[kernel] r19937 - in dists/sid/linux/debian: . config/ia64 config/kernelarch-x86 patches patches/bugfix/all
Ben Hutchings
benh at alioth.debian.org
Fri Mar 22 20:15:10 UTC 2013
Author: benh
Date: Fri Mar 22 20:15:09 2013
New Revision: 19937
Log:
efivars: Work around serious firmware bugs
- Allow disabling use as a pstore backend
- Add module parameter to disable use as a pstore backend
* [x86] Set EFI_VARS_PSTORE_DEFAULT_DISABLE=y
- explicitly calculate length of VariableName
- Handle duplicate names from get_next_variable()
Also apply another fix entangled with them:
- efi_pstore: Introducing workqueue updating sysfs
Added:
dists/sid/linux/debian/patches/bugfix/all/efi_pstore-Introducing-workqueue-updating-sysfs.patch
dists/sid/linux/debian/patches/bugfix/all/efivars-Add-module-parameter-to-disable-use-as-a-pst.patch
dists/sid/linux/debian/patches/bugfix/all/efivars-Allow-disabling-use-as-a-pstore-backend.patch
dists/sid/linux/debian/patches/bugfix/all/efivars-Fix-check-for-CONFIG_EFI_VARS_PSTORE_DEFAULT.patch
dists/sid/linux/debian/patches/bugfix/all/efivars-Handle-duplicate-names-from-get_next_variabl.patch
dists/sid/linux/debian/patches/bugfix/all/efivars-explicitly-calculate-length-of-VariableName.patch
Modified:
dists/sid/linux/debian/changelog
dists/sid/linux/debian/config/ia64/config
dists/sid/linux/debian/config/kernelarch-x86/config
dists/sid/linux/debian/patches/series
Modified: dists/sid/linux/debian/changelog
==============================================================================
--- dists/sid/linux/debian/changelog Fri Mar 22 18:24:45 2013 (r19936)
+++ dists/sid/linux/debian/changelog Fri Mar 22 20:15:09 2013 (r19937)
@@ -96,6 +96,13 @@
* efi: Ensure efivars is loaded on EFI systems (Closes: #703363)
- [x86] Use a platform device to trigger loading of efivars
- [ia64] Change EFI_VARS from module to built-in
+ * efivars: Work around serious firmware bugs
+ - Allow disabling use as a pstore backend
+ - Add module parameter to disable use as a pstore backend
+ * [x86] Set EFI_VARS_PSTORE_DEFAULT_DISABLE=y
+ - explicitly calculate length of VariableName
+ - Handle duplicate names from get_next_variable()
+ * efi_pstore: Introducing workqueue updating sysfs
* kmsg_dump: Only dump kernel log in error cases (Closes: #703386)
- kexec: remove KMSG_DUMP_KEXEC
- kmsg_dump: don't run on non-error paths by default
@@ -118,7 +125,7 @@
module, as we now have a real fix for #701784
* [rt] Update to 3.2.40-rt60
- -- Ben Hutchings <ben at decadent.org.uk> Fri, 22 Mar 2013 18:24:24 +0000
+ -- Ben Hutchings <ben at decadent.org.uk> Fri, 22 Mar 2013 19:38:42 +0000
linux (3.2.39-2) unstable; urgency=high
Modified: dists/sid/linux/debian/config/ia64/config
==============================================================================
--- dists/sid/linux/debian/config/ia64/config Fri Mar 22 18:24:45 2013 (r19936)
+++ dists/sid/linux/debian/config/ia64/config Fri Mar 22 20:15:09 2013 (r19937)
@@ -132,6 +132,7 @@
## file: drivers/firmware/Kconfig
##
CONFIG_EFI_VARS=y
+CONFIG_EFI_VARS_PSTORE=y
CONFIG_DMIID=y
##
Modified: dists/sid/linux/debian/config/kernelarch-x86/config
==============================================================================
--- dists/sid/linux/debian/config/kernelarch-x86/config Fri Mar 22 18:24:45 2013 (r19936)
+++ dists/sid/linux/debian/config/kernelarch-x86/config Fri Mar 22 20:15:09 2013 (r19937)
@@ -384,6 +384,9 @@
CONFIG_EDD=m
# CONFIG_EDD_OFF is not set
CONFIG_EFI_VARS=m
+CONFIG_EFI_VARS_PSTORE=y
+#. Runtime-disabled by default
+CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE=y
CONFIG_DELL_RBU=m
CONFIG_DCDBAS=m
CONFIG_DMIID=y
Added: dists/sid/linux/debian/patches/bugfix/all/efi_pstore-Introducing-workqueue-updating-sysfs.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/efi_pstore-Introducing-workqueue-updating-sysfs.patch Fri Mar 22 20:15:09 2013 (r19937)
@@ -0,0 +1,176 @@
+From: Seiji Aguchi <seiji.aguchi at hds.com>
+Date: Tue, 12 Feb 2013 13:04:41 -0800
+Subject: efi_pstore: Introducing workqueue updating sysfs
+
+commit a93bc0c6e07ed9bac44700280e65e2945d864fd4 upstream.
+
+[Problem]
+efi_pstore creates sysfs entries, which enable users to access to NVRAM,
+in a write callback. If a kernel panic happens in an interrupt context,
+it may fail because it could sleep due to dynamic memory allocations during
+creating sysfs entries.
+
+[Patch Description]
+This patch removes sysfs operations from a write callback by introducing
+a workqueue updating sysfs entries which is scheduled after the write
+callback is called.
+
+Also, the workqueue is kicked in a just oops case.
+A system will go down in other cases such as panic, clean shutdown and emergency
+restart. And we don't need to create sysfs entries because there is no chance for
+users to access to them.
+
+efi_pstore will be robust against a kernel panic in an interrupt context with this patch.
+
+Signed-off-by: Seiji Aguchi <seiji.aguchi at hds.com>
+Acked-by: Matt Fleming <matt.fleming at intel.com>
+Signed-off-by: Tony Luck <tony.luck at intel.com>
+[bwh: Backported to 3.2:
+ - Adjust contest
+ - Don't check reason in efi_pstore_write(), as it is not given as a
+ parameter
+ - Move up declaration of __efivars]
+---
+--- a/drivers/firmware/efivars.c
++++ b/drivers/firmware/efivars.c
+@@ -128,6 +128,8 @@ struct efivar_attribute {
+ ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
+ };
+
++static struct efivars __efivars;
++
+ #define PSTORE_EFI_ATTRIBUTES \
+ (EFI_VARIABLE_NON_VOLATILE | \
+ EFI_VARIABLE_BOOTSERVICE_ACCESS | \
+@@ -152,6 +154,13 @@ efivar_create_sysfs_entry(struct efivars
+ efi_char16_t *variable_name,
+ efi_guid_t *vendor_guid);
+
++/*
++ * Prototype for workqueue functions updating sysfs entry
++ */
++
++static void efivar_update_sysfs_entries(struct work_struct *);
++static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
++
+ /* Return the number of unicode characters in data */
+ static unsigned long
+ utf16_strnlen(efi_char16_t *s, size_t maxlength)
+@@ -834,11 +843,7 @@ static int efi_pstore_write(enum pstore_
+ if (found)
+ efivar_unregister(found);
+
+- if (size)
+- ret = efivar_create_sysfs_entry(efivars,
+- utf16_strsize(efi_name,
+- DUMP_NAME_LEN * 2),
+- efi_name, &vendor);
++ schedule_work(&efivar_work);
+
+ *id = part;
+ return ret;
+@@ -1017,6 +1022,75 @@ static ssize_t efivar_delete(struct file
+ return count;
+ }
+
++static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
++{
++ struct efivar_entry *entry, *n;
++ struct efivars *efivars = &__efivars;
++ unsigned long strsize1, strsize2;
++ bool found = false;
++
++ strsize1 = utf16_strsize(variable_name, 1024);
++ list_for_each_entry_safe(entry, n, &efivars->list, list) {
++ strsize2 = utf16_strsize(entry->var.VariableName, 1024);
++ if (strsize1 == strsize2 &&
++ !memcmp(variable_name, &(entry->var.VariableName),
++ strsize2) &&
++ !efi_guidcmp(entry->var.VendorGuid,
++ *vendor)) {
++ found = true;
++ break;
++ }
++ }
++ return found;
++}
++
++static void efivar_update_sysfs_entries(struct work_struct *work)
++{
++ struct efivars *efivars = &__efivars;
++ efi_guid_t vendor;
++ efi_char16_t *variable_name;
++ unsigned long variable_name_size = 1024;
++ efi_status_t status = EFI_NOT_FOUND;
++ bool found;
++
++ /* Add new sysfs entries */
++ while (1) {
++ variable_name = kzalloc(variable_name_size, GFP_KERNEL);
++ if (!variable_name) {
++ pr_err("efivars: Memory allocation failed.\n");
++ return;
++ }
++
++ spin_lock_irq(&efivars->lock);
++ found = false;
++ while (1) {
++ variable_name_size = 1024;
++ status = efivars->ops->get_next_variable(
++ &variable_name_size,
++ variable_name,
++ &vendor);
++ if (status != EFI_SUCCESS) {
++ break;
++ } else {
++ if (!variable_is_present(variable_name,
++ &vendor)) {
++ found = true;
++ break;
++ }
++ }
++ }
++ spin_unlock_irq(&efivars->lock);
++
++ if (!found) {
++ kfree(variable_name);
++ break;
++ } else
++ efivar_create_sysfs_entry(efivars,
++ variable_name_size,
++ variable_name, &vendor);
++ }
++}
++
+ /*
+ * Let's not leave out systab information that snuck into
+ * the efivars driver
+@@ -1273,7 +1347,6 @@ out:
+ }
+ EXPORT_SYMBOL_GPL(register_efivars);
+
+-static struct efivars __efivars;
+ static struct efivar_operations ops;
+
+ /*
+@@ -1331,6 +1404,8 @@ err_put:
+ static void __exit
+ efivars_exit(void)
+ {
++ cancel_work_sync(&efivar_work);
++
+ if (efi_enabled(EFI_RUNTIME_SERVICES)) {
+ unregister_efivars(&__efivars);
+ kobject_put(efi_kobj);
+--- a/include/linux/efi.h
++++ b/include/linux/efi.h
+@@ -620,7 +620,8 @@ struct efivars {
+ * 1) ->list - adds, removals, reads, writes
+ * 2) ops.[gs]et_variable() calls.
+ * It must not be held when creating sysfs entries or calling kmalloc.
+- * ops.get_next_variable() is only called from register_efivars(),
++ * ops.get_next_variable() is only called from register_efivars()
++ * or efivar_update_sysfs_entries(),
+ * which is protected by the BKL, so that path is safe.
+ */
+ spinlock_t lock;
Added: dists/sid/linux/debian/patches/bugfix/all/efivars-Add-module-parameter-to-disable-use-as-a-pst.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/efivars-Add-module-parameter-to-disable-use-as-a-pst.patch Fri Mar 22 20:15:09 2013 (r19937)
@@ -0,0 +1,72 @@
+From: Seth Forshee <seth.forshee at canonical.com>
+Date: Mon, 11 Mar 2013 16:17:50 -0500
+Subject: efivars: Add module parameter to disable use as a pstore backend
+
+commit ec0971ba5372a4dfa753f232449d23a8fd98490e upstream.
+
+We know that with some firmware implementations writing too much data to
+UEFI variables can lead to bricking machines. Recent changes attempt to
+address this issue, but for some it may still be prudent to avoid
+writing large amounts of data until the solution has been proven on a
+wide variety of hardware.
+
+Crash dumps or other data from pstore can potentially be a large data
+source. Add a pstore_module parameter to efivars to allow disabling its
+use as a backend for pstore. Also add a config option,
+CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE, to allow setting the default
+value of this paramter to true (i.e. disabled by default).
+
+Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
+Cc: Josh Boyer <jwboyer at redhat.com>
+Cc: Matthew Garrett <mjg59 at srcf.ucam.org>
+Cc: Seiji Aguchi <seiji.aguchi at hds.com>
+Cc: Tony Luck <tony.luck at intel.com>
+Signed-off-by: Matt Fleming <matt.fleming at intel.com>
+[bwh: Backported to 3.2: adjust context]
+---
+ drivers/firmware/Kconfig | 9 +++++++++
+ drivers/firmware/efivars.c | 8 +++++++-
+ 2 files changed, 16 insertions(+), 1 deletion(-)
+
+--- a/drivers/firmware/Kconfig
++++ b/drivers/firmware/Kconfig
+@@ -62,6 +62,15 @@ config EFI_VARS_PSTORE
+ will allow writing console messages, crash dumps, or anything
+ else supported by pstore to EFI variables.
+
++config EFI_VARS_PSTORE_DEFAULT_DISABLE
++ bool "Disable using efivars as a pstore backend by default"
++ depends on EFI_VARS_PSTORE
++ default n
++ help
++ Saying Y here will disable the use of efivars as a storage
++ backend for pstore by default. This setting can be overridden
++ using the efivars module's pstore_disable parameter.
++
+ config EFI_PCDP
+ bool "Console device selection via EFI PCDP or HCDP table"
+ depends on ACPI && EFI && IA64
+--- a/drivers/firmware/efivars.c
++++ b/drivers/firmware/efivars.c
+@@ -93,6 +93,11 @@ MODULE_ALIAS("platform:efivars");
+
+ #define DUMP_NAME_LEN 52
+
++static bool efivars_pstore_disable =
++ IS_ENABLED(EFI_VARS_PSTORE_DEFAULT_DISABLE);
++
++module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
++
+ /*
+ * The maximum size of VariableName + Data = 1024
+ * Therefore, it's reasonable to save that much
+@@ -1258,7 +1263,8 @@ int register_efivars(struct efivars *efi
+ if (error)
+ unregister_efivars(efivars);
+
+- efivar_pstore_register(efivars);
++ if (!efivars_pstore_disable)
++ efivar_pstore_register(efivars);
+
+ out:
+ kfree(variable_name);
Added: dists/sid/linux/debian/patches/bugfix/all/efivars-Allow-disabling-use-as-a-pstore-backend.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/efivars-Allow-disabling-use-as-a-pstore-backend.patch Fri Mar 22 20:15:09 2013 (r19937)
@@ -0,0 +1,142 @@
+From: Seth Forshee <seth.forshee at canonical.com>
+Date: Thu, 7 Mar 2013 11:40:17 -0600
+Subject: efivars: Allow disabling use as a pstore backend
+
+commit ed9dc8ce7a1c8115dba9483a9b51df8b63a2e0ef upstream.
+
+Add a new option, CONFIG_EFI_VARS_PSTORE, which can be set to N to
+avoid using efivars as a backend to pstore, as some users may want to
+compile out the code completely.
+
+Set the default to Y to maintain backwards compatability, since this
+feature has always been enabled until now.
+
+Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
+Cc: Josh Boyer <jwboyer at redhat.com>
+Cc: Matthew Garrett <mjg59 at srcf.ucam.org>
+Cc: Seiji Aguchi <seiji.aguchi at hds.com>
+Cc: Tony Luck <tony.luck at intel.com>
+Signed-off-by: Matt Fleming <matt.fleming at intel.com>
+[bwh: Backported to 3.2: adjust context]
+---
+ drivers/firmware/Kconfig | 9 +++++++
+ drivers/firmware/efivars.c | 64 ++++++++++++++------------------------------
+ 2 files changed, 29 insertions(+), 44 deletions(-)
+
+--- a/drivers/firmware/Kconfig
++++ b/drivers/firmware/Kconfig
+@@ -53,6 +53,15 @@ config EFI_VARS
+ Subsequent efibootmgr releases may be found at:
+ <http://linux.dell.com/efibootmgr>
+
++config EFI_VARS_PSTORE
++ bool "Register efivars backend for pstore"
++ depends on EFI_VARS && PSTORE
++ default y
++ help
++ Say Y here to enable use efivars as a backend to pstore. This
++ will allow writing console messages, crash dumps, or anything
++ else supported by pstore to EFI variables.
++
+ config EFI_PCDP
+ bool "Console device selection via EFI PCDP or HCDP table"
+ depends on ACPI && EFI && IA64
+--- a/drivers/firmware/efivars.c
++++ b/drivers/firmware/efivars.c
+@@ -660,8 +660,6 @@ static struct kobj_type efivar_ktype = {
+ .default_attrs = def_attrs,
+ };
+
+-static struct pstore_info efi_pstore_info;
+-
+ static inline void
+ efivar_unregister(struct efivar_entry *var)
+ {
+@@ -698,7 +696,7 @@ static int efi_status_to_err(efi_status_
+ return err;
+ }
+
+-#ifdef CONFIG_PSTORE
++#ifdef CONFIG_EFI_VARS_PSTORE
+
+ static int efi_pstore_open(struct pstore_info *psi)
+ {
+@@ -848,36 +846,6 @@ static int efi_pstore_erase(enum pstore_
+
+ return 0;
+ }
+-#else
+-static int efi_pstore_open(struct pstore_info *psi)
+-{
+- return 0;
+-}
+-
+-static int efi_pstore_close(struct pstore_info *psi)
+-{
+- return 0;
+-}
+-
+-static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
+- struct timespec *timespec,
+- char **buf, struct pstore_info *psi)
+-{
+- return -1;
+-}
+-
+-static int efi_pstore_write(enum pstore_type_id type, u64 *id,
+- unsigned int part, size_t size, struct pstore_info *psi)
+-{
+- return 0;
+-}
+-
+-static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+- struct pstore_info *psi)
+-{
+- return 0;
+-}
+-#endif
+
+ static struct pstore_info efi_pstore_info = {
+ .owner = THIS_MODULE,
+@@ -889,6 +857,24 @@ static struct pstore_info efi_pstore_inf
+ .erase = efi_pstore_erase,
+ };
+
++static void efivar_pstore_register(struct efivars *efivars)
++{
++ efivars->efi_pstore_info = efi_pstore_info;
++ efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
++ if (efivars->efi_pstore_info.buf) {
++ efivars->efi_pstore_info.bufsize = 1024;
++ efivars->efi_pstore_info.data = efivars;
++ spin_lock_init(&efivars->efi_pstore_info.buf_lock);
++ pstore_register(&efivars->efi_pstore_info);
++ }
++}
++#else
++static void efivar_pstore_register(struct efivars *efivars)
++{
++ return;
++}
++#endif
++
+ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t count)
+@@ -1272,15 +1258,7 @@ int register_efivars(struct efivars *efi
+ if (error)
+ unregister_efivars(efivars);
+
+- efivars->efi_pstore_info = efi_pstore_info;
+-
+- efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
+- if (efivars->efi_pstore_info.buf) {
+- efivars->efi_pstore_info.bufsize = 1024;
+- efivars->efi_pstore_info.data = efivars;
+- spin_lock_init(&efivars->efi_pstore_info.buf_lock);
+- pstore_register(&efivars->efi_pstore_info);
+- }
++ efivar_pstore_register(efivars);
+
+ out:
+ kfree(variable_name);
Added: dists/sid/linux/debian/patches/bugfix/all/efivars-Fix-check-for-CONFIG_EFI_VARS_PSTORE_DEFAULT.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/efivars-Fix-check-for-CONFIG_EFI_VARS_PSTORE_DEFAULT.patch Fri Mar 22 20:15:09 2013 (r19937)
@@ -0,0 +1,24 @@
+From: Ben Hutchings <ben at decadent.org.uk>
+Date: Fri, 22 Mar 2013 19:43:53 +0000
+Subject: efivars: Fix check for CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE
+
+The 'CONFIG_' prefix is not implicit in IS_ENABLED().
+
+Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
+Cc: Seth Forshee <seth.forshee at canonical.com>
+Cc: <stable at vger.kernel.org>
+---
+ drivers/firmware/efivars.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/firmware/efivars.c
++++ b/drivers/firmware/efivars.c
+@@ -94,7 +94,7 @@ MODULE_ALIAS("platform:efivars");
+ #define DUMP_NAME_LEN 52
+
+ static bool efivars_pstore_disable =
+- IS_ENABLED(EFI_VARS_PSTORE_DEFAULT_DISABLE);
++ IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
+
+ module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
+
Added: dists/sid/linux/debian/patches/bugfix/all/efivars-Handle-duplicate-names-from-get_next_variabl.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/efivars-Handle-duplicate-names-from-get_next_variabl.patch Fri Mar 22 20:15:09 2013 (r19937)
@@ -0,0 +1,156 @@
+From: Matt Fleming <matt.fleming at intel.com>
+Date: Thu, 7 Mar 2013 11:59:14 +0000
+Subject: efivars: Handle duplicate names from get_next_variable()
+
+commit e971318bbed610e28bb3fde9d548e6aaf0a6b02e upstream.
+
+Some firmware exhibits a bug where the same VariableName and
+VendorGuid values are returned on multiple invocations of
+GetNextVariableName(). See,
+
+ https://bugzilla.kernel.org/show_bug.cgi?id=47631
+
+As a consequence of such a bug, Andre reports hitting the following
+WARN_ON() in the sysfs code after updating the BIOS on his, "Gigabyte
+Technology Co., Ltd. To be filled by O.E.M./Z77X-UD3H, BIOS F19e
+11/21/2012)" machine,
+
+[ 0.581554] EFI Variables Facility v0.08 2004-May-17
+[ 0.584914] ------------[ cut here ]------------
+[ 0.585639] WARNING: at /home/andre/linux/fs/sysfs/dir.c:536 sysfs_add_one+0xd4/0x100()
+[ 0.586381] Hardware name: To be filled by O.E.M.
+[ 0.587123] sysfs: cannot create duplicate filename '/firmware/efi/vars/SbAslBufferPtrVar-01f33c25-764d-43ea-aeea-6b5a41f3f3e8'
+[ 0.588694] Modules linked in:
+[ 0.589484] Pid: 1, comm: swapper/0 Not tainted 3.8.0+ #7
+[ 0.590280] Call Trace:
+[ 0.591066] [<ffffffff81208954>] ? sysfs_add_one+0xd4/0x100
+[ 0.591861] [<ffffffff810587bf>] warn_slowpath_common+0x7f/0xc0
+[ 0.592650] [<ffffffff810588bc>] warn_slowpath_fmt+0x4c/0x50
+[ 0.593429] [<ffffffff8134dd85>] ? strlcat+0x65/0x80
+[ 0.594203] [<ffffffff81208954>] sysfs_add_one+0xd4/0x100
+[ 0.594979] [<ffffffff81208b78>] create_dir+0x78/0xd0
+[ 0.595753] [<ffffffff81208ec6>] sysfs_create_dir+0x86/0xe0
+[ 0.596532] [<ffffffff81347e4c>] kobject_add_internal+0x9c/0x220
+[ 0.597310] [<ffffffff81348307>] kobject_init_and_add+0x67/0x90
+[ 0.598083] [<ffffffff81584a71>] ? efivar_create_sysfs_entry+0x61/0x1c0
+[ 0.598859] [<ffffffff81584b2b>] efivar_create_sysfs_entry+0x11b/0x1c0
+[ 0.599631] [<ffffffff8158517e>] register_efivars+0xde/0x420
+[ 0.600395] [<ffffffff81d430a7>] ? edd_init+0x2f5/0x2f5
+[ 0.601150] [<ffffffff81d4315f>] efivars_init+0xb8/0x104
+[ 0.601903] [<ffffffff8100215a>] do_one_initcall+0x12a/0x180
+[ 0.602659] [<ffffffff81d05d80>] kernel_init_freeable+0x13e/0x1c6
+[ 0.603418] [<ffffffff81d05586>] ? loglevel+0x31/0x31
+[ 0.604183] [<ffffffff816a6530>] ? rest_init+0x80/0x80
+[ 0.604936] [<ffffffff816a653e>] kernel_init+0xe/0xf0
+[ 0.605681] [<ffffffff816ce7ec>] ret_from_fork+0x7c/0xb0
+[ 0.606414] [<ffffffff816a6530>] ? rest_init+0x80/0x80
+[ 0.607143] ---[ end trace 1609741ab737eb29 ]---
+
+There's not much we can do to work around and keep traversing the
+variable list once we hit this firmware bug. Our only solution is to
+terminate the loop because, as Lingzhu reports, some machines get
+stuck when they encounter duplicate names,
+
+ > I had an IBM System x3100 M4 and x3850 X5 on which kernel would
+ > get stuck in infinite loop creating duplicate sysfs files because,
+ > for some reason, there are several duplicate boot entries in nvram
+ > getting GetNextVariableName into a circle of iteration (with
+ > period > 2).
+
+Also disable the workqueue, as efivar_update_sysfs_entries() uses
+GetNextVariableName() to figure out which variables have been created
+since the last iteration. That algorithm isn't going to work if
+GetNextVariableName() returns duplicates. Note that we don't disable
+EFI variable creation completely on the affected machines, it's just
+that any pstore dump-* files won't appear in sysfs until the next
+boot.
+
+Reported-by: Andre Heider <a.heider at gmail.com>
+Reported-by: Lingzhu Xiang <lxiang at redhat.com>
+Tested-by: Lingzhu Xiang <lxiang at redhat.com>
+Cc: Seiji Aguchi <seiji.aguchi at hds.com>
+Signed-off-by: Matt Fleming <matt.fleming at intel.com>
+[bwh: Backported to 3.2: reason is not checked in efi_pstore_write()]
+---
+ drivers/firmware/efivars.c | 48 +++++++++++++++++++++++++++++++++++++++++++-
+ 1 file changed, 47 insertions(+), 1 deletion(-)
+
+--- a/drivers/firmware/efivars.c
++++ b/drivers/firmware/efivars.c
+@@ -160,6 +160,7 @@ efivar_create_sysfs_entry(struct efivars
+
+ static void efivar_update_sysfs_entries(struct work_struct *);
+ static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
++static bool efivar_wq_enabled = true;
+
+ /* Return the number of unicode characters in data */
+ static unsigned long
+@@ -843,7 +844,8 @@ static int efi_pstore_write(enum pstore_
+ if (found)
+ efivar_unregister(found);
+
+- schedule_work(&efivar_work);
++ if (efivar_wq_enabled)
++ schedule_work(&efivar_work);
+
+ *id = part;
+ return ret;
+@@ -1306,6 +1308,35 @@ void unregister_efivars(struct efivars *
+ }
+ EXPORT_SYMBOL_GPL(unregister_efivars);
+
++/*
++ * Print a warning when duplicate EFI variables are encountered and
++ * disable the sysfs workqueue since the firmware is buggy.
++ */
++static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid,
++ unsigned long len16)
++{
++ size_t i, len8 = len16 / sizeof(efi_char16_t);
++ char *s8;
++
++ /*
++ * Disable the workqueue since the algorithm it uses for
++ * detecting new variables won't work with this buggy
++ * implementation of GetNextVariableName().
++ */
++ efivar_wq_enabled = false;
++
++ s8 = kzalloc(len8, GFP_KERNEL);
++ if (!s8)
++ return;
++
++ for (i = 0; i < len8; i++)
++ s8[i] = s16[i];
++
++ printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
++ s8, vendor_guid);
++ kfree(s8);
++}
++
+ int register_efivars(struct efivars *efivars,
+ const struct efivar_operations *ops,
+ struct kobject *parent_kobj)
+@@ -1348,6 +1379,22 @@ int register_efivars(struct efivars *efi
+ case EFI_SUCCESS:
+ variable_name_size = var_name_strnsize(variable_name,
+ variable_name_size);
++
++ /*
++ * Some firmware implementations return the
++ * same variable name on multiple calls to
++ * get_next_variable(). Terminate the loop
++ * immediately as there is no guarantee that
++ * we'll ever see a different variable name,
++ * and may end up looping here forever.
++ */
++ if (variable_is_present(variable_name, &vendor_guid)) {
++ dup_variable_bug(variable_name, &vendor_guid,
++ variable_name_size);
++ status = EFI_NOT_FOUND;
++ break;
++ }
++
+ efivar_create_sysfs_entry(efivars,
+ variable_name_size,
+ variable_name,
Added: dists/sid/linux/debian/patches/bugfix/all/efivars-explicitly-calculate-length-of-VariableName.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/efivars-explicitly-calculate-length-of-VariableName.patch Fri Mar 22 20:15:09 2013 (r19937)
@@ -0,0 +1,101 @@
+From: Matt Fleming <matt.fleming at intel.com>
+Date: Fri, 1 Mar 2013 14:49:12 +0000
+Subject: efivars: explicitly calculate length of VariableName
+
+commit ec50bd32f1672d38ddce10fb1841cbfda89cfe9a upstream.
+
+It's not wise to assume VariableNameSize represents the length of
+VariableName, as not all firmware updates VariableNameSize in the same
+way (some don't update it at all if EFI_SUCCESS is returned). There
+are even implementations out there that update VariableNameSize with
+values that are both larger than the string returned in VariableName
+and smaller than the buffer passed to GetNextVariableName(), which
+resulted in the following bug report from Michael Schroeder,
+
+ > On HP z220 system (firmware version 1.54), some EFI variables are
+ > incorrectly named :
+ >
+ > ls -d /sys/firmware/efi/vars/*8be4d* | grep -v -- -8be returns
+ > /sys/firmware/efi/vars/dbxDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c
+ > /sys/firmware/efi/vars/KEKDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c
+ > /sys/firmware/efi/vars/SecureBoot-pport8be4df61-93ca-11d2-aa0d-00e098032b8c
+ > /sys/firmware/efi/vars/SetupMode-Information8be4df61-93ca-11d2-aa0d-00e098032b8c
+
+The issue here is that because we blindly use VariableNameSize without
+verifying its value, we can potentially read garbage values from the
+buffer containing VariableName if VariableNameSize is larger than the
+length of VariableName.
+
+Since VariableName is a string, we can calculate its size by searching
+for the terminating NULL character.
+
+Reported-by: Frederic Crozat <fcrozat at suse.com>
+Cc: Matthew Garrett <mjg59 at srcf.ucam.org>
+Cc: Josh Boyer <jwboyer at redhat.com>
+Cc: Michael Schroeder <mls at suse.com>
+Cc: Lee, Chun-Yi <jlee at suse.com>
+Cc: Lingzhu Xiang <lxiang at redhat.com>
+Cc: Seiji Aguchi <seiji.aguchi at hds.com>
+Signed-off-by: Matt Fleming <matt.fleming at intel.com>
+---
+ drivers/firmware/efivars.c | 32 +++++++++++++++++++++++++++++++-
+ 1 file changed, 31 insertions(+), 1 deletion(-)
+
+--- a/drivers/firmware/efivars.c
++++ b/drivers/firmware/efivars.c
+@@ -1044,6 +1044,31 @@ static bool variable_is_present(efi_char
+ return found;
+ }
+
++/*
++ * Returns the size of variable_name, in bytes, including the
++ * terminating NULL character, or variable_name_size if no NULL
++ * character is found among the first variable_name_size bytes.
++ */
++static unsigned long var_name_strnsize(efi_char16_t *variable_name,
++ unsigned long variable_name_size)
++{
++ unsigned long len;
++ efi_char16_t c;
++
++ /*
++ * The variable name is, by definition, a NULL-terminated
++ * string, so make absolutely sure that variable_name_size is
++ * the value we expect it to be. If not, return the real size.
++ */
++ for (len = 2; len <= variable_name_size; len += sizeof(c)) {
++ c = variable_name[(len / sizeof(c)) - 1];
++ if (!c)
++ break;
++ }
++
++ return min(len, variable_name_size);
++}
++
+ static void efivar_update_sysfs_entries(struct work_struct *work)
+ {
+ struct efivars *efivars = &__efivars;
+@@ -1084,10 +1109,13 @@ static void efivar_update_sysfs_entries(
+ if (!found) {
+ kfree(variable_name);
+ break;
+- } else
++ } else {
++ variable_name_size = var_name_strnsize(variable_name,
++ variable_name_size);
+ efivar_create_sysfs_entry(efivars,
+ variable_name_size,
+ variable_name, &vendor);
++ }
+ }
+ }
+
+@@ -1318,6 +1346,8 @@ int register_efivars(struct efivars *efi
+ &vendor_guid);
+ switch (status) {
+ case EFI_SUCCESS:
++ variable_name_size = var_name_strnsize(variable_name,
++ variable_name_size);
+ efivar_create_sysfs_entry(efivars,
+ variable_name_size,
+ variable_name,
Modified: dists/sid/linux/debian/patches/series
==============================================================================
--- dists/sid/linux/debian/patches/series Fri Mar 22 18:24:45 2013 (r19936)
+++ dists/sid/linux/debian/patches/series Fri Mar 22 20:15:09 2013 (r19937)
@@ -627,3 +627,9 @@
bugfix/all/udf-avoid-info-leak-on-export.patch
bugfix/all/isofs-avoid-info-leak-on-export.patch
debian/dm-avoid-ABI-change-in-3.2.41.patch
+bugfix/all/efivars-Allow-disabling-use-as-a-pstore-backend.patch
+bugfix/all/efivars-Add-module-parameter-to-disable-use-as-a-pst.patch
+bugfix/all/efivars-Fix-check-for-CONFIG_EFI_VARS_PSTORE_DEFAULT.patch
+bugfix/all/efi_pstore-Introducing-workqueue-updating-sysfs.patch
+bugfix/all/efivars-explicitly-calculate-length-of-VariableName.patch
+bugfix/all/efivars-Handle-duplicate-names-from-get_next_variabl.patch
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