_SLOTS 8

struct file_info {
@@ -409,17 +416,13 @@ static efi_status_t efi_file_close(void *handle)
* 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
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 71c4d0e..a7a2a2c 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -24,6 +24,8 @@
#define EFI_ALLOC_ALIGN EFI_PAGE_SIZE
#endif

+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,
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 94d34e0..e485e87 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1471,7 +1471,7 @@ efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
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,