[GIT PULL] x86 fixes

Ingo Molnar
2016-02-20T11:30:39Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: f4eafd8bcd5229e998aa252627703b8462c3b90f x86/mm: Fix vmalloc_fault() to handle large pages properly

This is unusually large, partly due to the EFI fixes that prevent accidental
deletion of EFI variables through efivarfs that may brick machines. These fixes
are somewhat involved to maintain compatibility with existing install methods and
other usage modes, while trying to turn off the 'rm -rf' bricking vector.

Other fixes are for large page ioremap()s and for non-temporal user-memcpy()s.

out-of-topic modifications in x86-urgent-for-linus:
-----------------------------------------------------
drivers/char/hpet.c # 4e7f9df25874: hpet: Drop stale URLs
drivers/firmware/efi/efivars.c # 8282f5d9c17f: efi: Make our variable valid
# e0d64e6a880e: efi: Use ucs2_as_utf8 in efi
drivers/firmware/efi/vars.c # e246eb568bc4: efi: Add pstore variables to
# ed8b0de5a33d: efi: Make efivarfs entries i
# 8282f5d9c17f: efi: Make our variable valid
# 3dcb1f55dfc7: efi: Do variable name valida
fs/efivarfs/file.c # ed8b0de5a33d: efi: Make efivarfs entries i
fs/efivarfs/inode.c # ed8b0de5a33d: efi: Make efivarfs entries i
fs/efivarfs/internal.h # ed8b0de5a33d: efi: Make efivarfs entries i
fs/efivarfs/super.c # ed8b0de5a33d: efi: Make efivarfs entries i
# e0d64e6a880e: efi: Use ucs2_as_utf8 in efi
include/linux/ucs2_string.h # 73500267c930: lib/ucs2_string: Add ucs2 ->
lib/ucs2_string.c # a68075908a37: lib/ucs2_string: Correct ucs
# 73500267c930: lib/ucs2_string: Add ucs2 ->
tools/testing/selftests/efivarfs/efivarfs.sh# ed8b0de5a33d: efi: Make efivarfs entries i
tools/testing/selftests/efivarfs/open-unlink.c# ed8b0de5a33d: efi: Make efivarfs entries i

Thanks,

Ingo

------------------>
Jason Andryuk (1):
lib/ucs2_string: Correct ucs2 -> utf8 conversion

Matt Fleming (1):
efi: Add pstore variables to the deletion whitelist

Michael S. Tsirkin (1):
hpet: Drop stale URLs

Peter Jones (5):
lib/ucs2_string: Add ucs2 -> utf8 helper functions
efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version
efi: Do variable name validation tests in utf8
efi: Make our variable validation list include the guid
efi: Make efivarfs entries immutable by default

Toshi Kani (3):
x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
x86/mm: Fix vmalloc_fault() to handle large pages properly

Documentation/filesystems/efivarfs.txt | 7 ++
Documentation/timers/hpet.txt | 4 +-
arch/x86/Kconfig | 4 +-
arch/x86/lib/copy_user_64.S | 142 +++++++++++++++++-------
arch/x86/mm/fault.c | 15 ++-
drivers/char/hpet.c | 2 +-
drivers/firmware/efi/efivars.c | 35 +++---
drivers/firmware/efi/vars.c | 144 ++++++++++++++++++-------
fs/efivarfs/file.c | 70 ++++++++++++
fs/efivarfs/inode.c | 30 ++++--
fs/efivarfs/internal.h | 3 +-
fs/efivarfs/super.c | 16 +--
include/linux/efi.h | 5 +-
include/linux/ucs2_string.h | 4 +
lib/ucs2_string.c | 62 +++++++++++
tools/testing/selftests/efivarfs/efivarfs.sh | 19 +++-
tools/testing/selftests/efivarfs/open-unlink.c | 72 ++++++++++++-
17 files changed, 500 insertions(+), 134 deletions(-)

diff --git a/Documentation/filesystems/efivarfs.txt b/Documentation/filesystems/efivarfs.txt
index c477af086e65..686a64bba775 100644
--- a/Documentation/filesystems/efivarfs.txt
+++ b/Documentation/filesystems/efivarfs.txt
@@ -14,3 +14,10 @@ filesystem.
efivarfs is typically mounted like this,

mount -t efivarfs none /sys/firmware/efi/efivars
+
+Due to the presence of numerous firmware bugs where removing non-standard
+UEFI variables causes the system firmware to fail to POST, efivarfs
+files that are not well-known standardized variables are created
+as immutable files. This doesn't prevent removal - "chattr -i" will work -
+but it does prevent this kind of failure from being accomplished
+accidentally.
diff --git a/Documentation/timers/hpet.txt b/Documentation/timers/hpet.txt
index 767392ffd31e..a484d2c109d7 100644
--- a/Documentation/timers/hpet.txt
+++ b/Documentation/timers/hpet.txt
@@ -1,9 +1,7 @@
High Precision Event Timer Driver for Linux

The High Precision Event Timer (HPET) hardware follows a specification
-by Intel and Microsoft which can be found at
-
- http://www.intel.com/hardwaredesign/hpetspec_1.pdf
+by Intel and Microsoft, revision 1.

Each HPET has one fixed-rate counter (at 10+ MHz, hence "High Precision")
and up to 32 comparators. Normally three or more comparators are provided,
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ab2ed5328f0a..c46662f64c39 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -778,8 +778,8 @@ config HPET_TIMER
HPET is the next generation timer replacing legacy 8254s.
The HPET provides a stable time base on SMP
systems, unlike the TSC, but it is more expensive to access,
- as it is off-chip. You can find the HPET spec at
- <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
+ as it is off-chip. The interface used is documented
+ in the HPET spec, revision 1.

You can safely choose Y here. However, HPET will only be
activated if the platform and the BIOS support this feature.
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 982ce34f4a9b..27f89c79a44b 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -232,17 +232,31 @@ ENDPROC(copy_user_enhanced_fast_string)

/*
* copy_user_nocache - Uncached memory copy with exception handling
- * This will force destination/source out of cache for more performance.
+ * This will force destination out of cache for more performance.
+ *
+ * Note: Cached memory copy is used when destination or size is not
+ * naturally aligned. That is:
+ * - Require 8-byte alignment when size is 8 bytes or larger.
+ * - Require 4-byte alignment when size is 4 bytes.
*/
ENTRY(__copy_user_nocache)
ASM_STAC
+
+ /* If size is less than 8 bytes, go to 4-byte copy */
cmpl $8,%edx
- jb 20f /* less then 8 bytes, go to byte copy loop */
+ jb .L_4b_nocache_copy_entry
+
+ /* If destination is not 8-byte aligned, "cache" copy to align it */
ALIGN_DESTINATION
+
+ /* Set 4x8-byte copy count and remainder */
movl %edx,%ecx
andl $63,%edx
shrl $6,%ecx
- jz 17f
+ jz .L_8b_nocache_copy_entry /* jump if count is 0 */
+
+ /* Perform 4x8-byte nocache loop-copy */
+.L_4x8b_nocache_copy_loop:
1: movq (%rsi),%r8
2: movq 1*8(%rsi),%r9
3: movq 2*8(%rsi),%r10
@@ -262,60 +276,106 @@ ENTRY(__copy_user_nocache)
leaq 64(%rsi),%rsi
leaq 64(%rdi),%rdi
decl %ecx
- jnz 1b
-17: movl %edx,%ecx
+ jnz .L_4x8b_nocache_copy_loop
+
+ /* Set 8-byte copy count and remainder */
+.L_8b_nocache_copy_entry:
+ movl %edx,%ecx
andl $7,%edx
shrl $3,%ecx
- jz 20f
-18: movq (%rsi),%r8
-19: movnti %r8,(%rdi)
+ jz .L_4b_nocache_copy_entry /* jump if count is 0 */
+
+ /* Perform 8-byte nocache loop-copy */
+.L_8b_nocache_copy_loop:
+20: movq (%rsi),%r8
+21: movnti %r8,(%rdi)
leaq 8(%rsi),%rsi
leaq 8(%rdi),%rdi
decl %ecx
- jnz 18b
-20: andl %edx,%edx
- jz 23f
+ jnz .L_8b_nocache_copy_loop
+
+ /* If no byte left, we're done */
+.L_4b_nocache_copy_entry:
+ andl %edx,%edx
+ jz .L_finish_copy
+
+ /* If destination is not 4-byte aligned, go to byte copy: */
+ movl %edi,%ecx
+ andl $3,%ecx
+ jnz .L_1b_cache_copy_entry
+
+ /* Set 4-byte copy count (1 or 0) and remainder */
movl %edx,%ecx
-21: movb (%rsi),%al
-22: movb %al,(%rdi)
+ andl $3,%edx
+ shrl $2,%ecx
+ jz .L_1b_cache_copy_entry /* jump if count is 0 */
+
+ /* Perform 4-byte nocache copy: */
+30: movl (%rsi),%r8d
+31: movnti %r8d,(%rdi)
+ leaq 4(%rsi),%rsi
+ leaq 4(%rdi),%rdi
+
+ /* If no bytes left, we're done: */
+ andl %edx,%edx
+ jz .L_finish_copy
+
+ /* Perform byte "cache" loop-copy for the remainder */
+.L_1b_cache_copy_entry:
+ movl %edx,%ecx
+.L_1b_cache_copy_loop:
+40: movb (%rsi),%al
+41: movb %al,(%rdi)
incq %rsi
incq %rdi
decl %ecx
- jnz 21b
-23: xorl %eax,%eax
+ jnz .L_1b_cache_copy_loop
+
+ /* Finished copying; fence the prior stores */
+.L_finish_copy:
+ xorl %eax,%eax
ASM_CLAC
sfence
ret

.section .fixup,"ax"
-30: shll $6,%ecx
+.L_fixup_4x8b_copy:
+ shll $6,%ecx
addl %ecx,%edx
- jmp 60f
-40: lea (%rdx,%rcx,8),%rdx
- jmp 60f
-50: movl %ecx,%edx
-60: sfence
+ jmp .L_fixup_handle_tail
+.L_fixup_8b_copy:
+ lea (%rdx,%rcx,8),%rdx
+ jmp .L_fixup_handle_tail
+.L_fixup_4b_copy:
+ lea (%rdx,%rcx,4),%rdx
+ jmp .L_fixup_handle_tail
+.L_fixup_1b_copy:
+ movl %ecx,%edx
+.L_fixup_handle_tail:
+ sfence
jmp copy_user_handle_tail
.previous

- _ASM_EXTABLE(1b,30b)
- _ASM_EXTABLE(2b,30b)
- _ASM_EXTABLE(3b,30b)
- _ASM_EXTABLE(4b,30b)
- _ASM_EXTABLE(5b,30b)
- _ASM_EXTABLE(6b,30b)
- _ASM_EXTABLE(7b,30b)
- _ASM_EXTABLE(8b,30b)
- _ASM_EXTABLE(9b,30b)
- _ASM_EXTABLE(10b,30b)
- _ASM_EXTABLE(11b,30b)
- _ASM_EXTABLE(12b,30b)
- _ASM_EXTABLE(13b,30b)
- _ASM_EXTABLE(14b,30b)
- _ASM_EXTABLE(15b,30b)
- _ASM_EXTABLE(16b,30b)
- _ASM_EXTABLE(18b,40b)
- _ASM_EXTABLE(19b,40b)
- _ASM_EXTABLE(21b,50b)
- _ASM_EXTABLE(22b,50b)
+ _ASM_EXTABLE(1b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(2b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(3b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(4b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(5b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(6b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(7b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(8b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(9b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(10b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(11b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(12b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(13b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(14b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(15b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(16b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(20b,.L_fixup_8b_copy)
+ _ASM_EXTABLE(21b,.L_fixup_8b_copy)
+ _ASM_EXTABLE(30b,.L_fixup_4b_copy)
+ _ASM_EXTABLE(31b,.L_fixup_4b_copy)
+ _ASM_EXTABLE(40b,.L_fixup_1b_copy)
+ _ASM_EXTABLE(41b,.L_fixup_1b_copy)
ENDPROC(__copy_user_nocache)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index eef44d9a3f77..e830c71a1323 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -287,6 +287,9 @@ static noinline int vmalloc_fault(unsigned long address)
if (!pmd_k)
return -1;

+ if (pmd_huge(*pmd_k))
+ return 0;
+
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
return -1;
@@ -360,8 +363,6 @@ void vmalloc_sync_all(void)
* 64-bit:
*
* Handle a fault on the vmalloc area
- *
- * This assumes no large pages in there.
*/
static noinline int vmalloc_fault(unsigned long address)
{
@@ -403,17 +404,23 @@ static noinline int vmalloc_fault(unsigned long address)
if (pud_none(*pud_ref))
return -1;

- if (pud_none(*pud) || pud_page_vaddr(*pud) != pud_page_vaddr(*pud_ref))
+ if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref))
BUG();

+ if (pud_huge(*pud))
+ return 0;
+
pmd = pmd_offset(pud, address);
pmd_ref = pmd_offset(pud_ref, address);
if (pmd_none(*pmd_ref))
return -1;

- if (pmd_none(*pmd) || pmd_page(*pmd) != pmd_page(*pmd_ref))
+ if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref))
BUG();

+ if (pmd_huge(*pmd))
+ return 0;
+
pte_ref = pte_offset_kernel(pmd_ref, address);
if (!pte_present(*pte_ref))
return -1;
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 240b6cf1d97c..be54e5331a45 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -42,7 +42,7 @@
/*
* The High Precision Event Timer driver.
* This driver is closely modelled after the rtc.c driver.
- * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
+ * See HPET spec revision 1.
*/
#define HPET_USER_FREQ (64)
#define HPET_DRIFT (500)
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 756eca8c4cf8..10e6774ab2a2 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -221,7 +221,7 @@ sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor,
}

if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
- efivar_validate(name, data, size) == false) {
+ efivar_validate(vendor, name, data, size) == false) {
printk(KERN_ERR "efivars: Malformed variable content\n");
return -EINVAL;
}
@@ -447,7 +447,8 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
}

if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
- efivar_validate(name, data, size) == false) {
+ efivar_validate(new_var->VendorGuid, name, data,
+ size) == false) {
printk(KERN_ERR "efivars: Malformed variable content\n");
return -EINVAL;
}
@@ -540,38 +541,30 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
static int
efivar_create_sysfs_entry(struct efivar_entry *new_var)
{
- int i, short_name_size;
+ int short_name_size;
char *short_name;
- unsigned long variable_name_size;
- efi_char16_t *variable_name;
+ unsigned long utf8_name_size;
+ efi_char16_t *variable_name = new_var->var.VariableName;
int ret;

- variable_name = new_var->var.VariableName;
- variable_name_size = ucs2_strlen(variable_name) * sizeof(efi_char16_t);
-
/*
- * Length of the variable bytes in ASCII, plus the '-' separator,
+ * Length of the variable bytes in UTF8, plus the '-' separator,
* plus the GUID, plus trailing NUL
*/
- short_name_size = variable_name_size / sizeof(efi_char16_t)
- + 1 + EFI_VARIABLE_GUID_LEN + 1;
-
- short_name = kzalloc(short_name_size, GFP_KERNEL);
+ utf8_name_size = ucs2_utf8size(variable_name);
+ short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1;

+ short_name = kmalloc(short_name_size, GFP_KERNEL);
if (!short_name)
return -ENOMEM;

- /* Convert Unicode to normal chars (assume top bits are 0),
- ala UTF-8 */
- for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
- short_name[i] = variable_name[i] & 0xFF;
- }
+ ucs2_as_utf8(short_name, variable_name, short_name_size);
+
/* This is ugly, but necessary to separate one vendor's
private variables from another's. */
-
- *(short_name + strlen(short_name)) = '-';
+ short_name[utf8_name_size] = '-';
efi_guid_to_str(&new_var->var.VendorGuid,
- short_name + strlen(short_name));
+ short_name + utf8_name_size + 1);

new_var->kobj.kset = efivars_kset;

diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 70a0fb10517f..7f2ea21c730d 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -165,67 +165,133 @@ validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer,
}

struct variable_validate {
+ efi_guid_t vendor;
char *name;
bool (*validate)(efi_char16_t *var_name, int match, u8 *data,
unsigned long len);
};

+/*
+ * This is the list of variables we need to validate, as well as the
+ * whitelist for what we think is safe not to default to immutable.
+ *
+ * If it has a validate() method that's not NULL, it'll go into the
+ * validation routine. If not, it is assumed valid, but still used for
+ * whitelisting.
+ *
+ * Note that it's sorted by {vendor,name}, but globbed names must come after
+ * any other name with the same prefix.
+ */
static const struct variable_validate variable_validate[] = {
- { "BootNext", validate_uint16 },
- { "BootOrder", validate_boot_order },
- { "DriverOrder", validate_boot_order },
- { "Boot*", validate_load_option },
- { "Driver*", validate_load_option },
- { "ConIn", validate_device_path },
- { "ConInDev", validate_device_path },
- { "ConOut", validate_device_path },
- { "ConOutDev", validate_device_path },
- { "ErrOut", validate_device_path },
- { "ErrOutDev", validate_device_path },
- { "Timeout", validate_uint16 },
- { "Lang", validate_ascii_string },
- { "PlatformLang", validate_ascii_string },
- { "", NULL },
+ { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 },
+ { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order },
+ { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option },
+ { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order },
+ { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string },
+ { EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL },
+ { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string },
+ { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 },
+ { LINUX_EFI_CRASH_GUID, "*", NULL },
+ { NULL_GUID, "", NULL },
};

+static bool
+variable_matches(const char *var_name, size_t len, const char *match_name,
+ int *match)
+{
+ for (*match = 0; ; (*match)++) {
+ char c = match_name[*match];
+ char u = var_name[*match];
+
+ /* Wildcard in the matching name means we've matched */
+ if (c == '*')
+ return true;
+
+ /* Case sensitive match */
+ if (!c && *match == len)
+ return true;
+
+ if (c != u)
+ return false;
+
+ if (!c)
+ return true;
+ }
+ return true;
+}
+
bool
-efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len)
+efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
+ unsigned long data_size)
{
int i;
- u16 *unicode_name = var_name;
+ unsigned long utf8_size;
+ u8 *utf8_name;

- for (i = 0; variable_validate[i].validate != NULL; i++) {
- const char *name = variable_validate[i].name;
- int match;
+ utf8_size = ucs2_utf8size(var_name);
+ utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL);
+ if (!utf8_name)
+ return false;

- for (match = 0; ; match++) {
- char c = name[match];
- u16 u = unicode_name[match];
+ ucs2_as_utf8(utf8_name, var_name, utf8_size);
+ utf8_name[utf8_size] = '\0';

- /* All special variables are plain ascii */
- if (u > 127)
- return true;
+ for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
+ const char *name = variable_validate[i].name;
+ int match = 0;

- /* Wildcard in the matching name means we've matched */
- if (c == '*')
- return variable_validate[i].validate(var_name,
- match, data, len);
+ if (efi_guidcmp(vendor, variable_validate[i].vendor))
+ continue;

- /* Case sensitive match */
- if (c != u)
+ if (variable_matches(utf8_name, utf8_size+1, name, &match)) {
+ if (variable_validate[i].validate == NULL)
break;
-
- /* Reached the end of the string while matching */
- if (!c)
- return variable_validate[i].validate(var_name,
- match, data, len);
+ kfree(utf8_name);
+ return variable_validate[i].validate(var_name, match,
+ data, data_size);
}
}
-
+ kfree(utf8_name);
return true;
}
EXPORT_SYMBOL_GPL(efivar_validate);

+bool
+efivar_variable_is_removable(efi_guid_t vendor, const char *var_name,
+ size_t len)
+{
+ int i;
+ bool found = false;
+ int match = 0;
+
+ /*
+ * Check if our variable is in the validated variables list
+ */
+ for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
+ if (efi_guidcmp(variable_validate[i].vendor, vendor))
+ continue;
+
+ if (variable_matches(var_name, len,
+ variable_validate[i].name, &match)) {
+ found = true;
+ break;
+ }
+ }
+
+ /*
+ * If it's in our list, it is removable.
+ */
+ return found;
+}
+EXPORT_SYMBOL_GPL(efivar_variable_is_removable);
+
static efi_status_t
check_var_size(u32 attributes, unsigned long size)
{
@@ -852,7 +918,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,

*set = false;

- if (efivar_validate(name, data, *size) == false)
+ if (efivar_validate(*vendor, name, data, *size) == false)
return -EINVAL;

/*
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index c424e4813ec8..d48e0d261d78 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -10,6 +10,7 @@
#include <linux/efi.h>
#include <linux/fs.h>
#include <linux/slab.h>
+#include <linux/mount.h>

#include "internal.h"

@@ -103,9 +104,78 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
return size;
}

+static int
+efivarfs_ioc_getxflags(struct file *file, void __user *arg)
+{
+ struct inode *inode = file->f_mapping->host;
+ unsigned int i_flags;
+ unsigned int flags = 0;
+
+ i_flags = inode->i_flags;
+ if (i_flags & S_IMMUTABLE)
+ flags |= FS_IMMUTABLE_FL;
+
+ if (copy_to_user(arg, &flags, sizeof(flags)))
+ return -EFAULT;
+ return 0;
+}
+
+static int
+efivarfs_ioc_setxflags(struct file *file, void __user *arg)
+{
+ struct inode *inode = file->f_mapping->host;
+ unsigned int flags;
+ unsigned int i_flags = 0;
+ int error;
+
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
+ if (copy_from_user(&flags, arg, sizeof(flags)))
+ return -EFAULT;
+
+ if (flags & ~FS_IMMUTABLE_FL)
+ return -EOPNOTSUPP;
+
+ if (!capable(CAP_LINUX_IMMUTABLE))
+ return -EPERM;
+
+ if (flags & FS_IMMUTABLE_FL)
+ i_flags |= S_IMMUTABLE;
+
+
+ error = mnt_want_write_file(file);
+ if (error)
+ return error;
+
+ inode_lock(inode);
+ inode_set_flags(inode, i_flags, S_IMMUTABLE);
+ inode_unlock(inode);
+
+ mnt_drop_write_file(file);
+
+ return 0;
+}
+
+long
+efivarfs_file_ioctl(struct file *file, unsigned int cmd, unsigned long p)
+{
+ void __user *arg = (void __user *)p;
+
+ switch (cmd) {
+ case FS_IOC_GETFLAGS:
+ return efivarfs_ioc_getxflags(file, arg);
+ case FS_IOC_SETFLAGS:
+ return efivarfs_ioc_setxflags(file, arg);
+ }
+
+ return -ENOTTY;
+}
+
const struct file_operations efivarfs_file_operations = {
.open = simple_open,
.read = efivarfs_file_read,
.write = efivarfs_file_write,
.llseek = no_llseek,
+ .unlocked_ioctl = efivarfs_file_ioctl,
};
diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c
index 3381b9da9ee6..e2ab6d0497f2 100644
--- a/fs/efivarfs/inode.c
+++ b/fs/efivarfs/inode.c
@@ -15,7 +15,8 @@
#include "internal.h"

struct inode *efivarfs_get_inode(struct super_block *sb,
- const struct inode *dir, int mode, dev_t dev)
+ const struct inode *dir, int mode,
+ dev_t dev, bool is_removable)
{
struct inode *inode = new_inode(sb);

@@ -23,6 +24,7 @@ struct inode *efivarfs_get_inode(struct super_block *sb,
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_flags = is_removable ? 0 : S_IMMUTABLE;
switch (mode & S_IFMT) {
case S_IFREG:
inode->i_fop = &efivarfs_file_operations;
@@ -102,22 +104,17 @@ static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
static int efivarfs_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool excl)
{
- struct inode *inode;
+ struct inode *inode = NULL;
struct efivar_entry *var;
int namelen, i = 0, err = 0;
+ bool is_removable = false;

if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
return -EINVAL;

- inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
- if (!inode)
- return -ENOMEM;
-
var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
- if (!var) {
- err = -ENOMEM;
- goto out;
- }
+ if (!var)
+ return -ENOMEM;

/* length of the variable name itself: remove GUID and separator */
namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
@@ -125,6 +122,16 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry,
efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
&var->var.VendorGuid);

+ if (efivar_variable_is_removable(var->var.VendorGuid,
+ dentry->d_name.name, namelen))
+ is_removable = true;
+
+ inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0, is_removable);
+ if (!inode) {
+ err = -ENOMEM;
+ goto out;
+ }
+
for (i = 0; i < namelen; i++)
var->var.VariableName[i] = dentry->d_name.name[i];

@@ -138,7 +145,8 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry,
out:
if (err) {
kfree(var);
- iput(inode);
+ if (inode)
+ iput(inode);
}
return err;
}
diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
index b5ff16addb7c..b4505188e799 100644
--- a/fs/efivarfs/internal.h
+++ b/fs/efivarfs/internal.h
@@ -15,7 +15,8 @@ extern const struct file_operations efivarfs_file_operations;
extern const struct inode_operations efivarfs_dir_inode_operations;
extern bool efivarfs_valid_name(const char *str, int len);
extern struct inode *efivarfs_get_inode(struct super_block *sb,
- const struct inode *dir, int mode, dev_t dev);
+ const struct inode *dir, int mode, dev_t dev,
+ bool is_removable);

extern struct list_head efivarfs_list;

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index b8a564f29107..dd029d13ea61 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -118,8 +118,9 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
struct dentry *dentry, *root = sb->s_root;
unsigned long size = 0;
char *name;
- int len, i;
+ int len;
int err = -ENOMEM;
+ bool is_removable = false;

entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
@@ -128,15 +129,17 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
memcpy(entry->var.VariableName, name16, name_size);
memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));

- len = ucs2_strlen(entry->var.VariableName);
+ len = ucs2_utf8size(entry->var.VariableName);

/* name, plus '-', plus GUID, plus NUL*/
name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
if (!name)
goto fail;

- for (i = 0; i < len; i++)
- name[i] = entry->var.VariableName[i] & 0xFF;
+ ucs2_as_utf8(name, entry->var.VariableName, len);
+
+ if (efivar_variable_is_removable(entry->var.VendorGuid, name, len))
+ is_removable = true;

name[len] = '-';

@@ -144,7 +147,8 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,

name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';

- inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0);
+ inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0,
+ is_removable);
if (!inode)
goto fail_name;

@@ -200,7 +204,7 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_d_op = &efivarfs_d_ops;
sb->s_time_gran = 1;

- inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0);
+ inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0, true);
if (!inode)
return -ENOMEM;
inode->i_op = &efivarfs_dir_inode_operations;
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 569b5a866bb1..47be3ad7d3e5 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1199,7 +1199,10 @@ int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
struct list_head *head, bool remove);

-bool efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len);
+bool efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
+ unsigned long data_size);
+bool efivar_variable_is_removable(efi_guid_t vendor, const char *name,
+ size_t len);

extern struct work_struct efivar_work;
void efivar_run_worker(void);
diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h
index cbb20afdbc01..bb679b48f408 100644
--- a/include/linux/ucs2_string.h
+++ b/include/linux/ucs2_string.h
@@ -11,4 +11,8 @@ unsigned long ucs2_strlen(const ucs2_char_t *s);
unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength);
int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len);

+unsigned long ucs2_utf8size(const ucs2_char_t *src);
+unsigned long ucs2_as_utf8(u8 *dest, const ucs2_char_t *src,
+ unsigned long maxlength);
+
#endif /* _LINUX_UCS2_STRING_H_ */
diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c
index 6f500ef2301d..f0b323abb4c6 100644
--- a/lib/ucs2_string.c
+++ b/lib/ucs2_string.c
@@ -49,3 +49,65 @@ ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
}
}
EXPORT_SYMBOL(ucs2_strncmp);
+
+unsigned long
+ucs2_utf8size(const ucs2_char_t *src)
+{
+ unsigned long i;
+ unsigned long j = 0;
+
+ for (i = 0; i < ucs2_strlen(src); i++) {
+ u16 c = src[i];
+
+ if (c >= 0x800)
+ j += 3;
+ else if (c >= 0x80)
+ j += 2;
+ else
+ j += 1;
+ }
+
+ return j;
+}
+EXPORT_SYMBOL(ucs2_utf8size);
+
+/*
+ * copy at most maxlength bytes of whole utf8 characters to dest from the
+ * ucs2 string src.
+ *
+ * The return value is the number of characters copied, not including the
+ * final NUL character.
+ */
+unsigned long
+ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
+{
+ unsigned int i;
+ unsigned long j = 0;
+ unsigned long limit = ucs2_strnlen(src, maxlength);
+
+ for (i = 0; maxlength && i < limit; i++) {
+ u16 c = src[i];
+
+ if (c >= 0x800) {
+ if (maxlength < 3)
+ break;
+ maxlength -= 3;
+ dest[j++] = 0xe0 | (c & 0xf000) >> 12;
+ dest[j++] = 0x80 | (c & 0x0fc0) >> 6;
+ dest[j++] = 0x80 | (c & 0x003f);
+ } else if (c >= 0x80) {
+ if (maxlength < 2)
+ break;
+ maxlength -= 2;
+ dest[j++] = 0xc0 | (c & 0x7c0) >> 6;
+ dest[j++] = 0x80 | (c & 0x03f);
+ } else {
+ maxlength -= 1;
+ dest[j++] = c & 0x7f;
+ }
+ }
+ if (maxlength)
+ dest[j] = '\0';
+ return j;
+}
+EXPORT_SYMBOL(ucs2_as_utf8);
diff --git a/tools/testing/selftests/efivarfs/efivarfs.sh b/tools/testing/selftests/efivarfs/efivarfs.sh
index 77edcdcc016b..057278448515 100755
--- a/tools/testing/selftests/efivarfs/efivarfs.sh
+++ b/tools/testing/selftests/efivarfs/efivarfs.sh
@@ -88,7 +88,11 @@ test_delete()
exit 1
fi

- rm $file
+ rm $file 2>/dev/null
+ if [ $? -ne 0 ]; then
+ chattr -i $file
+ rm $file
+ fi

if [ -e $file ]; then
echo "$file couldn't be deleted" >&2
@@ -111,6 +115,7 @@ test_zero_size_delete()
exit 1
fi

+ chattr -i $file
printf "$attrs" > $file

if [ -e $file ]; then
@@ -141,7 +146,11 @@ test_valid_filenames()
echo "$file could not be created" >&2
ret=1
else
- rm $file
+ rm $file 2>/dev/null
+ if [ $? -ne 0 ]; then
+ chattr -i $file
+ rm $file
+ fi
fi
done

@@ -174,7 +183,11 @@ test_invalid_filenames()

if [ -e $file ]; then
echo "Creating $file should have failed" >&2
- rm $file
+ rm $file 2>/dev/null
+ if [ $? -ne 0 ]; then
+ chattr -i $file
+ rm $file
+ fi
ret=1
fi
done
diff --git a/tools/testing/selftests/efivarfs/open-unlink.c b/tools/testing/selftests/efivarfs/open-unlink.c
index 8c0764407b3c..4af74f733036 100644
--- a/tools/testing/selftests/efivarfs/open-unlink.c
+++ b/tools/testing/selftests/efivarfs/open-unlink.c
@@ -1,10 +1,68 @@
+#include <errno.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
+#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
+#include <linux/fs.h>
+
+static int set_immutable(const char *path, int immutable)
+{
+ unsigned int flags;
+ int fd;
+ int rc;
+ int error;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return fd;
+
+ rc = ioctl(fd, FS_IOC_GETFLAGS, &flags);
+ if (rc < 0) {
+ error = errno;
+ close(fd);
+ errno = error;
+ return rc;
+ }
+
+ if (immutable)
+ flags |= FS_IMMUTABLE_FL;
+ else
+ flags &= ~FS_IMMUTABLE_FL;
+
+ rc = ioctl(fd, FS_IOC_SETFLAGS, &flags);
+ error = errno;
+ close(fd);
+ errno = error;
+ return rc;
+}
+
+static int get_immutable(const char *path)
+{
+ unsigned int flags;
+ int fd;
+ int rc;
+ int error;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return fd;
+
+ rc = ioctl(fd, FS_IOC_GETFLAGS, &flags);
+ if (rc < 0) {
+ error = errno;
+ close(fd);
+ errno = error;
+ return rc;
+ }
+ close(fd);
+ if (flags & FS_IMMUTABLE_FL)
+ return 1;
+ return 0;
+}

int main(int argc, char **argv)
{
@@ -27,7 +85,7 @@ int main(int argc, char **argv)
buf[4] = 0;

/* create a test variable */
- fd = open(path, O_WRONLY | O_CREAT);
+ fd = open(path, O_WRONLY | O_CREAT, 0600);
if (fd < 0) {
perror("open(O_WRONLY)");
return EXIT_FAILURE;
@@ -41,6 +99,18 @@ int main(int argc, char **argv)

close(fd);

+ rc = get_immutable(path);
+ if (rc < 0) {
+ perror("ioctl(FS_IOC_GETFLAGS)");
+ return EXIT_FAILURE;
+ } else if (rc) {
+ rc = set_immutable(path, 0);
+ if (rc < 0) {
+ perror("ioctl(FS_IOC_SETFLAGS)");
+ return EXIT_FAILURE;
+ }
+ }
+
fd = open(path, O_RDONLY);
if (fd < 0) {
perror("open");